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Fri Sep 12 15:21:34 2008 UTC (11 years, 2 months ago) by gage
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Make sure $attempts is properly defined

    1 
    2 
    3 ####################################################################
    4 # Copyright @ 1995-1998 University of Rochester
    5 # All Rights Reserved
    6 ####################################################################
    7 
    8 =head1 NAME
    9 
   10     PGbasicmacros.pl --- located in the courseScripts directory
   11 
   12 =head1 SYNPOSIS
   13 
   14 
   15 
   16 =head1 DESCRIPTION
   17 
   18 
   19 
   20 =cut
   21 
   22 # this is equivalent to use strict, but can be used within the Safe compartment.
   23 BEGIN{
   24   be_strict;
   25 }
   26 
   27 
   28 my $displayMode;
   29 
   30 my ($PAR,
   31   $BR,
   32   $LQ,
   33   $RQ,
   34   $BM,
   35   $EM,
   36   $BDM,
   37   $EDM,
   38   $LTS,
   39   $GTS,
   40   $LTE,
   41   $GTE,
   42   $BEGIN_ONE_COLUMN,
   43   $END_ONE_COLUMN,
   44   $SOL,
   45   $SOLUTION,
   46   $HINT,
   47   $COMMENT,
   48   $US,
   49   $SPACE,
   50   $BBOLD,
   51   $EBOLD,
   52   $BITALIC,
   53   $EITALIC,
   54   $BCENTER,
   55   $ECENTER,
   56   $HR,
   57   $LBRACE,
   58   $RBRACE,
   59   $LB,
   60   $RB,
   61   $DOLLAR,
   62   $PERCENT,
   63   $CARET,
   64   $PI,
   65   $E,
   66   @ALPHABET,
   67   $envir,
   68   $PG_random_generator,
   69   $inputs_ref,
   70   $rh_sticky_answers,
   71   $r_ans_rule_count,
   72   );
   73 
   74 sub _PGbasicmacros_init {
   75     # The big problem is that at compile time in the cached Safe compartment
   76     # main:: has one definition, probably Safe::Root1::
   77     # At runtime main has another definition Safe::Rootx:: where x is > 1
   78 
   79     # It is important to
   80     # initialize the my variable version of $displayMode from the "runtime" version
   81     # of main::displayMode
   82 
   83     $displayMode         =    main::PG_restricted_eval(q!$main::displayMode!);
   84 
   85 # This is initializes the remaining variables in the runtime main:: compartment.
   86 
   87 main::PG_restricted_eval( <<'EndOfFile');
   88     $displayMode            = $displayMode;
   89 
   90   $main::PAR        = PAR();
   91   $main::BR       = BR();
   92   $main::LQ       = LQ();
   93   $main::RQ       = RQ();
   94   $main::BM       = BM();
   95   $main::EM       = EM();
   96   $main::BDM        = BDM();
   97   $main::EDM        = EDM();
   98   $main::LTS        = LTS();
   99   $main::GTS        = GTS();
  100   $main::LTE        = LTE();
  101   $main::GTE        = GTE();
  102   $main::BEGIN_ONE_COLUMN = BEGIN_ONE_COLUMN();
  103   $main::END_ONE_COLUMN = END_ONE_COLUMN();
  104   $main::SOL        = SOLUTION_HEADING();
  105   $main::SOLUTION     = SOLUTION_HEADING();
  106   $main::HINT       = HINT_HEADING();
  107   $main::US       = US();
  108   $main::SPACE      = SPACE();
  109   $main::BBOLD      = BBOLD();
  110   $main::EBOLD      = EBOLD();
  111   $main::BITALIC      = BITALIC();
  112   $main::EITALIC          = EITALIC();
  113   $main::BCENTER          = BCENTER();
  114   $main::ECENTER          = ECENTER();
  115   $main::HR       = HR();
  116   $main::LBRACE     = LBRACE();
  117   $main::RBRACE     = RBRACE();
  118   $main::LB       = LB();
  119   $main::RB       = RB();
  120   $main::DOLLAR     = DOLLAR();
  121   $main::PERCENT      = PERCENT();
  122   $main::CARET      = CARET();
  123   $main::PI       = PI();
  124   $main::E        = E();
  125   @main::ALPHABET     = ('A'..'ZZ');
  126   %main::STICKY_ANSWERS   = ();
  127 
  128 
  129 EndOfFile
  130 
  131 # Next we transfer the correct definitions in the main:: compartment to the local my variables
  132 # This can't be done inside the eval above because my variables seem to be invisible inside the eval
  133 
  134 
  135     $PAR         = PAR();
  136   $BR            = BR();
  137   $LQ            = LQ();
  138   $RQ            = RQ();
  139   $BM            = BM();
  140   $EM            = EM();
  141   $BDM         = BDM();
  142   $EDM         = EDM();
  143   $LTS         = LTS();
  144   $GTS         = GTS();
  145   $LTE         = LTE();
  146   $GTE         = GTE();
  147   $BEGIN_ONE_COLUMN  = BEGIN_ONE_COLUMN();
  148   $END_ONE_COLUMN      = END_ONE_COLUMN();
  149   $SOL         = SOLUTION_HEADING();
  150   $SOLUTION      = SOLUTION_HEADING();
  151   $HINT        = HINT_HEADING();
  152   $US            = US();
  153   $SPACE           = SPACE();
  154   $BBOLD           = BBOLD();
  155   $EBOLD           = EBOLD();
  156   $BITALIC       = BITALIC();
  157   $EITALIC             = EITALIC();
  158   $BCENTER             = BCENTER();
  159   $ECENTER             = ECENTER();
  160   $HR            = HR();
  161   $LBRACE          = LBRACE();
  162   $RBRACE          = RBRACE();
  163   $LB            = LB();
  164   $RB            = RB();
  165   $DOLLAR          = DOLLAR();
  166   $PERCENT       = PERCENT();
  167   $CARET           = CARET();
  168   $PI            = PI();
  169   $E             = E();
  170   @ALPHABET      = ('A'..'ZZ');
  171 
  172    $envir               = PG_restricted_eval(q!\%main::envir!);
  173    $PG_random_generator = PG_restricted_eval(q!$main::PG_random_generator!);
  174    $inputs_ref          = $envir{inputs_ref};
  175    $rh_sticky_answers   = PG_restricted_eval(q!\%main::STICKY_ANSWERS!);
  176    $r_ans_rule_count     = PG_restricted_eval(q!\$ans_rule_count!);
  177 }
  178 
  179 =head2  Answer blank macros:
  180 
  181 These produce answer blanks of various sizes or pop up lists or radio answer buttons.
  182 The names for the answer blanks are
  183 generated implicitly.
  184 
  185   ans_rule( width )
  186   tex_ans_rule( width )
  187   ans_radio_buttons(value1=>label1, value2,label2 => value3,label3=>...)
  188   pop_up_list(@list)   # list consists of (value => label,  PR => "Product rule",...)
  189   pop_up_list([@list]) # list consists of values
  190 
  191 In the last case, one can use C<pop_up_list(['?', 'yes', 'no'])> to produce a
  192 pop-up list containing the three strings listed, and then use str_cmp to check
  193 the answer.
  194 
  195 To indicate the checked position of radio buttons put a '%' in front of the value: C<ans_radio_buttons(1, 'Yes','%2','No')>
  196 will have 'No' checked.  C<tex_ans_rule> works inside math equations in C<HTML_tth> mode.  It does not work in C<Latex2HTML> mode
  197 since this mode produces gif pictures.
  198 
  199 
  200 The following method is defined in F<PG.pl> for entering the answer evaluators corresponding
  201 to answer rules with automatically generated names.  The answer evaluators are matched with the
  202 answer rules in the order in which they appear on the page.
  203 
  204   ANS(ans_evaluator1, ans_evaluator2,...);
  205 
  206 These are more primitive macros which produce answer blanks for specialized cases when complete
  207 control over the matching of answers blanks and answer evaluators is desired.
  208 The names of the answer blanks must be generated manually, and it is best if they do NOT begin
  209 with the default answer prefix (currently AnSwEr).
  210 
  211   labeled_ans_rule(name, width)  # an alias for NAMED_ANS_RULE where width defaults to 20 if omitted.
  212 
  213   NAMED_ANS_RULE(name, width)
  214   NAMED_ANS_BOX(name, rows, cols)
  215   NAMED_ANS_RADIO(name, value,label,)
  216   NAMED_ANS_RADIO_EXTENSION(name, value,label)
  217   NAMED_ANS_RADIO_BUTTONS(name,value1,label1,value2,label2,...)
  218   check_box('-name' =>answer5,'-value' =>'statement3','-label' =>'I loved this course!'   )
  219   NAMED_POP_UP_LIST($name, @list) # list consists of (value => tag,  PR => "Product rule",...)
  220   NAMED_POP_UP_LIST($name, [@list]) # list consists of a list of values (and each tag will be set to the corresponding value)
  221 
  222 (Name is the name of the variable, value is the value given to the variable when this option is selected,
  223 and label is the text printed next to the button or check box.    Check box variables can have multiple values.)
  224 
  225 NAMED_ANS_RADIO_BUTTONS creates a sequence of NAMED_ANS_RADIO and NAMED_ANS_RADIO_EXTENSION  items which
  226 are  output either as an array or, in scalar context, as the array glued together with spaces.  It is
  227 usually easier to use this than to manually construct the radio buttons by hand.  However, sometimes
  228  extra flexibility is desiredin which case:
  229 
  230 When entering radio buttons using the "NAMED" format, you should use NAMED_ANS_RADIO button for the first button
  231 and then use NAMED_ANS_RADIO_EXTENSION for the remaining buttons.  NAMED_ANS_RADIO requires a matching answer evalutor,
  232 while NAMED_ANS_RADIO_EXTENSION does not. The name used for NAMED_ANS_RADIO_EXTENSION should match the name
  233 used for NAMED_ANS_RADIO (and the associated answer evaluator).
  234 
  235 
  236 The following method is defined in  F<PG.pl> for entering the answer evaluators corresponding
  237 to answer rules with automatically generated names.  The answer evaluators are matched with the
  238 answer rules in the order in which they appear on the page.
  239 
  240       NAMED_ANS(name1 => ans_evaluator1, name2 => ans_evaluator2,...);
  241 
  242 These auxiliary macros are defined in PG.pl
  243 
  244 
  245   NEW_ANS_NAME( number );   # produces a new answer blank name from a number by adding a prefix (AnSwEr)
  246                             # and registers this name as an implicitly labeled answer
  247                             # Its use is paired with each answer evaluator being entered using ANS()
  248 
  249     ANS_NUM_TO_NAME(number);  # adds the prefix (AnSwEr) to the number, but does nothing else.
  250 
  251   RECORD_ANS_NAME( name );  # records the order in which the answer blank  is rendered
  252                             # This is called by all of the constructs above, but must
  253                             # be called explicitly if an input blank is constructed explictly
  254                             # using HTML code.
  255 
  256 These are legacy macros:
  257 
  258   ANS_RULE( number, width );                  # equivalent to NAMED_ANS_RULE( NEW_ANS_NAME(number), width)
  259   ANS_BOX( question_number,height, width );       # equivalent to NAMED_ANS_BOX( NEW_ANS_NAME(number), height, width)
  260   ANS_RADIO( question_number, value,tag );        # equivalent to NAMED_ANS_RADIO( NEW_ANS_NAME(number), value,tag)
  261   ANS_RADIO_OPTION( question_number, value,tag );   # equivalent to NAMED_ANS_RADIO_EXTENSION( ANS_NUM_TO_NAME(number), value,tag)
  262 
  263 
  264 =cut
  265 
  266 
  267 
  268 sub labeled_ans_rule {   # syntactic sugar for NAMED_ANS_RULE
  269   my($name,$col) = @_;
  270   $col = 20 unless defined($col);
  271   NAMED_ANS_RULE($name,$col);
  272 }
  273 
  274 sub NAMED_ANS_RULE {
  275   my($name,$col) = @_;
  276   my $answer_value = '';
  277   $answer_value = ${$inputs_ref}{$name} if    defined(${$inputs_ref}{$name});
  278     if ($answer_value =~ /\0/ ) {
  279       my @answers = split("\0", $answer_value);
  280       $answer_value = shift(@answers);  # use up the first answer
  281       $rh_sticky_answers->{$name}=\@answers;
  282       # store the rest -- beacuse this stores to a main:; variable
  283       # it must be evaluated at run time
  284       $answer_value= '' unless defined($answer_value);
  285   } elsif (ref($answer_value) eq 'ARRAY') {
  286     my @answers = @{ $answer_value};
  287       $answer_value = shift(@answers);  # use up the first answer
  288       $rh_sticky_answers->{$name}=\@answers;
  289       # store the rest -- beacuse this stores to a main:; variable
  290       # it must be evaluated at run time
  291       $answer_value= '' unless defined($answer_value);
  292   }
  293 
  294   $answer_value =~ tr/\\$@`//d;   #`## make sure student answers can not be interpolated by e.g. EV3
  295   $answer_value =~ s/\s+/ /g;     ## remove excessive whitespace from student answer
  296   $name = RECORD_ANS_NAME($name);
  297 
  298   my $tcol = $col/2 > 3 ? $col/2 : 3;  ## get max
  299   $tcol = $tcol < 40 ? $tcol : 40;     ## get min
  300 
  301   MODES(
  302     TeX => "\\mbox{\\parbox[t]{${tcol}ex}{\\hrulefill}}",
  303     Latex2HTML => qq!\\begin{rawhtml}<INPUT TYPE=TEXT SIZE=$col NAME=\"$name\" VALUE = \"\">\\end{rawhtml}!,
  304     HTML => qq!<INPUT TYPE=TEXT SIZE=$col NAME="$name" VALUE="$answer_value">!.
  305                         qq!<INPUT TYPE=HIDDEN  NAME="previous_$name" VALUE="$answer_value">!
  306   );
  307 }
  308 
  309 sub NAMED_HIDDEN_ANS_RULE { # this is used to hold information being passed into and out of applets
  310                             # -- preserves state -- identical to NAMED_ANS_RULE except input type "hidden"
  311   my($name,$col) = @_;
  312   my $answer_value = '';
  313   $answer_value = ${$inputs_ref}{$name} if    defined(${$inputs_ref}{$name});
  314     if ($answer_value =~ /\0/ ) {
  315       my @answers = split("\0", $answer_value);
  316       $answer_value = shift(@answers);  # use up the first answer
  317       $rh_sticky_answers->{$name}=\@answers;
  318       # store the rest -- beacuse this stores to a main:; variable
  319       # it must be evaluated at run time
  320       $answer_value= '' unless defined($answer_value);
  321   } elsif (ref($answer_value) eq 'ARRAY') {
  322     my @answers = @{ $answer_value};
  323       $answer_value = shift(@answers);  # use up the first answer
  324       $rh_sticky_answers->{$name}=\@answers;
  325       # store the rest -- beacuse this stores to a main:; variable
  326       # it must be evaluated at run time
  327       $answer_value= '' unless defined($answer_value);
  328   }
  329 
  330   $answer_value =~ tr/\\$@`//d;   #`## make sure student answers can not be interpolated by e.g. EV3
  331   $answer_value =~ s/\s+/ /g;     ## remove excessive whitespace from student answer
  332   $name = RECORD_ANS_NAME($name);
  333 
  334   my $tcol = $col/2 > 3 ? $col/2 : 3;  ## get max
  335   $tcol = $tcol < 40 ? $tcol : 40;     ## get min
  336 
  337   MODES(
  338     TeX => "\\mbox{\\parbox[t]{${tcol}ex}{\\hrulefill}}",
  339     Latex2HTML => qq!\\begin{rawhtml}<INPUT TYPE=TEXT SIZE=$col NAME=\"$name\" VALUE = \"\">\\end{rawhtml}!,
  340     HTML => qq!<INPUT TYPE=HIDDEN SIZE=$col NAME="$name" VALUE="$answer_value">!.
  341                         qq!<INPUT TYPE=HIDDEN  NAME="previous_$name" VALUE="$answer_value">!
  342   );
  343 }
  344 sub NAMED_ANS_RULE_OPTION {   # deprecated
  345   &NAMED_ANS_RULE_EXTENSION;
  346 }
  347 
  348 sub NAMED_ANS_RULE_EXTENSION {
  349   my($name,$col) = @_;
  350   my $answer_value = '';
  351   $answer_value = ${$inputs_ref}{$name} if defined(${$inputs_ref}{$name});
  352   if ( defined( $rh_sticky_answers->{$name} ) ) {
  353     $answer_value = shift( @{ $rh_sticky_answers->{$name} });
  354     $answer_value = '' unless defined($answer_value);
  355   }
  356   $answer_value =~ tr/\\$@`//d;   #`## make sure student answers can not be interpolated by e.g. EV3
  357   $answer_value =~ s/\s+/ /g;     ## remove excessive whitespace from student answer
  358   my $tcol = $col/2 > 3 ? $col/2 : 3;  ## get max
  359   $tcol = $tcol < 40 ? $tcol : 40;     ## get min
  360   MODES(
  361     TeX => "\\mbox{\\parbox[t]{${tcol}ex}{\\hrulefill}}",
  362     Latex2HTML => qq!\\begin{rawhtml}\n<INPUT TYPE=TEXT SIZE=$col NAME=\"$name\" VALUE = \"\">\n\\end{rawhtml}\n!,
  363     HTML => qq!<INPUT TYPE=TEXT SIZE=$col NAME = "$name" VALUE = "$answer_value">!.
  364                         qq!<INPUT TYPE=HIDDEN  NAME="previous_$name" VALUE = "$answer_value">!
  365   );
  366 }
  367 
  368 sub ANS_RULE {  #deprecated
  369   my($number,$col) = @_;
  370   my $name = NEW_ANS_NAME($number);
  371     NAMED_ANS_RULE($name,$col);
  372 }
  373 
  374 
  375 sub  NAMED_ANS_BOX {
  376   my($name,$row,$col) = @_;
  377   $row = 10 unless defined($row);
  378   $col = 80 unless defined($col);
  379   $name = RECORD_ANS_NAME($name);
  380   my $height = .07*$row;
  381   my $answer_value = '';
  382   $answer_value = $inputs_ref->{$name} if defined( $inputs_ref->{$name} );
  383 # $answer_value =~ tr/\\$@`//d;   #`## make sure student answers can not be interpolated by e.g. EV3
  384   my $out = M3(
  385        qq!\\vskip $height in \\hrulefill\\quad !,
  386        qq!\\begin{rawhtml}<TEXTAREA NAME="$name" ROWS="$row" COLS="$col"
  387                WRAP="VIRTUAL">$answer_value</TEXTAREA>\\end{rawhtml}!,
  388          qq!<TEXTAREA NAME="$name" ROWS="$row" COLS="$col"
  389                WRAP="VIRTUAL">$answer_value</TEXTAREA>
  390              <INPUT TYPE=HIDDEN  NAME="previous_$name" VALUE = "$answer_value">
  391            !
  392          );
  393   $out;
  394 }
  395 
  396 sub  ANS_BOX { #deprecated
  397   my($number,$row,$col) = @_;
  398   my $name = NEW_ANS_NAME($number);
  399     NAMED_ANS_BOX($name,$row,$col);
  400 }
  401 
  402 sub NAMED_ANS_RADIO {
  403   my $name = shift;
  404   my $value = shift;
  405     my $tag =shift;
  406     $name = RECORD_ANS_NAME($name);
  407     my $checked = '';
  408     if ($value =~/^\%/) {
  409       $value =~ s/^\%//;
  410       $checked = 'CHECKED'
  411     }
  412   if (defined($inputs_ref->{$name}) ) {
  413     if ($inputs_ref->{$name} eq $value) {
  414       $checked = 'CHECKED'
  415     } else {
  416       $checked = '';
  417     }
  418 
  419     }
  420 
  421   MODES(
  422     TeX => qq!\\item{$tag}\n!,
  423     Latex2HTML => qq!\\begin{rawhtml}\n<INPUT TYPE=RADIO NAME="$name" VALUE="$value" $checked>\\end{rawhtml}$tag!,
  424     HTML => qq!<INPUT TYPE=RADIO NAME="$name" VALUE="$value" $checked>$tag!
  425   );
  426 
  427 }
  428 
  429 sub NAMED_ANS_RADIO_OPTION { #deprecated
  430   &NAMED_ANS_RADIO_EXTENSION;
  431 }
  432 
  433 sub NAMED_ANS_RADIO_EXTENSION {
  434   my $name = shift;
  435   my $value = shift;
  436   my $tag =shift;
  437 
  438 
  439     my $checked = '';
  440     if ($value =~/^\%/) {
  441       $value =~ s/^\%//;
  442       $checked = 'CHECKED'
  443     }
  444   if (defined($inputs_ref->{$name}) ) {
  445     if ($inputs_ref->{$name} eq $value) {
  446       $checked = 'CHECKED'
  447     } else {
  448       $checked = '';
  449     }
  450 
  451     }
  452 
  453   MODES(
  454     TeX => qq!\\item{$tag}\n!,
  455     Latex2HTML => qq!\\begin{rawhtml}\n<INPUT TYPE=RADIO NAME="$name" VALUE="$value" $checked>\\end{rawhtml}$tag!,
  456     HTML => qq!<INPUT TYPE=RADIO NAME="$name" VALUE="$value" $checked>$tag!
  457   );
  458 
  459 }
  460 
  461 sub NAMED_ANS_RADIO_BUTTONS {
  462     my $name  =shift;
  463     my $value = shift;
  464     my $tag = shift;
  465 
  466 
  467   my @out = ();
  468   push(@out, NAMED_ANS_RADIO($name, $value,$tag));
  469   my @buttons = @_;
  470   while (@buttons) {
  471     $value = shift @buttons;  $tag = shift @buttons;
  472     push(@out, NAMED_ANS_RADIO_OPTION($name, $value,$tag));
  473   }
  474   (wantarray) ? @out : join(" ",@out);
  475 }
  476 sub ANS_RADIO {
  477   my $number = shift;
  478   my $value = shift;
  479   my $tag =shift;
  480     my $name = NEW_ANS_NAME($number);
  481   NAMED_ANS_RADIO($name,$value,$tag);
  482 }
  483 
  484 sub ANS_RADIO_OPTION {
  485   my $number = shift;
  486   my $value = shift;
  487   my $tag =shift;
  488 
  489 
  490     my $name = ANS_NUM_TO_NAME($number);
  491   NAMED_ANS_RADIO_OPTION($name,$value,$tag);
  492 }
  493 sub ANS_RADIO_BUTTONS {
  494     my $number  =shift;
  495     my $value = shift;
  496     my $tag = shift;
  497 
  498 
  499   my @out = ();
  500   push(@out, ANS_RADIO($number, $value,$tag));
  501   my @buttons = @_;
  502   while (@buttons) {
  503       $value = shift @buttons; $tag = shift @buttons;
  504     push(@out, ANS_RADIO_OPTION($number, $value,$tag));
  505   }
  506   (wantarray) ? @out : join(" ",@out);
  507 }
  508 ##############################################
  509 #   contained_in( $elem, $array_reference or null separated string);
  510 #   determine whether element is equal
  511 #   ( in the sense of eq,  not ==, ) to an element in the array.
  512 ##############################################
  513 sub contained_in {
  514   my $element = shift;
  515   my @input_list    = @_;
  516   my @output_list = ();
  517   # Expand the list -- convert references to  arrays to arrays
  518   # Convert null separated strings to arrays
  519   foreach my $item   (@input_list ) {
  520     if ($item =~ /\0/) {
  521       push @output_list,   split('\0', $item);
  522      } elsif (ref($item) =~/ARRAY/) {
  523       push @output_list, @{$item};
  524      } else {
  525       push @output_list, $item;
  526      }
  527   }
  528 
  529   my @match_list = grep {$element eq $_ } @output_list;
  530   if ( @match_list ) {
  531     return 1;
  532   } else {
  533     return 0;
  534   }
  535 }
  536 
  537 ##########################
  538 # If multiple boxes are checked then the $inputs_ref->{name }will be a null separated string
  539 # or a reference to an array.
  540 ##########################
  541 
  542 sub NAMED_ANS_CHECKBOX {
  543   my $name = shift;
  544   my $value = shift;
  545     my $tag =shift;
  546     $name = RECORD_ANS_NAME($name);
  547 
  548     my $checked = '';
  549     if ($value =~/^\%/) {
  550       $value =~ s/^\%//;
  551       $checked = 'CHECKED'
  552     }
  553 
  554   if (defined($inputs_ref->{$name}) ) {
  555     if ( contained_in($value, $inputs_ref->{$name} ) ) {
  556       $checked = 'CHECKED'
  557     }
  558     else {
  559       $checked = '';
  560     }
  561 
  562     }
  563 
  564   MODES(
  565     TeX => qq!\\item{$tag}\n!,
  566     Latex2HTML => qq!\\begin{rawhtml}\n<INPUT TYPE=CHECKBOX NAME="$name" VALUE="$value" $checked>\\end{rawhtml}$tag!,
  567     HTML => qq!<INPUT TYPE=CHECKBOX NAME="$name" VALUE="$value" $checked>$tag!
  568   );
  569 
  570 }
  571 
  572 sub NAMED_ANS_CHECKBOX_OPTION {
  573   my $name = shift;
  574   my $value = shift;
  575   my $tag =shift;
  576 
  577     my $checked = '';
  578     if ($value =~/^\%/) {
  579       $value =~ s/^\%//;
  580       $checked = 'CHECKED'
  581     }
  582 
  583   if (defined($inputs_ref->{$name}) ) {
  584     if ( contained_in($value, $inputs_ref->{$name}) ) {
  585       $checked = 'CHECKED'
  586     }
  587     else {
  588       $checked = '';
  589     }
  590 
  591     }
  592 
  593   MODES(
  594     TeX => qq!\\item{$tag}\n!,
  595     Latex2HTML => qq!\\begin{rawhtml}\n<INPUT TYPE=CHECKBOX NAME="$name" VALUE="$value" $checked>\\end{rawhtml}$tag!,
  596     HTML => qq!<INPUT TYPE=CHECKBOX NAME="$name" VALUE="$value" $checked>$tag!
  597   );
  598 
  599 }
  600 
  601 sub NAMED_ANS_CHECKBOX_BUTTONS {
  602     my $name  =shift;
  603     my $value = shift;
  604     my $tag = shift;
  605 
  606   my @out = ();
  607   push(@out, NAMED_ANS_CHECKBOX($name, $value,$tag));
  608 
  609   my @buttons = @_;
  610   while (@buttons) {
  611     $value = shift @buttons;  $tag = shift @buttons;
  612     push(@out, NAMED_ANS_CHECKBOX_OPTION($name, $value,$tag));
  613   }
  614 
  615   (wantarray) ? @out : join(" ",@out);
  616 }
  617 
  618 sub ANS_CHECKBOX {
  619   my $number = shift;
  620   my $value = shift;
  621   my $tag =shift;
  622     my $name = NEW_ANS_NAME($number);
  623 
  624   NAMED_ANS_CHECKBOX($name,$value,$tag);
  625 }
  626 
  627 sub ANS_CHECKBOX_OPTION {
  628   my $number = shift;
  629   my $value = shift;
  630   my $tag =shift;
  631     my $name = ANS_NUM_TO_NAME($number);
  632 
  633   NAMED_ANS_CHECKBOX_OPTION($name,$value,$tag);
  634 }
  635 
  636 
  637 
  638 sub ANS_CHECKBOX_BUTTONS {
  639     my $number  =shift;
  640     my $value = shift;
  641     my $tag = shift;
  642 
  643   my @out = ();
  644   push(@out, ANS_CHECKBOX($number, $value, $tag));
  645 
  646   my @buttons = @_;
  647   while (@buttons) {
  648     $value = shift @buttons;  $tag = shift @buttons;
  649     push(@out, ANS_CHECKBOX_OPTION($number, $value,$tag));
  650   }
  651 
  652   (wantarray) ? @out : join(" ",@out);
  653 }
  654 
  655 sub ans_rule {
  656   my $len = shift;     # gives the optional length of the answer blank
  657   $len    = 20 unless $len ;
  658   my $name = NEW_ANS_NAME(inc_ans_rule_count());
  659   NAMED_ANS_RULE($name ,$len);
  660 }
  661 sub ans_rule_extension {
  662   my $len = shift;
  663     $len    = 20 unless $len ;
  664   my $name = NEW_ANS_NAME($$r_ans_rule_count);  # don't update the answer name
  665   NAMED_ANS_RULE($name ,$len);
  666 }
  667 sub ans_radio_buttons {
  668   my $name  = NEW_ANS_NAME(inc_ans_rule_count());
  669   my @radio_buttons = NAMED_ANS_RADIO_BUTTONS($name, @_);
  670 
  671   if ($displayMode eq 'TeX') {
  672     $radio_buttons[0] = "\n\\begin{itemize}\n" . $radio_buttons[0];
  673     $radio_buttons[$#radio_buttons] .= "\n\\end{itemize}\n";
  674   }
  675 
  676   (wantarray) ? @radio_buttons: join(" ", @radio_buttons);
  677 }
  678 
  679 #added 6/14/2000 by David Etlinger
  680 sub ans_checkbox {
  681   my $name = NEW_ANS_NAME( inc_ans_rule_count() );
  682   my @checkboxes = NAMED_ANS_CHECKBOX_BUTTONS( $name, @_ );
  683 
  684   if ($displayMode eq 'TeX') {
  685     $checkboxes[0] = "\n\\begin{itemize}\n" . $checkboxes[0];
  686     $checkboxes[$#checkboxes] .= "\n\\end{itemize}\n";
  687   }
  688 
  689   (wantarray) ? @checkboxes: join(" ", @checkboxes);
  690 }
  691 
  692 
  693 ## define a version of ans_rule which will work inside TeX math mode or display math mode -- at least for tth mode.
  694 ## This is great for displayed fractions.
  695 ## This will not work with latex2HTML mode since it creates gif equations.
  696 
  697 sub tex_ans_rule {
  698   my $len = shift;
  699   $len    = 20 unless $len ;
  700     my $name = NEW_ANS_NAME(inc_ans_rule_count());
  701     my $answer_rule = NAMED_ANS_RULE($name ,$len);  # we don't want to create three answer rules in different modes.
  702     my $out = MODES(
  703                      'TeX' => $answer_rule,
  704                      'Latex2HTML' => '\\fbox{Answer boxes cannot be placed inside typeset equations}',
  705                      'HTML_tth' => '\\begin{rawhtml} '. $answer_rule.'\\end{rawhtml}',
  706                      'HTML_dpng' => '\\fbox{Answer boxes cannot be placed inside typeset equations}',
  707                      'HTML'     => $answer_rule
  708                    );
  709 
  710     $out;
  711 }
  712 sub tex_ans_rule_extension {
  713   my $len = shift;
  714   $len    = 20 unless $len ;
  715     my $name = NEW_ANS_NAME($$r_ans_rule_count);
  716     my $answer_rule = NAMED_ANS_RULE($name ,$len);  # we don't want to create three answer rules in different modes.
  717     my $out = MODES(
  718                      'TeX' => $answer_rule,
  719                      'Latex2HTML' => '\fbox{Answer boxes cannot be placed inside typeset equations}',
  720                      'HTML_tth' => '\\begin{rawhtml} '. $answer_rule.'\\end{rawhtml}',
  721                      'HTML_dpng' => '\fbox{Answer boxes cannot be placed inside typeset equations}',
  722                      'HTML'     => $answer_rule
  723                    );
  724 
  725     $out;
  726 }
  727 # still needs some cleanup.
  728 sub NAMED_TEX_ANS_RULE {
  729     my $name = shift;
  730   my $len = shift;
  731   $len    = 20 unless $len ;
  732     my $answer_rule = NAMED_ANS_RULE($name ,$len);  # we don't want to create three answer rules in different modes.
  733     my $out = MODES(
  734                      'TeX' => $answer_rule,
  735                      'Latex2HTML' => '\\fbox{Answer boxes cannot be placed inside typeset equations}',
  736                      'HTML_tth' => '\\begin{rawhtml} '. $answer_rule.'\\end{rawhtml}',
  737                      'HTML_dpng' => '\\fbox{Answer boxes cannot be placed inside typeset equations}',
  738                      'HTML'     => $answer_rule
  739                    );
  740 
  741     $out;
  742 }
  743 sub NAMED_TEX_ANS_RULE_EXTENSION {
  744   my $name = shift;
  745   my $len = shift;
  746   $len    = 20 unless $len ;
  747     my $answer_rule = NAMED_ANS_RULE_EXTENSION($name ,$len);  # we don't want to create three answer rules in different modes.
  748     my $out = MODES(
  749                      'TeX' => $answer_rule,
  750                      'Latex2HTML' => '\fbox{Answer boxes cannot be placed inside typeset equations}',
  751                      'HTML_tth' => '\\begin{rawhtml} '. $answer_rule.'\\end{rawhtml}',
  752                      'HTML_dpng' => '\fbox{Answer boxes cannot be placed inside typeset equations}',
  753                      'HTML'     => $answer_rule
  754                    );
  755 
  756     $out;
  757 }
  758 sub ans_box {
  759   my $row = shift;
  760   my $col =shift;
  761   $row = 5 unless $row;
  762   $col = 80 unless $col;
  763   my $name = NEW_ANS_NAME(inc_ans_rule_count());
  764   NAMED_ANS_BOX($name ,$row,$col);
  765 }
  766 
  767 #this is legacy code; use ans_checkbox instead
  768 sub checkbox {
  769   my %options = @_;
  770   qq!<INPUT TYPE="checkbox" NAME="$options{'-name'}" VALUE="$options{'-value'}">$options{'-label'}!
  771 }
  772 
  773 
  774 sub NAMED_POP_UP_LIST {
  775     my $name = shift;
  776   my @list = @_;
  777   if(ref($list[0]) eq 'ARRAY') {
  778     my @list1 = @{$list[0]};
  779     @list = map { $_ => $_ } @list1;
  780   }
  781   $name = RECORD_ANS_NAME($name);   # record answer name
  782     my $answer_value = '';
  783   $answer_value = ${$inputs_ref}{$name} if defined(${$inputs_ref}{$name});
  784   my $out = "";
  785   if ($displayMode eq 'HTML' or $displayMode eq 'HTML_tth' or
  786             $displayMode eq 'HTML_dpng' or $displayMode eq 'HTML_img' or $displayMode eq 'HTML_jsMath' or
  787       $displayMode eq 'HTML_asciimath' or $displayMode eq 'HTML_LaTeXMathML') {
  788     $out = qq!<SELECT NAME = "$name" SIZE=1> \n!;
  789     my $i;
  790     foreach ($i=0; $i< @list; $i=$i+2) {
  791       my $select_flag = ($list[$i] eq $answer_value) ? "SELECTED" : "";
  792       $out .= qq!<OPTION $select_flag VALUE ="$list[$i]" > $list[$i+1]  </OPTION>\n!;
  793     };
  794     $out .= " </SELECT>\n";
  795   } elsif ( $displayMode eq "Latex2HTML") {
  796     $out = qq! \\begin{rawhtml}<SELECT NAME = "$name" SIZE=1> \\end{rawhtml} \n !;
  797     my $i;
  798     foreach ($i=0; $i< @list; $i=$i+2) {
  799       my $select_flag = ($list[$i] eq $answer_value) ? "SELECTED" : "";
  800       $out .= qq!\\begin{rawhtml}<OPTION $select_flag VALUE ="$list[$i]" > $list[$i+1]  </OPTION>\\end{rawhtml}\n!;
  801     };
  802     $out .= " \\begin{rawhtml}</SELECT>\\end{rawhtml}\n";
  803   } elsif ( $displayMode eq "TeX") {
  804       $out .= "\\fbox{?}";
  805   }
  806 
  807 }
  808 
  809 sub pop_up_list {
  810   my @list = @_;
  811   my $name = NEW_ANS_NAME(inc_ans_rule_count());  # get new answer name
  812   NAMED_POP_UP_LIST($name, @list);
  813 }
  814 
  815 
  816 
  817 =head5  answer_matrix
  818 
  819     Usage   \[ \{   answer_matrix(rows,columns,width_of_ans_rule, @options) \} \]
  820 
  821     Creates an array of answer blanks and passes it to display_matrix which returns
  822     text which represents the matrix in TeX format used in math display mode. Answers
  823     are then passed back to whatever answer evaluators you write at the end of the problem.
  824     (note, if you have an m x n matrix, you will need mn answer evaluators, and they will be
  825     returned to the evaluaters starting in the top left hand corner and proceed to the left
  826     and then at the end moving down one row, just as you would read them.)
  827 
  828     The options are passed on to display_matrix.
  829 
  830 
  831 =cut
  832 
  833 
  834 sub answer_matrix{
  835   my $m = shift;
  836   my $n = shift;
  837   my $width = shift;
  838   my @options = @_;
  839   my @array=();
  840   for( my $i = 0; $i < $m; $i+=1)
  841   {
  842     my @row_array = ();
  843 
  844     for( my $i = 0; $i < $n; $i+=1)
  845     {
  846       push @row_array,  ans_rule($width);
  847     }
  848     my $r_row_array = \@row_array;
  849     push @array,  $r_row_array;
  850   }
  851   # display_matrix hasn't been loaded into the cache safe compartment
  852   # so we need to refer to the subroutine in this way to make
  853   # sure that main is defined correctly.
  854   my $ra_local_display_matrix=PG_restricted_eval(q!\&main::display_matrix!);
  855   &$ra_local_display_matrix( \@array, @options );
  856 
  857 }
  858 
  859 sub NAMED_ANS_ARRAY_EXTENSION{
  860 
  861   my $name = shift;
  862   my $col = shift;
  863   $col = 20 unless $col;
  864   my $answer_value = '';
  865 
  866   $answer_value = ${$inputs_ref}{$name} if    defined(${$inputs_ref}{$name});
  867   if ($answer_value =~ /\0/ ) {
  868     my @answers = split("\0", $answer_value);
  869     $answer_value = shift(@answers);
  870     $answer_value= '' unless defined($answer_value);
  871   } elsif (ref($answer_value) eq 'ARRAY') {
  872     my @answers = @{ $answer_value};
  873       $answer_value = shift(@answers);
  874         $answer_value= '' unless defined($answer_value);
  875   }
  876 
  877   $answer_value =~ tr/\\$@`//d;   #`## make sure student answers can not be interpolated by e.g. EV3
  878   MODES(
  879     TeX => "\\mbox{\\parbox[t]{10pt}{\\hrulefill}}\\hrulefill\\quad ",
  880     Latex2HTML => qq!\\begin{rawhtml}\n<INPUT TYPE=TEXT SIZE=$col NAME=\"$name\" VALUE = \"\">\n\\end{rawhtml}\n!,
  881     HTML => "<INPUT TYPE=TEXT SIZE=$col NAME=\"$name\" VALUE = \"$answer_value\">\n"
  882   );
  883 }
  884 
  885 sub ans_array{
  886   my $m = shift;
  887   my $n = shift;
  888   my $col = shift;
  889   $col = 20 unless $col;
  890   my $num = inc_ans_rule_count() ;
  891   my $name = NEW_ANS_ARRAY_NAME($num,0,0);
  892   my @options = @_;
  893   my @array=();
  894   my $string;
  895   my $answer_value = "";
  896 
  897   $array[0][0] =   NAMED_ANS_RULE($name,$col);
  898 
  899   for( my $i = 1; $i < $n; $i+=1)
  900   {
  901     $name = NEW_ANS_ARRAY_NAME_EXTENSION($num,0,$i);
  902     $array[0][$i] =   NAMED_ANS_ARRAY_EXTENSION($name,$col);
  903 
  904   }
  905 
  906   for( my $j = 1; $j < $m; $j+=1 ){
  907 
  908     for( my $i = 0; $i < $n; $i+=1)
  909     {
  910       $name = NEW_ANS_ARRAY_NAME_EXTENSION($num,$j,$i);
  911       $array[$j][$i] =  NAMED_ANS_ARRAY_EXTENSION($name,$col);
  912 
  913     }
  914 
  915   }
  916   my $ra_local_display_matrix=PG_restricted_eval(q!\&main::display_matrix!);
  917   &$ra_local_display_matrix( \@array, @options );
  918 
  919 }
  920 
  921 sub ans_array_extension{
  922   my $m = shift;
  923   my $n = shift;
  924   my $col = shift;
  925   $col = 20 unless $col;
  926   my $num = PG_restricted_eval(q!$main::ans_rule_count!);
  927   my @options = @_;
  928   my $name;
  929   my @array=();
  930   my $string;
  931   my $answer_value = "";
  932 
  933   for( my $j = 0; $j < $m; $j+=1 ){
  934 
  935     for( my $i = 0; $i < $n; $i+=1)
  936     {
  937       $name = NEW_ANS_ARRAY_NAME_EXTENSION($num,$j,$i);
  938       $array[$j][$i] =  NAMED_ANS_ARRAY_EXTENSION($name,$col);
  939 
  940     }
  941 
  942   }
  943   my $ra_local_display_matrix=PG_restricted_eval(q!\&main::display_matrix!);
  944   &$ra_local_display_matrix( \@array, @options );
  945 
  946 }
  947 
  948 
  949 # end answer blank macros
  950 
  951 =head2 Hints and solutions macros
  952 
  953   solution('text','text2',...);
  954   SOLUTION('text','text2',...);   # equivalent to TEXT(solution(...));
  955 
  956   hint('text', 'text2', ...);
  957   HINT('text', 'text2',...);      # equivalent to TEXT("$BR$HINT" . hint(@_) . "$BR") if hint(@_);
  958 
  959 Solution prints its concatenated input when the check box named 'ShowSol' is set and
  960 the time is after the answer date.  The check box 'ShowSol' is visible only after the
  961 answer date or when the problem is viewed by a professor.
  962 
  963 $main::envir{'displaySolutionsQ'} is set to 1 when a solution is to be displayed.
  964 
  965 Hints are shown only after the number of attempts is greater than $:showHint
  966 ($main::showHint defaults to 1) and the check box named 'ShowHint' is set. The check box
  967 'ShowHint' is visible only after the number of attempts is greater than $main::showHint.
  968 
  969 $main::envir{'displayHintsQ'} is set to 1 when a hint is to be displayed.
  970 
  971 
  972 =cut
  973 
  974 
  975 
  976 #   solution prints its input when $displaySolutionsQ is set.
  977 #   use as TEXT(solution("blah, blah");
  978 #   \$solutionExists
  979 #   is passed to processProblem which displays a "show Solution" button
  980 #   when a solution is available for viewing
  981 
  982 
  983 sub solution {
  984   my @in = @_;
  985   my $out = '';
  986   PG_restricted_eval(q!$main::solutionExists =1!);
  987   if (PG_restricted_eval(q!$main::envir{'displaySolutionsQ'}!)) {$out = join(' ',@in);}
  988     $out;
  989 }
  990 
  991 
  992 sub SOLUTION {
  993   TEXT( solution(@_)) ;
  994 }
  995 
  996 
  997 sub hint {
  998     my @in = @_;
  999   my $out = '';
 1000   my $permissionLevel = PG_restricted_eval(q!$main::envir{permissionLevel}!);
 1001   my $PRINT_FILE_NAMES_PERMISSION_LEVEL = PG_restricted_eval(q!$envir->{'PRINT_FILE_NAMES_PERMISSION_LEVEL'}!);
 1002     my $printHintForInstructor = $permissionLevel >= $PRINT_FILE_NAMES_PERMISSION_LEVEL;
 1003     my $showHint = PG_restricted_eval(q!$main::showHint!);
 1004     my $displayHint = PG_restricted_eval(q!$envir->{'displayHintsQ'}!);
 1005   PG_restricted_eval(q!$main::hintExists =1!);
 1006     PG_restricted_eval(q!$main::numOfAttempts = 0 unless defined($main::numOfAttempts);!);
 1007     my $attempts = PG_restricted_eval(q!$main::numOfAttempts!);
 1008 
 1009   if ($displayMode eq 'TeX')   {
 1010       if ($printHintForInstructor) {
 1011         $out = join(' ',@in, "$BR(Show hint after $showHint attempts. ) $BR");
 1012     } else  {
 1013       $out = '';  # do nothing since hints are not available for download for students
 1014     }
 1015   } elsif ($printHintForInstructor) {  # always print hints for instructor types
 1016     $out = join(' ',@in, "$BR(Show hint after $showHint attempts. )$BR ");
 1017   } elsif ( $displayHint  and ( $attempts > $showHint ))  {
 1018 
 1019    ## the second test above prevents a hint being shown if a doctored form is submitted
 1020 
 1021     $out = join(' ',@in);
 1022   }    # show hint
 1023 
 1024   $out ;
 1025 }
 1026 
 1027 
 1028 sub HINT {
 1029     TEXT("$BR" . hint(@_) . "$BR") if hint(@_);
 1030 }
 1031 
 1032 
 1033 
 1034 # End hints and solutions macros
 1035 #################################
 1036 
 1037 =head2 Comments to instructors
 1038 
 1039   COMMENT('text','text2',...);
 1040 
 1041 Takes the text to be lines of a comment to be shown only
 1042 in the Library Browser below the rendered problem.
 1043 
 1044 The function COMMENT stores the needed html in the variable
 1045 pgComment, which gets transfered to the flag 'comment' in PG_FLAGS.
 1046 
 1047 =cut
 1048 
 1049 # Add a comment which will display in the Library browser
 1050 #  Currently, the only output is html
 1051 
 1052 sub COMMENT {
 1053     my @in = @_;
 1054   my $out = join("$BR", @in);
 1055   my $out = '<div class=\"AuthorComment\">'.$out.'</div>';
 1056 
 1057   PG_restricted_eval(q!$main::pgComment = "!.$out.q!"!);
 1058   return('');
 1059 }
 1060 
 1061 #################################
 1062 # Produces a random number between $begin and $end with increment 1.
 1063 # You do not have to worry about integer or floating point types.
 1064 
 1065 =head2 Pseudo-random number generator
 1066 
 1067   Usage:
 1068   random(0,5,.1)      # produces a random number between 0 and 5 in increments of .1
 1069   non_zero_random(0,5,.1) # gives a non-zero random number
 1070 
 1071   list_random(2,3,5,6,7,8,10) # produces random value from the list
 1072   list_random(2,3, (5..8),10) # does the same thing
 1073 
 1074   SRAND(seed)     # resets the main random generator -- use very cautiously
 1075 
 1076 
 1077 SRAND(time) will create a different problem everytime it is called.  This makes it difficult
 1078 to check the answers :-).
 1079 
 1080 SRAND($envir->{'inputs_ref'}->{'key'} ) will create a different problem for each login session.
 1081 This is probably what is desired.
 1082 
 1083 =cut
 1084 
 1085 
 1086 sub random  {
 1087   my ($begin, $end, $incr) = @_;
 1088   $PG_random_generator->random($begin,$end,$incr);
 1089 }
 1090 
 1091 
 1092 sub non_zero_random { ##gives a non-zero random number
 1093   my (@arguments)=@_;
 1094   my $a=0;
 1095   my $i=100; #safety counter
 1096   while ($a==0 && ( 0 < $i-- ) ) {
 1097     $a=random(@arguments);
 1098   }
 1099   $a;
 1100 }
 1101 
 1102 sub list_random {
 1103         my(@li) = @_;
 1104         return $li[random(1,scalar(@li))-1];
 1105 }
 1106 
 1107 sub SRAND { # resets the main random generator -- use cautiously
 1108     my $seed = shift;
 1109   $PG_random_generator -> srand($seed);
 1110 }
 1111 
 1112 # display macros
 1113 
 1114 =head2 Display Macros
 1115 
 1116 These macros produce different output depending on the display mode being used to show
 1117 the problem on the screen, or whether the problem is being converted to TeX to produce
 1118 a hard copy output.
 1119 
 1120   MODES   ( TeX =>        "Output this in TeX mode",
 1121             HTML =>       "output this in HTML mode",
 1122             HTML_tth =>   "output this in HTML_tth mode",
 1123             HTML_dpng =>   "output this in HTML_dpng mode",
 1124             Latex2HTML => "output this in Latex2HTML mode",
 1125            )
 1126 
 1127   TEX     (tex_version, html_version) #obsolete
 1128 
 1129   M3      (tex_version, latex2html_version, html_version) #obsolete
 1130 
 1131 
 1132 
 1133 =cut
 1134 
 1135 
 1136 sub TEX {
 1137   my ($tex, $html ) = @_;
 1138   MODES(TeX => $tex, HTML => $html, HTML_tth => $html, HTML_dpng => $html);
 1139 }
 1140 
 1141 
 1142 sub M3 {
 1143   my($tex,$l2h,$html) = @_;
 1144   MODES(TeX => $tex, Latex2HTML => $l2h, HTML => $html, HTML_tth => $html, HTML_dpng => $html);
 1145 }
 1146 
 1147 # MODES() is now table driven
 1148 our %DISPLAY_MODE_FAILOVER = (
 1149   TeX              => [],
 1150   HTML             => [],
 1151   HTML_tth         => [ "HTML", ],
 1152   HTML_dpng        => [ "HTML_tth", "HTML", ],
 1153   HTML_jsMath      => [ "HTML_dpng", "HTML_tth", "HTML", ],
 1154   HTML_asciimath   => [ "HTML_dpng", "HTML_tth", "HTML", ],
 1155   HTML_LaTeXMathML => [ "HTML_dpng", "HTML_tth", "HTML", ],
 1156   # legacy modes -- these are not supported, but some problems might try to
 1157   # set the display mode to one of these values manually and some macros may
 1158   # provide rendered versions for these modes but not the one we want.
 1159   Latex2HTML  => [ "TeX", "HTML", ],
 1160   HTML_img    => [ "HTML_dpng", "HTML_tth", "HTML", ],
 1161 );
 1162 
 1163 # This replaces M3.  You can add new modes at will to this one.
 1164 sub MODES {
 1165   my %options = @_;
 1166 
 1167   # is a string supplied for the current display mode? if so, return it
 1168   return $options{$displayMode} if defined $options{$displayMode};
 1169 
 1170   # otherwise, fail over to backup modes
 1171   my @backup_modes;
 1172   if (exists $DISPLAY_MODE_FAILOVER{$displayMode}) {
 1173     @backup_modes = @{$DISPLAY_MODE_FAILOVER{$displayMode}};
 1174     foreach my $mode (@backup_modes) {
 1175       return $options{$mode} if defined $options{$mode};
 1176     }
 1177   }
 1178   die "ERROR in defining MODES: neither display mode $displayMode nor",
 1179     " any fallback modes (", join(", ", @backup_modes), ") supplied.\n";
 1180 }
 1181 
 1182 # end display macros
 1183 
 1184 
 1185 =head2  Display constants
 1186 
 1187   @ALPHABET       ALPHABET()      capital letter alphabet -- ALPHABET[0] = 'A'
 1188   $PAR        PAR()       paragraph character (\par or <p>)
 1189   $BR             BR()        line break character
 1190   $LQ         LQ()        left double quote
 1191   $RQ         RQ()        right double quote
 1192   $BM         BM()        begin math
 1193   $EM         EM()        end math
 1194   $BDM        BDM()       begin display math
 1195   $EDM        EDM()       end display math
 1196   $LTS        LTS()       strictly less than
 1197   $GTS        GTS()       strictly greater than
 1198   $LTE        LTE()       less than or equal
 1199   $GTE        GTE()       greater than or equal
 1200   $BEGIN_ONE_COLUMN BEGIN_ONE_COLUMN()  begin one-column mode
 1201   $END_ONE_COLUMN   END_ONE_COLUMN()  end one-column mode
 1202   $SOL        SOLUTION_HEADING()  solution headline
 1203   $SOLUTION     SOLUTION_HEADING()  solution headline
 1204   $HINT       HINT_HEADING()    hint headline
 1205   $US         US()        underscore character
 1206   $SPACE        SPACE()       space character (tex and latex only)
 1207   $BBOLD        BBOLD()       begin bold typeface
 1208   $EBOLD        EBOLD()       end bold typeface
 1209   $BITALIC        BITALIC()       begin italic typeface
 1210   $EITALIC        EITALIC()       end italic typeface
 1211   $BCENTER        BCENTER()       begin centered environment
 1212   $ECENTER        ECENTER()       end centered environment
 1213   $HR         HR()        horizontal rule
 1214   $LBRACE       LBRACE()      left brace
 1215   $LB         LB ()       left brace
 1216   $RBRACE       RBRACE()      right brace
 1217   $RB         RB ()       right brace
 1218   $DOLLAR       DOLLAR()      a dollar sign
 1219   $PERCENT      PERCENT()     a percent sign
 1220   $CARET        CARET()       a caret sign
 1221   $PI         PI()        the number pi
 1222   $E          E()         the number e
 1223 
 1224 =cut
 1225 
 1226 
 1227 
 1228 
 1229 
 1230 # A utility variable.  Notice that "B"=$ALPHABET[1] and
 1231 # "ABCD"=@ALPHABET[0..3].
 1232 
 1233 sub ALPHABET  {
 1234   ('A'..'ZZ')[@_];
 1235 }
 1236 
 1237 ###############################################################
 1238 # Some constants which are different in tex and in HTML
 1239 # The order of arguments is TeX, Latex2HTML, HTML
 1240 # Adopted Davide Cervone's improvements to PAR, LTS, GTS, LTE, GTE, LBRACE, RBRACE, LB, RB. 7-14-03 AKP
 1241 sub PAR { MODES( TeX => '\\par ', Latex2HTML => '\\begin{rawhtml}<P>\\end{rawhtml}', HTML => '<P>'); };
 1242 #sub BR { MODES( TeX => '\\par\\noindent ', Latex2HTML => '\\begin{rawhtml}<BR>\\end{rawhtml}', HTML => '<BR>'); };
 1243 # Alternate definition of BR which is slightly more flexible and gives more white space in printed output
 1244 # which looks better but kills more trees.
 1245 sub BR { MODES( TeX => '\\leavevmode\\\\\\relax ', Latex2HTML => '\\begin{rawhtml}<BR>\\end{rawhtml}', HTML => '<BR>'); };
 1246 sub LQ { MODES( TeX => "\\lq\\lq{}", Latex2HTML =>   '"',  HTML =>  '&quot;' ); };
 1247 sub RQ { MODES( TeX => "\\rq\\rq{}", Latex2HTML =>   '"',   HTML =>  '&quot;' ); };
 1248 sub BM { MODES(TeX => '\\(', Latex2HTML => '\\(', HTML =>  ''); };  # begin math mode
 1249 sub EM { MODES(TeX => '\\)', Latex2HTML => '\\)', HTML => ''); };  # end math mode
 1250 sub BDM { MODES(TeX => '\\[', Latex2HTML =>   '\\[', HTML =>   '<P ALIGN=CENTER>'); };  #begin displayMath mode
 1251 sub EDM { MODES(TeX => '\\]',  Latex2HTML =>  '\\]', HTML => '</P>'); };              #end displayMath mode
 1252 sub LTS { MODES(TeX => '<', Latex2HTML => '\\lt ', HTML => '&lt;', HTML_tth => '<' ); };
 1253 sub GTS { MODES(TeX => '>', Latex2HTML => '\\gt ', HTML => '&gt;', HTML_tth => '>' ); };
 1254 sub LTE { MODES(TeX => '\\le ', Latex2HTML => '\\le ', HTML => '<U>&lt;</U>', HTML_tth => '\\le ' ); };
 1255 sub GTE { MODES(TeX => '\\ge ', Latex2HTML => '\\ge ', HTML => '<U>&gt;</U>', HTML_tth => '\\ge ' ); };
 1256 sub BEGIN_ONE_COLUMN { MODES(TeX => " \\end{multicols}\n",  Latex2HTML => " ", HTML =>   " "); };
 1257 sub END_ONE_COLUMN { MODES(TeX =>
 1258               " \\begin{multicols}{2}\n\\columnwidth=\\linewidth\n",
 1259                             Latex2HTML => ' ', HTML => ' ');
 1260 
 1261 };
 1262 sub SOLUTION_HEADING { MODES( TeX => '\\par {\\bf Solution:}',
 1263                  Latex2HTML => '\\par {\\bf Solution:}',
 1264                HTML =>  '<P><B>Solution:</B>');
 1265               };
 1266 sub HINT_HEADING { MODES( TeX => "\\par {\\bf Hint:}", Latex2HTML => "\\par {\\bf Hint:}", HTML => "<P><B>Hint:</B>"); };
 1267 sub US { MODES(TeX => '\\_', Latex2HTML => '\\_', HTML => '_');};  # underscore, e.g. file${US}name
 1268 sub SPACE { MODES(TeX => '\\ ',  Latex2HTML => '\\ ', HTML => '&nbsp;');};  # force a space in latex, doesn't force extra space in html
 1269 sub BBOLD { MODES(TeX => '{\\bf ',  Latex2HTML => '{\\bf ', HTML => '<B>'); };
 1270 sub EBOLD { MODES( TeX => '}', Latex2HTML =>  '}',HTML =>  '</B>'); };
 1271 sub BITALIC { MODES(TeX => '{\\it ',  Latex2HTML => '{\\it ', HTML => '<I>'); };
 1272 sub EITALIC { MODES(TeX => '} ',  Latex2HTML => '} ', HTML => '</I>'); };
 1273 sub BCENTER { MODES(TeX => '\\begin{center} ',  Latex2HTML => ' \\begin{rawhtml} <div align="center"> \\end{rawhtml} ', HTML => '<div align="center">'); };
 1274 sub ECENTER { MODES(TeX => '\\end{center} ',  Latex2HTML => ' \\begin{rawhtml} </div> \\end{rawhtml} ', HTML => '</div>'); };
 1275 sub HR { MODES(TeX => '\\par\\hrulefill\\par ', Latex2HTML => '\\begin{rawhtml} <HR> \\end{rawhtml}', HTML =>  '<HR>'); };
 1276 sub LBRACE { MODES( TeX => '\{', Latex2HTML =>   '\\lbrace',  HTML =>  '{' , HTML_tth=> '\\lbrace' ); };
 1277 sub RBRACE { MODES( TeX => '\}', Latex2HTML =>   '\\rbrace',  HTML =>  '}' , HTML_tth=> '\\rbrace',); };
 1278 sub LB { MODES( TeX => '\{', Latex2HTML =>   '\\lbrace',  HTML =>  '{' , HTML_tth=> '\\lbrace' ); };
 1279 sub RB { MODES( TeX => '\}', Latex2HTML =>   '\\rbrace',  HTML =>  '}' , HTML_tth=> '\\rbrace',); };
 1280 sub DOLLAR { MODES( TeX => '\\$', Latex2HTML => '&#36;', HTML => '&#36;' ); };
 1281 sub PERCENT { MODES( TeX => '\\%', Latex2HTML => '\\%', HTML => '%' ); };
 1282 sub CARET { MODES( TeX => '\\verb+^+', Latex2HTML => '\\verb+^+', HTML => '^' ); };
 1283 sub PI {4*atan2(1,1);};
 1284 sub E {exp(1);};
 1285 
 1286 ###############################################################
 1287 ## Evaluation macros
 1288 
 1289 
 1290 =head2 TEXT macros
 1291 
 1292   Usage:
 1293     TEXT(@text);
 1294 
 1295 This is the simplest way to print text from a problem.  The strings in the array C<@text> are concatenated
 1296 with spaces between them and printed out in the text of the problem.  The text is not processed in any other way.
 1297 C<TEXT> is defined in PG.pl.
 1298 
 1299   Usage:
 1300     BEGIN_TEXT
 1301       text.....
 1302     END_TEXT
 1303 
 1304 This is the most common way to enter text into the problem.  All of the text between BEGIN_TEXT and END_TEXT
 1305 is processed by the C<EV3> macro described below and then printed using the C<TEXT> command.  The two key words
 1306 must appear on lines by themselves.  The preprocessing that makes this construction work is done in F<PGtranslator.pm>.
 1307 See C<EV3> below for details on the processing.
 1308 
 1309 
 1310 =cut
 1311 
 1312 =head2 Evaluation macros
 1313 
 1314 =head3 EV3
 1315 
 1316         TEXT(EV3("This is a formulat \( \int_0^5 x^2 \, dx \) ");
 1317         TEXT(EV3(@text));
 1318 
 1319     TEXT(EV3(<<'END_TEXT'));
 1320       text stuff...
 1321     END_TEXT
 1322 
 1323 
 1324 The BEGIN_TEXT/END_TEXT construction is translated into the construction above by PGtranslator.pm.  END_TEXT must appear
 1325 on a line by itself and be left justified.  (The << construction is known as a "here document" in UNIX and in PERL.)
 1326 
 1327 The single quotes around END_TEXT mean that no automatic interpolation of variables takes place in the text.
 1328 Using EV3 with strings which have been evaluated by double quotes may lead to unexpected results.
 1329 
 1330 
 1331 The evaluation macro E3 first evaluates perl code inside the braces:  C<\{  code \}>.
 1332 Any perl statment can be put inside the braces.  The
 1333 result of the evaluation (i.e. the last statement evaluated) replaces the C<\{ code \}> construction.
 1334 
 1335 Next interpolation of all variables (e.g. C<$var or @array> ) is performed.
 1336 
 1337 Then mathematical formulas in TeX are evaluated within the
 1338 C<\(  tex math mode \)> and
 1339 C<\[ tex display math mode \] >
 1340 constructions, in that order:
 1341 
 1342 =head3 FEQ
 1343 
 1344   FEQ($string);   # processes and outputs the string
 1345 
 1346 
 1347 The mathematical formulas are run through the macro C<FEQ> (Format EQuations) which performs
 1348 several substitutions (see below).
 1349 In C<HTML_tth> mode the resulting code is processed by tth to obtain an HTML version
 1350 of the formula. (In the future processing by WebEQ may be added here as another option.)
 1351 The Latex2HTML mode does nothing
 1352 at this stage; it creates the entire problem before running it through
 1353 TeX and creating the GIF images of the equations.
 1354 
 1355 The resulting string is output (and usually fed into TEXT to be printed in the problem).
 1356 
 1357   Usage:
 1358 
 1359     $string2 = FEQ($string1);
 1360 
 1361 This is a filter which is used to format equations by C<EV2> and C<EV3>, but can also be used on its own.  It is best
 1362 understood with an example.
 1363 
 1364     $string1 = "${a}x^2 + ${b}x + {$c:%.1f}"; $a = 3;, $b = -2; $c = -7.345;
 1365 
 1366 when interpolated becomes:
 1367 
 1368     $string1 = '3x^2 + -2x + {-7.345:%0.1f}
 1369 
 1370 FEQ first changes the number of decimal places displayed, so that the last term becomes -7.3 Then it removes the
 1371 extraneous plus and minus signs, so that the final result is what you want:
 1372 
 1373     $string2 = '3x^2 - 2x -7.3';
 1374 
 1375 (The %0.1f construction
 1376 is the same formatting convention used by Perl and nearly identical to the one used by the C printf statement. Some common
 1377 usage:  %0.3f 3 decimal places, fixed notation; %0.3e 3 significant figures exponential notation; %0.3g uses either fixed
 1378 or exponential notation depending on the size of the number.)
 1379 
 1380 Two additional legacy formatting constructions are also supported:
 1381 
 1382 C<!{$c:%0.3f} > will give a number with 3 decimal places and a negative
 1383 sign if the number is negative, no sign if the number is positive.  Since this is
 1384 identical to the behavior of C<{$c:%0.3f}> the use of this syntax is depricated.
 1385 
 1386 C<?{$c:%0.3f}> determines the sign and prints it
 1387 whether the number is positive or negative.  You can use this
 1388 to force an expression such as C<+5.456>.
 1389 
 1390 =head3 EV2
 1391 
 1392     TEXT(EV2(@text));
 1393 
 1394     TEXT(EV2(<<END_OF_TEXT));
 1395       text stuff...
 1396     END_OF_TEXT
 1397 
 1398 This is a precursor to EV3.  In this case the constants are interpolated first, before the evaluation of the \{ ...code...\}
 1399 construct. This can lead to unexpected results.  For example C<\{ join(" ", @text) \}> with C<@text = ("Hello","World");> becomes,
 1400 after interpolation, C<\{ join(" ",Hello World) \}> which then causes an error when evaluated because Hello is a bare word.
 1401 C<EV2> can still be useful if you allow for this, and in particular it works on double quoted strings, which lead to
 1402 unexpected results with C<EV3>. Using single quoted strings with C<EV2> may lead to unexpected results.
 1403 
 1404 The unexpected results have to do with the number of times backslashed constructions have to be escaped. It is quite messy.  For
 1405 more details get a good Perl book and then read the code. :-)
 1406 
 1407 
 1408 
 1409 
 1410 =cut
 1411 
 1412 
 1413 sub ev_substring {
 1414     my $string      = shift;
 1415   my $start_delim = shift;
 1416   my $end_delim   = shift;
 1417   my $actionRef   = shift;
 1418   my ($eval_out,$PG_eval_errors,$PG_full_error_report)=();
 1419     my $out = "";
 1420                 #
 1421                 #  DPVC -- 2001/12/07
 1422                 #     original "while ($string)" fails to process the string "0" correctly
 1423                 #
 1424     while ($string ne "") {
 1425                 #
 1426                 #  end DPVC
 1427                 #
 1428         if ($string =~ /\Q$start_delim\E/s) {
 1429        #print "$start_delim $end_delim evaluating_substring=$string<BR>";
 1430         $string =~ s/^(.*?)\Q$start_delim\E//s;  # get string up to next \{ ---treats string as a single line, ignoring returns
 1431         $out .= $1;
 1432        #print "$start_delim $end_delim substring_out=$out<BR>";
 1433         $string =~ s/^(.*?)\Q$end_delim\E//s;  # get perl code up to \} ---treats string as a single line,  ignoring returns
 1434            #print "$start_delim $end_delim evaluate_string=$1<BR>";
 1435         ($eval_out,$PG_eval_errors,$PG_full_error_report) = &$actionRef($1);
 1436         $eval_out = "$start_delim $eval_out $end_delim" if $PG_full_error_report;
 1437         $out = $out . $eval_out;
 1438        #print "$start_delim $end_delim new substring_out=$out<BR><p><BR>";
 1439         $out .="$PAR ERROR $0 in ev_substring, PGbasicmacros.pl:$PAR <PRE>  $@ </PRE>$PAR" if $@;
 1440         }
 1441       else {
 1442         $out .= $string;  # flush the last part of the string
 1443         last;
 1444         }
 1445 
 1446       }
 1447   $out;
 1448 }
 1449 sub  safe_ev {
 1450     my ($out,$PG_eval_errors,$PG_full_error_report) = &old_safe_ev;   # process input by old_safe_ev first
 1451     $out =~s/\\/\\\\/g;   # protect any new backslashes introduced.
 1452   ($out,$PG_eval_errors,$PG_full_error_report)
 1453 }
 1454 
 1455 sub  old_safe_ev {
 1456     my $in = shift;
 1457     my   ($out,$PG_eval_errors,$PG_full_error_report) = PG_restricted_eval("$in;");
 1458     # the addition of the ; seems to provide better error reporting
 1459     if ($PG_eval_errors) {
 1460       my @errorLines = split("\n",$PG_eval_errors);
 1461     #$out = "<PRE>$PAR % ERROR in $0:old_safe_ev, PGbasicmacros.pl: $PAR % There is an error occuring inside evaluation brackets \\{ ...code... \\} $BR % somewhere in an EV2 or EV3 or BEGIN_TEXT block. $BR % Code evaluated:$BR $in $BR % $BR % $errorLines[0]\n % $errorLines[1]$BR % $BR % $BR </PRE> ";
 1462     warn " ERROR in old_safe_ev, PGbasicmacros.pl: <PRE>
 1463      ## There is an error occuring inside evaluation brackets \\{ ...code... \\}
 1464      ## somewhere in an EV2 or EV3 or BEGIN_TEXT block.
 1465      ## Code evaluated:
 1466      ## $in
 1467      ##" .join("\n     ", @errorLines). "
 1468      ##</PRE>$BR
 1469      ";
 1470      $out ="$PAR $BBOLD  $in $EBOLD $PAR";
 1471 
 1472 
 1473   }
 1474 
 1475   ($out,$PG_eval_errors,$PG_full_error_report);
 1476 }
 1477 
 1478 sub FEQ   {    # Format EQuations
 1479   my $in = shift;
 1480    # formatting numbers -- the ?{} and !{} constructions
 1481   $in =~s/\?\s*\{([.\-\$\w\d]+):?([%.\da-z]*)\}/${ \( &sspf($1,$2) )}/g;
 1482   $in =~s/\!\s*\{([.\-\$\w\d]+):?([%.\da-z]*)\}/${ \( &spf($1,$2) )}/g;
 1483 
 1484   # more formatting numbers -- {number:format} constructions
 1485   $in =~ s/\{(\s*[\+\-\d\.]+[eE]*[\+\-]*\d*):(\%\d*.\d*\w)}/${ \( &spf($1,$2) )}/g;
 1486   $in =~ s/\+\s*\-/ - /g;
 1487   $in =~ s/\-\s*\+/ - /g;
 1488   $in =~ s/\+\s*\+/ + /g;
 1489   $in =~ s/\-\s*\-/ + /g;
 1490   $in;
 1491 }
 1492 
 1493 #sub math_ev3 {
 1494 # my $in = shift; #print "in=$in<BR>";
 1495 # my ($out,$PG_eval_errors,$PG_full_error_report);
 1496 # $in = FEQ($in);
 1497 # $in =~ s/%/\\%/g;   #  % causes trouble in TeX and HTML_tth it usually (always?) indicates an error, not comment
 1498 # return("$BM $in $EM") unless ($displayMode eq 'HTML_tth');
 1499 # $in = "\\(" . $in . "\\)";
 1500 # $out = tth($in);
 1501 # ($out,$PG_eval_errors,$PG_full_error_report);
 1502 #
 1503 #}
 1504 #
 1505 #sub display_math_ev3 {
 1506 # my $in = shift; #print "in=$in<BR>";
 1507 # my ($out,$PG_eval_errors,$PG_full_error_report);
 1508 # $in = FEQ($in);
 1509 # $in =~ s/%/\\%/g;
 1510 # return("$main::BDM $in $main::EDM") unless $displayMode eq 'HTML_tth' ;
 1511 # $in = "\\[" . $in . "\\]";
 1512 # $out =tth($in);
 1513 # ($out,$PG_eval_errors,$PG_full_error_report);
 1514 #}
 1515 
 1516 sub math_ev3 {
 1517   my $in = shift;
 1518   return general_math_ev3($in, "inline");
 1519 }
 1520 
 1521 sub display_math_ev3 {
 1522   my $in = shift;
 1523   return general_math_ev3($in, "display");
 1524 }
 1525 
 1526 sub general_math_ev3 {
 1527   my $in = shift;
 1528   my $mode = shift || "inline";
 1529 
 1530   $in = FEQ($in); # Format EQuations
 1531   $in =~ s/%/\\%/g; # avoid % becoming TeX comments
 1532 
 1533   ## remove leading and trailing spaces so that HTML mode will
 1534   ## not include unwanted spaces as per Davide Cervone.
 1535   $in =~ s/^\s+//;
 1536   $in =~ s/\s+$//;
 1537   ## If it ends with a backslash, there should be another space
 1538   ## at the end
 1539   if($in =~ /\\$/) { $in .= ' ';}
 1540 
 1541   # some modes want the delimiters, some don't
 1542   my $in_delim = $mode eq "inline"
 1543     ? "\\($in\\)"
 1544     : "\\[$in\\]";
 1545 
 1546   my $out;
 1547   if($displayMode eq "HTML_tth") {
 1548     $out = tth($in_delim);
 1549     ## remove leading and trailing spaces as per Davide Cervone.
 1550     $out =~ s/^\s+//;
 1551     $out =~ s/\s+$//;
 1552   } elsif ($displayMode eq "HTML_dpng") {
 1553     # for jj's version of ImageGenerator
 1554     $out = $envir->{'imagegen'}->add($in_delim);
 1555     # for my version of ImageGenerator
 1556     #$out = $envir->{'imagegen'}->add($in, $mode);
 1557   } elsif ($displayMode eq "HTML_img") {
 1558     $out = math2img($in, $mode);
 1559   } elsif ($displayMode eq "HTML_jsMath") {
 1560     $in =~ s/</&lt;/g; $in =~ s/>/&gt;/g;
 1561     $out = '<SPAN CLASS="math">'.$in.'</SPAN>' if $mode eq "inline";
 1562     $out = '<DIV CLASS="math">'.$in.'</DIV>' if $mode eq "display";
 1563   } elsif ($displayMode eq "HTML_asciimath") {
 1564     $out = "`$in`" if $mode eq "inline";
 1565     $out = '<DIV ALIGN="CENTER">`'.$in.'`</DIV>' if $mode eq "display";
 1566   } elsif ($displayMode eq "HTML_LaTeXMathML") {
 1567     $in = '{'.$in.'}';
 1568     $in =~ s/</\\lt/g; $in =~ s/>/\\gt/g;
 1569     $in =~ s/\{\s*(\\(display|text|script|scriptscript)style)/$1\{/g;
 1570     $out = '$$'.$in.'$$' if $mode eq "inline";
 1571     $out = '<DIV ALIGN="CENTER">$$\displaystyle{'.$in.'}$$</DIV>' if $mode eq "display";
 1572   } else {
 1573     $out = "\\($in\\)" if $mode eq "inline";
 1574     $out = "\\[$in\\]" if $mode eq "display";
 1575   }
 1576   return $out;
 1577 }
 1578 
 1579 sub EV2 {
 1580   my $string = join(" ",@_);
 1581   # evaluate code inside of \{  \}  (no nesting allowed)
 1582     $string = ev_substring($string,"\\{","\\}",\&old_safe_ev);
 1583     $string = ev_substring($string,"\\<","\\>",\&old_safe_ev);
 1584   $string = ev_substring($string,"\\(","\\)",\&math_ev3);
 1585   $string = ev_substring($string,"\\[","\\]",\&display_math_ev3);
 1586   # macros for displaying math
 1587   $string =~ s/\\\(/$BM/g;
 1588   $string =~ s/\\\)/$EM/g;
 1589   $string =~ s/\\\[/$BDM/g;
 1590   $string =~ s/\\\]/$EDM/g;
 1591   $string;
 1592 }
 1593 
 1594 sub EV3{
 1595   my $string = join(" ",@_);
 1596   # evaluate code inside of \{  \}  (no nesting allowed)
 1597     $string = ev_substring($string,"\\\\{","\\\\}",\&safe_ev);  # handles \{ \} in single quoted strings of PG files
 1598   # interpolate variables
 1599   my ($evaluated_string,$PG_eval_errors,$PG_full_errors) = PG_restricted_eval("<<END_OF_EVALUATION_STRING\n$string\nEND_OF_EVALUATION_STRING\n");
 1600   if ($PG_eval_errors) {
 1601       my @errorLines = split("\n",$PG_eval_errors);
 1602       $string =~ s/</&lt;/g; $string =~ s/>/&gt;/g;
 1603     $evaluated_string = "<PRE>$PAR % ERROR in $0:EV3, PGbasicmacros.pl: $PAR % There is an error occuring in the following code:$BR $string $BR % $BR % $errorLines[0]\n % $errorLines[1]$BR % $BR % $BR </PRE> ";
 1604     $@="";
 1605   }
 1606   $string = $evaluated_string;
 1607   $string = ev_substring($string,"\\(","\\)",\&math_ev3);
 1608     $string = ev_substring($string,"\\[","\\]",\&display_math_ev3);
 1609   $string;
 1610 }
 1611 
 1612 sub EV4{
 1613     if ($displayMode eq "HTML_dpng") {
 1614         my $string = join(" ",@_);
 1615         my ($evaluated_string,$PG_eval_errors,$PG_full_errors) = PG_restricted_eval("<<END_OF_EVALUATION_STRING\n$string\nEND_OF_EVALUATION_STRING\n");
 1616         if ($PG_eval_errors) {
 1617             my @errorLines = split("\n",$PG_eval_errors);
 1618             $string =~ s/</&lt;/g; $string =~ s/>/&gt;/g;
 1619             $evaluated_string = "<PRE>$PAR % ERROR in $0:EV3, PGbasicmacros.pl:".
 1620       "$PAR % There is an error occuring in the following code:$BR ".
 1621       "$string $BR % $BR % $errorLines[0]\n % $errorLines[1]$BR ".
 1622       "% $BR % $BR </PRE> ";
 1623         }
 1624         $string = $evaluated_string;
 1625         $string = $envir{'imagegen'}->add($string);
 1626         $string;
 1627     } else {
 1628       EV3(@_);
 1629     }
 1630 }
 1631 
 1632 =head3 EV3P
 1633 
 1634   ######################################################################
 1635   #
 1636   #  New version of EV3 that allows `...` and ``...`` to insert TeX produced
 1637   #  by the new Parser (in math and display modes).
 1638   #
 1639   #  Format:  EV3P(string,...);
 1640   #           EV3P({options},string,...);
 1641   #
 1642   #           `x^2/5` will become \(\frac{x^2}{5}\) and then rendered for hardcopy or screen output
 1643   #
 1644   #  where options can include:
 1645   #
 1646   #    processCommands => 0 or 1     Indicates if the student's answer will
 1647   #                                  be allowed to process \{...\}.
 1648   #                                    Default: 1
 1649   #
 1650   #    processVariables => 0 1       Indicates whether variable substitution
 1651   #                                  should be performed on the student's
 1652   #                                  answer.
 1653   #                                    Default: 1
 1654   #
 1655   #    processMath => 0 or 1         Indicates whether \(...\), \[...\],
 1656   #                                  `...` and ``...`` will be processed
 1657   #                                  in the student's answer.
 1658   #                                    Default: 1
 1659   #
 1660   #    processParser => 0 or 1       Indicates if `...` and ``...`` should
 1661   #                                  be processed when math is being
 1662   #                                  processed.
 1663   #                                    Default: 1
 1664   #
 1665   #    fixDollars => 0 or 1          Specifies whether dollar signs not followed
 1666   #                                  by a letter should be replaced by ${DOLLAR}
 1667   #                                  prior to variable substitution (to prevent
 1668   #                                  accidental substitution of strange Perl
 1669   #                                  values).
 1670   #                                    Default: 1
 1671   #
 1672 
 1673 =cut
 1674 
 1675 sub EV3P {
 1676   my $option_ref = {}; $option_ref = shift if ref($_[0]) eq 'HASH';
 1677   my %options = (
 1678     processCommands => 1,
 1679     processVariables => 1,
 1680     processParser => 1,
 1681     processMath => 1,
 1682     fixDollars => 1,
 1683     %{$option_ref},
 1684   );
 1685   my $string = join(" ",@_);
 1686   $string = ev_substring($string,"\\\\{","\\\\}",\&safe_ev) if $options{processCommands};
 1687   if ($options{processVariables}) {
 1688     my $eval_string = $string;
 1689     $eval_string =~ s/\$(?![a-z\{])/\${DOLLAR}/gi if $options{fixDollars};
 1690     my ($evaluated_string,$PG_eval_errors,$PG_full_errors) =
 1691       PG_restricted_eval("<<END_OF_EVALUATION_STRING\n$eval_string\nEND_OF_EVALUATION_STRING\n");
 1692     if ($PG_eval_errors) {
 1693       my $error = (split("\n",$PG_eval_errors))[0]; $error =~ s/at \(eval.*//gs;
 1694       $string =~ s/&/&amp;/g; $string =~ s/</&lt;/g; $string =~ s/>/&gt;/g;
 1695       $evaluated_string = $BBOLD."(Error: $error in '$string')".$EBOLD;
 1696     }
 1697     $string = $evaluated_string;
 1698   }
 1699   if ($options{processMath}) {
 1700     $string = EV3P_parser($string) if $options{processParser};
 1701     $string = ev_substring($string,"\\(","\\)",\&math_ev3);
 1702     $string = ev_substring($string,"\\[","\\]",\&display_math_ev3);
 1703   }
 1704   return $string;
 1705 }
 1706 
 1707 #
 1708 #  Look through a string for ``...`` or `...` and use
 1709 #  the parser to produce TeX code for the specified mathematics.
 1710 #  ``...`` does display math, `...` does in-line math.  They
 1711 #  can also be used within math mode already, in which case they
 1712 #  use whatever mode is already in effect.
 1713 #
 1714 sub EV3P_parser {
 1715   my $string = shift;
 1716   return $string unless $string =~ m/`/;
 1717   my $start = ''; my %end = ('\('=>'\)','\['=>'\]');
 1718   my @parts = split(/(``.*?``\*?|`.+?`\*?|(?:\\[()\[\]]))/s,$string);
 1719   foreach my $part (@parts) {
 1720     if ($part =~ m/^(``?)(.*)\1(\*?)$/s) {
 1721       my ($delim,$math,$star) = ($1,$2,$3);
 1722       my $f = Parser::Formula($math);
 1723       if (defined($f)) {
 1724         $f = $f->reduce if $star;
 1725   $part = $f->TeX;
 1726   $part = ($delim eq '`' ? '\('.$part.'\)': '\['.$part.'\]') if (!$start);
 1727       } else {
 1728   ## FIXME:  use context->{error}{ref} to highlight error in $math.
 1729   $part = $BBOLD."(Error: $$Value::context->{error}{message} '$math')".$EBOLD;
 1730   $part = $end{$start}." ".$part." ".$start if $start;
 1731       }
 1732     }
 1733     elsif ($start) {$start = '' if $part eq $end{$start}}
 1734     elsif ($end{$part}) {$start = $part}
 1735   }
 1736   return join('',@parts);
 1737 }
 1738 
 1739 
 1740 =head2 Formatting macros
 1741 
 1742   beginproblem()  # generates text listing number and the point value of
 1743                   # the problem. It will also print the file name containing
 1744                   # the problem for users listed in the PRINT_FILE_NAMES_FOR PG_environment
 1745                   # variable.
 1746   OL(@array)      # formats the array as an Ordered List ( <OL> </OL> ) enumerated by letters.
 1747 
 1748   htmlLink($url, $text)
 1749                   # Places a reference to the URL with the specified text in the problem.
 1750                   # A common usage is \{ htmlLink(alias('prob1_help.html') \}, 'for help')
 1751                   # where alias finds the full address of the prob1_help.html file in the same directory
 1752                   # as the problem file
 1753   appletLink( { name => "xFunctions",
 1754                 codebase => '',    # use this to specify the complete url
 1755                                    # otherwise libraries specified in global.conf are searched
 1756                 archive  => 'xFunctions.zip', # name the archive containing code (.jar files go here also)
 1757                 code     => 'xFunctionsLauncher.class',
 1758                 width    => 100,
 1759                 height   => 14,
 1760                 params   => { param1 =>value1, param2 => value2},
 1761               }
 1762             );
 1763   helpLink()     allows site specific help specified in global.conf or course.conf
 1764                  the parameter localHelpURL  must be defined in the environment
 1765                  currently works only for 'interval notation' and 'units'
 1766                  NEEDS REFINEMENT
 1767 
 1768   ########################
 1769                 deprecated coding method
 1770           appletLink  ($url, $parameters)
 1771                   # For example
 1772                   # appletLink(q!  archive="http: //webwork.math.rochester.edu/gage/xFunctions/xFunctions.zip"
 1773                                   code="xFunctionsLauncher.class"  width=100 height=14!,
 1774                   " parameter text goes here")
 1775                   # will link to xFunctions.
 1776 
 1777   low level:
 1778 
 1779   spf($number, $format)   # prints the number with the given format
 1780   sspf($number, $format)  # prints the number with the given format, always including a sign.
 1781   nicestring($coefficients, $terms) # print a linear combinations of terms using coefficients
 1782   nicestring($coefficients) # uses the coefficients to make a polynomial
 1783       # For example
 1784       # nicestring([1,-2, 0]) produces 'x^2-2x'
 1785       # nicestring([2,0,-1],['', 't', 't^2']) produces '2-t^2'
 1786   protect_underbar($string) # protects the underbar (class_name) in strings which may have to pass through TeX.
 1787 
 1788 =cut
 1789 
 1790 sub beginproblem {
 1791   my $out = "";
 1792   my $problemValue = $envir->{problemValue};
 1793   my $fileName     = $envir->{fileName};
 1794   my $probNum      = $envir->{probNum};
 1795     my $TeXFileName = protect_underbar($envir->{fileName});
 1796     my $l2hFileName = protect_underbar($envir->{fileName});
 1797   my %inlist;
 1798   my $points ='pts';
 1799 
 1800   $points = 'pt' if $problemValue == 1;
 1801   ##    Prepare header for the problem
 1802   grep($inlist{$_}++,@{ $envir->{'PRINT_FILE_NAMES_FOR'} });
 1803   my $permissionLevel = $envir->{permissionLevel};
 1804   my $PRINT_FILE_NAMES_PERMISSION_LEVEL = $envir->{'PRINT_FILE_NAMES_PERMISSION_LEVEL'};
 1805   my $studentLogin = $envir->{studentLogin};
 1806   my $print_path_name_flag =
 1807       (defined($permissionLevel) && defined($PRINT_FILE_NAMES_PERMISSION_LEVEL) && $permissionLevel >= $PRINT_FILE_NAMES_PERMISSION_LEVEL)
 1808        || ( defined($inlist{ $studentLogin }) and ( $inlist{ $studentLogin }>0 )  ) ;
 1809 
 1810   if ( $print_path_name_flag ) {
 1811     $out = &M3("{\\bf ${probNum}. {\\footnotesize ($problemValue $points) $TeXFileName}}\\newline ",
 1812     " \\begin{rawhtml} ($problemValue $points) <B>$l2hFileName</B><BR>\\end{rawhtml}",
 1813      "($problemValue $points) <B>$fileName</B><BR>"
 1814        ) if ($problemValue ne "");
 1815   } else {
 1816     $out = &M3("{\\bf ${probNum}.} ($problemValue $points) ",
 1817     "($problemValue $points) ",
 1818      "($problemValue $points) "
 1819        ) if ($problemValue ne "");
 1820   }
 1821   $out .= MODES(%{main::PG_restricted_eval(q!$main::problemPreamble!)});
 1822   $out;
 1823 
 1824 }
 1825 
 1826 sub nicestring {
 1827     my($thingy) = shift;
 1828     my(@coefs) = @{$thingy};
 1829     my $n = scalar(@coefs);
 1830     $thingy = shift;
 1831     my(@others);
 1832     if(defined($thingy)) {
 1833   @others = @{$thingy};
 1834     } else {
 1835   my($j);
 1836   for $j (1..($n-2)) {
 1837       $others[$j-1] = "x^".($n-$j);
 1838   }
 1839   if($n>=2) { $others[$n-2] = "x";}
 1840   $others[$n-1] = "";
 1841     }
 1842     my($j, $k)=(0,0);
 1843     while(($k<$n) && ($coefs[$k]==0)) {$k++;}
 1844     if($k==$n) {return("0");}
 1845     my $ans;
 1846     if($coefs[$k]==1) {$ans = ($others[$k]) ? "$others[$k]" : "1";}
 1847     elsif($coefs[$k]== -1) {$ans =  ($others[$k]) ? "- $others[$k]" : "-1"}
 1848     else { $ans = "$coefs[$k] $others[$k]";}
 1849     $k++;
 1850     for $j ($k..($n-1)) {
 1851   if($coefs[$j] != 0) {
 1852       if($coefs[$j] == 1) {
 1853     $ans .= ($others[$j]) ? "+ $others[$j]" : "+ 1";
 1854       } elsif($coefs[$j] == -1) {
 1855     $ans .= ($others[$j]) ? "- $others[$j]" : "-1";
 1856       } else {
 1857     $ans .= "+ $coefs[$j] $others[$j]";
 1858       }
 1859   }
 1860     }
 1861     return($ans);
 1862 }
 1863 
 1864 # kludge to clean up path names
 1865             ## allow underscore character in set and section names and also allows line breaks at /
 1866 sub protect_underbar {
 1867     my $in = shift;
 1868     if ($displayMode eq 'TeX')  {
 1869 
 1870         $in =~ s|_|\\\_|g;
 1871         $in =~ s|/|\\\-/|g;  # allows an optional hyphenation of the path (in tex)
 1872     }
 1873     $in;
 1874 }
 1875 
 1876 
 1877 # An example of a macro which prints out a list (with letters)
 1878 sub OL {
 1879   my(@array) = @_;
 1880   my $i = 0;
 1881   my @alpha = ('A'..'Z', 'AA'..'ZZ');
 1882   my $letter;
 1883   my  $out=   &M3(
 1884           "\\begin{enumerate}\n",
 1885           " \\begin{rawhtml} <OL TYPE=\"A\" VALUE=\"1\"> \\end{rawhtml} ",
 1886           # kludge to fix IE/CSS problem
 1887           #"<OL TYPE=\"A\" VALUE=\"1\">\n"
 1888           "<BLOCKQUOTE>\n"
 1889           ) ;
 1890   my $elem;
 1891   foreach $elem (@array) {
 1892     $letter = shift @alpha;
 1893                 $out .= MODES(
 1894                         TeX=>   "\\item[$ALPHABET[$i].] $elem\n",
 1895                         Latex2HTML=>    " \\begin{rawhtml} <LI> \\end{rawhtml} $elem  ",
 1896                         #HTML=>  "<LI> $elem\n",
 1897                         HTML=>  "<br /> <b>$letter.</b> $elem\n",
 1898                         #HTML_dpng=>     "<LI> $elem <br /> <br /> \n"
 1899                         HTML_dpng=>     "<br /> <b>$letter.</b> $elem \n"
 1900                                         );
 1901     $i++;
 1902   }
 1903   $out .= &M3(
 1904         "\\end{enumerate}\n",
 1905         " \\begin{rawhtml} </OL>\n \\end{rawhtml} ",
 1906         #"</OL>\n"
 1907         "</BLOCKQUOTE>\n"
 1908         ) ;
 1909 }
 1910 
 1911 sub htmlLink {
 1912   my $url = shift;
 1913   my $text = shift;
 1914   my $options = shift;
 1915   $options = "" unless defined($options);
 1916   return "$BBOLD\[ broken link:  $text \] $EBOLD" unless defined($url);
 1917   M3( "{\\bf \\underline{$text}}",
 1918       "\\begin{rawhtml}<A HREF=\"$url\" $options>$text</A>\\end{rawhtml}",
 1919       "<A HREF=\"$url\" $options>$text</A>"
 1920       );
 1921 }
 1922 
 1923 
 1924 sub helpLink {
 1925   my $type1 = shift;
 1926   return "" if(not defined($envir{'localHelpURL'}));
 1927   my $type = lc($type1);
 1928   my %typeHash = (
 1929     'interval notation' => 'IntervalNotation.html',
 1930     'units' => 'Units.html',
 1931     );
 1932 
 1933   my $infoRef = $typeHash{$type};
 1934   return htmlLink( $envir{'localHelpURL'}.$infoRef, $type1,
 1935 'target="ww_help" onclick="window.open(this.href,this.target,\'width=550,height=350,scrollbars=yes,resizable=on\'); return false;"');
 1936 }
 1937 
 1938 sub appletLink {
 1939   my $url  = $_[0];
 1940   return oldAppletLink(@_) unless ref($url) ; # handle legacy where applet link completely defined
 1941   # search for applet
 1942   # get fileName of applet
 1943   my $applet       = shift;
 1944   my $options      = shift;
 1945   my $archive      = $applet ->{archive};
 1946   my $codebase     = $applet ->{codebase};
 1947   my $code         = $applet ->{code};
 1948   my $appletHeader = '';
 1949   # find location of applet
 1950     if (defined($codebase) and $codebase =~/\S/) {
 1951       # do nothing
 1952     } elsif(defined($archive) and $archive =~/\S/) {
 1953       $codebase = findAppletCodebase($archive )
 1954     } elsif (defined($code) and $code =~/\S/) {
 1955       $codebase =  findAppletCodebase($code )
 1956     } else {
 1957       warn "Must define the achive (.jar file) or code (.class file) where the applet code is to be found";
 1958       return;
 1959     }
 1960 
 1961   if ( $codebase =~/^Error/) {
 1962     warn $codebase;
 1963     return;
 1964   } else {
 1965      # we are set to include the applet
 1966   }
 1967   my $appletHeader  =  qq! archive = "$archive " codebase = "$codebase" !;
 1968   foreach my $key ('name', 'code','width','height', ) {
 1969     if ( defined($applet->{$key})   ) {
 1970       $appletHeader .= qq! $key = "!.$applet->{$key}.q!" ! ;
 1971     } else {
 1972       warn " $key is not defined for applet ".$applet->{name};
 1973       # technically name is not required, but all of the other parameters are
 1974     }
 1975   }
 1976   # add parameters to options
 1977   if (defined($applet->{params}) ) {
 1978     foreach my $key (keys %{ $applet->{params} }) {
 1979       my $value = $applet->{params}->{$key};
 1980       $options .=  qq{<PARAM NAME = "$key" VALUE = "$value" >\n};
 1981     }
 1982 
 1983 
 1984   }
 1985   MODES( TeX        => "{\\bf \\underline{APPLET}  }".$applet->{name},
 1986          Latex2HTML => "\\begin{rawhtml} <APPLET $appletHeader> $options </APPLET>\\end{rawhtml}",
 1987          HTML       => "<APPLET\n $appletHeader> \n $options \n </APPLET>",
 1988          #HTML       => qq!<OBJECT $appletHeader codetype="application/java"> $options </OBJECT>!
 1989   );
 1990 }
 1991 
 1992 sub oldAppletLink {
 1993   my $url = shift;
 1994   my $options = shift;
 1995   $options = "" unless defined($options);
 1996   MODES( TeX        => "{\\bf \\underline{APPLET}  }",
 1997          Latex2HTML => "\\begin{rawhtml} <APPLET $url> $options </APPLET>\\end{rawhtml}",
 1998          HTML       => "<APPLET $url> $options </APPLET>"
 1999       );
 2000 }
 2001 sub spf {
 2002   my($number,$format) = @_;  # attention, the order of format and number are reversed
 2003   $format = "%4.3g" unless $format;   # default value for format
 2004   sprintf($format, $number);
 2005   }
 2006 sub sspf {
 2007   my($number,$format) = @_;  # attention, the order of format and number are reversed
 2008   $format = "%4.3g" unless $format;   # default value for format
 2009   my $sign = $number>=0 ? " + " : " - ";
 2010   $number = $number>=0 ? $number : -$number;
 2011   $sign .sprintf($format, $number);
 2012   }
 2013 
 2014 =head2  Sorting and other list macros
 2015 
 2016 
 2017 
 2018   Usage:
 2019   lex_sort(@list);   # outputs list in lexigraphic (alphabetical) order
 2020   num_sort(@list);   # outputs list in numerical order
 2021   uniq( @list);      # outputs a list with no duplicates.  Order is unspecified.
 2022 
 2023   PGsort( \&sort_subroutine, @list);
 2024   # &sort_subroutine defines order. It's output must be 1 or 0 (true or false)
 2025 
 2026 =cut
 2027 
 2028 #  uniq gives unique elements of a list:
 2029  sub uniq {
 2030    my (@in) =@_;
 2031    my %temp = ();
 2032    while (@in) {
 2033           $temp{shift(@in)}++;
 2034       }
 2035    my @out =  keys %temp;  # sort is causing trouble with Safe.??
 2036    @out;
 2037 }
 2038 
 2039 sub lex_sort {
 2040   PGsort sub {$_[0] lt $_[1]}, @_;
 2041 }
 2042 sub num_sort {
 2043   PGsort sub {$_[0] < $_[1]}, @_;
 2044 }
 2045 
 2046 
 2047 =head2 Macros for handling tables
 2048 
 2049   Usage:
 2050   begintable( number_of_columns_in_table)
 2051   row(@dataelements)
 2052   endtable()
 2053 
 2054 Example of useage:
 2055 
 2056   BEGIN_TEXT
 2057     This problem tests calculating new functions from old ones:$BR
 2058     From the table below calculate the quantities asked for:$BR
 2059     \{begintable(scalar(@firstrow)+1)\}
 2060     \{row(" \(x\) ",@firstrow)\}
 2061     \{row(" \(f(x)\) ", @secondrow)\}
 2062     \{row(" \(g(x)\) ", @thirdrow)\}
 2063     \{row(" \(f'(x)\) ", @fourthrow)\}
 2064     \{row(" \(g'(x)\) ", @fifthrow)\}
 2065     \{endtable()\}
 2066 
 2067    (The arrays contain numbers which are placed in the table.)
 2068 
 2069   END_TEXT
 2070 
 2071 =cut
 2072 
 2073 sub begintable {
 2074   my ($number)=shift;   #number of columns in table
 2075   my %options = @_;
 2076   warn "begintable(cols) requires a number indicating the number of columns" unless defined($number);
 2077   my $out = "";
 2078   if ($displayMode eq 'TeX') {
 2079     $out .= "\n\\par\\smallskip\\begin{center}\\begin{tabular}{"  .  "|c" x $number .  "|} \\hline\n";
 2080     }
 2081   elsif ($displayMode eq 'Latex2HTML') {
 2082     $out .= "\n\\begin{rawhtml} <TABLE , BORDER=1>\n\\end{rawhtml}";
 2083     }
 2084   elsif ($displayMode eq 'HTML' || $displayMode eq 'HTML_tth' || $displayMode eq 'HTML_dpng' ||
 2085                $displayMode eq 'HTML_img' || $displayMode eq 'HTML_jsMath' ||
 2086          $displayMode eq 'HTML_asciimath' || $displayMode eq 'HTML_LaTeXMathML') {
 2087     $out .= "<TABLE BORDER=1>\n"
 2088   }
 2089   else {
 2090     $out = "Error: PGbasicmacros: begintable: Unknown displayMode: $displayMode.\n";
 2091     }
 2092   $out;
 2093   }
 2094 
 2095 sub endtable {
 2096   my $out = "";
 2097   if ($displayMode eq 'TeX') {
 2098     $out .= "\n\\end {tabular}\\end{center}\\par\\smallskip\n";
 2099     }
 2100   elsif ($displayMode eq 'Latex2HTML') {
 2101     $out .= "\n\\begin{rawhtml} </TABLE >\n\\end{rawhtml}";
 2102     }
 2103   elsif ($displayMode eq 'HTML' || $displayMode eq 'HTML_tth' || $displayMode eq 'HTML_dpng' ||
 2104                $displayMode eq 'HTML_img' || $displayMode eq 'HTML_jsMath' ||
 2105          $displayMode eq 'HTML_asciimath' || $displayMode eq 'HTML_LaTeXMathML') {
 2106     $out .= "</TABLE>\n";
 2107     }
 2108   else {
 2109     $out = "Error: PGbasicmacros: endtable: Unknown displayMode: $displayMode.\n";
 2110     }
 2111   $out;
 2112   }
 2113 
 2114 
 2115 sub row {
 2116   my @elements = @_;
 2117   my $out = "";
 2118   if ($displayMode eq 'TeX') {
 2119     while (@elements) {
 2120       $out .= shift(@elements) . " &";
 2121       }
 2122      chop($out); # remove last &
 2123      $out .= "\\\\ \\hline \n";
 2124      # carriage returns must be added manually for tex
 2125     }
 2126   elsif ($displayMode eq 'Latex2HTML') {
 2127     $out .= "\n\\begin{rawhtml}\n<TR>\n\\end{rawhtml}\n";
 2128     while (@elements) {
 2129       $out .= " \n\\begin{rawhtml}\n<TD> \n\\end{rawhtml}\n" . shift(@elements) . " \n\\begin{rawhtml}\n</TD> \n\\end{rawhtml}\n";
 2130       }
 2131     $out .= " \n\\begin{rawhtml}\n</TR> \n\\end{rawhtml}\n";
 2132   }
 2133   elsif ($displayMode eq 'HTML' || $displayMode eq 'HTML_tth' || $displayMode eq 'HTML_dpng'||
 2134          $displayMode eq 'HTML_img' || $displayMode eq 'HTML_jsMath' ||
 2135          $displayMode eq 'HTML_asciimath' || $displayMode eq 'HTML_LaTeXMathML') {
 2136     $out .= "<TR>\n";
 2137     while (@elements) {
 2138       $out .= "<TD>" . shift(@elements) . "</TD>";
 2139       }
 2140     $out .= "\n</TR>\n";
 2141   }
 2142   else {
 2143     $out = "Error: PGbasicmacros: row: Unknown displayMode: $displayMode.\n";
 2144     }
 2145   $out;
 2146 }
 2147 
 2148 =head2 Macros for displaying static images
 2149 
 2150   Usage:
 2151   $string = image($image, width => 100, height => 100, tex_size => 800)
 2152   $string = image($image, width => 100, height => 100, extra_html_tags => 'align="middle"', tex_size => 800)
 2153   $string = image([$image1, $image2], width => 100, height => 100, tex_size => 800)
 2154   $string = caption($string);
 2155   $string = imageRow([$image1, $image2 ], [$caption1, $caption2]);
 2156            # produces a complete table with rows of pictures.
 2157 
 2158 
 2159 =cut
 2160 
 2161 #   More advanced macros
 2162 sub image {
 2163   my $image_ref  = shift;
 2164   my @opt = @_;
 2165   unless (scalar(@opt) % 2 == 0 ) {
 2166     warn "ERROR in image macro.  A list of macros must be inclosed in square brackets.";
 2167   }
 2168   my %in_options = @opt;
 2169   my %known_options = (
 2170     width    => 100,
 2171     height   => 100,
 2172     tex_size => 800,
 2173     extra_html_tags => '',
 2174   );
 2175   # handle options
 2176   my %out_options = %known_options;
 2177   foreach my $opt_name (keys %in_options) {
 2178     if ( exists( $known_options{$opt_name} ) ) {
 2179       $out_options{$opt_name} = $in_options{$opt_name} if exists( $in_options{$opt_name} ) ;
 2180     } else {
 2181       die "Option $opt_name not defined for image. " .
 2182           "Default options are:<BR> ", display_options2(%known_options);
 2183     }
 2184   }
 2185   my $width       = $out_options{width};
 2186   my $height      = $out_options{height};
 2187   my $tex_size    = $out_options{tex_size};
 2188   my $width_ratio = $tex_size*(.001);
 2189   my @image_list  = ();
 2190 
 2191   if (ref($image_ref) =~ /ARRAY/ ) {
 2192     @image_list = @{$image_ref};
 2193   } else {
 2194     push(@image_list,$image_ref);
 2195   }
 2196 
 2197   my @output_list = ();
 2198     while(@image_list) {
 2199     my $imageURL = alias(shift @image_list);
 2200     my $out="";
 2201 
 2202     if ($displayMode eq 'TeX') {
 2203       my $imagePath = $imageURL; # in TeX mode, alias gives us a path, not a URL
 2204       if (defined $envir->{texDisposition} and $envir->{texDisposition} eq "pdf") {
 2205         # We're going to create PDF files with our TeX (using pdflatex), so
 2206         # alias should have given us the path to a PNG image. What we need
 2207         # to do is find out the dimmensions of this image, since pdflatex
 2208         # is too dumb to live.
 2209 
 2210         #my ($height, $width) = getImageDimmensions($imagePath);
 2211         ##warn "&image: $imagePath $height $width\n";
 2212         #unless ($height and $width) {
 2213         # warn "Couldn't get the dimmensions of image $imagePath.\n"
 2214         #}
 2215         #$out = "\\includegraphics[bb=0 0 $height $width,width=$width_ratio\\linewidth]{$imagePath}\n";
 2216         $out = "\\includegraphics[width=$width_ratio\\linewidth]{$imagePath}\n";
 2217       } else {
 2218         # Since we're not creating PDF files, alias should have given us the
 2219         # path to an EPS file. latex can get its dimmensions no problem!
 2220 
 2221         $out = "\\includegraphics[width=$width_ratio\\linewidth]{$imagePath}\n";
 2222       }
 2223     } elsif ($displayMode eq 'Latex2HTML') {
 2224       my $wid = ($envir->{onTheFlyImageSize} || 0)+ 30;
 2225       $out = qq!\\begin{rawhtml}\n<A HREF= "$imageURL" TARGET="_blank" onclick="window.open(this.href,this.target, 'width=$wid,height=$wid,scrollbars=yes,resizable=on'); return false;"><IMG SRC="$imageURL"  WIDTH="$width" HEIGHT="$height"></A>\n
 2226       \\end{rawhtml}\n !
 2227     } elsif ($displayMode eq 'HTML' || $displayMode eq 'HTML_tth' || $displayMode eq 'HTML_dpng' ||
 2228        $displayMode eq 'HTML_img' || $displayMode eq 'HTML_jsMath' ||
 2229        $displayMode eq 'HTML_asciimath' || $displayMode eq 'HTML_LaTeXMathML') {
 2230       my $wid = ($envir->{onTheFlyImageSize} || 0) +30;
 2231       $out = qq!<A HREF= "$imageURL" TARGET="_blank" onclick="window.open(this.href,this.target, 'width=$wid,height=$wid,scrollbars=yes,resizable=on'); return false;"><IMG SRC="$imageURL"  WIDTH="$width" HEIGHT="$height" $out_options{extra_html_tags} ></A>
 2232       !
 2233     } else {
 2234       $out = "Error: PGbasicmacros: image: Unknown displayMode: $displayMode.\n";
 2235     }
 2236     push(@output_list, $out);
 2237   }
 2238   return wantarray ? @output_list : $output_list[0];
 2239 }
 2240 
 2241 # This is legacy code.
 2242 sub images {
 2243   my @in = @_;
 2244   my @outlist = ();
 2245   while (@in) {
 2246      push(@outlist,&image( shift(@in) ) );
 2247    }
 2248   @outlist;
 2249 }
 2250 
 2251 
 2252 sub caption {
 2253   my ($out) = @_;
 2254   $out = " $out \n" if $displayMode eq 'TeX';
 2255   $out = " $out  " if $displayMode eq 'HTML';
 2256   $out = " $out  " if $displayMode eq 'HTML_tth';
 2257   $out = " $out  " if $displayMode eq 'HTML_dpng';
 2258   $out = " $out  " if $displayMode eq 'HTML_img';
 2259   $out = " $out  " if $displayMode eq 'HTML_jsMath';
 2260   $out = " $out  " if $displayMode eq 'HTML_asciimath';
 2261   $out = " $out  " if $displayMode eq 'HTML_LaTeXMathML';
 2262   $out = " $out  " if $displayMode eq 'Latex2HTML';
 2263     $out;
 2264 }
 2265 
 2266 sub captions {
 2267   my @in = @_;
 2268   my @outlist = ();
 2269   while (@in) {
 2270      push(@outlist,&caption( shift(@in) ) );
 2271   }
 2272   @outlist;
 2273 }
 2274 
 2275 sub imageRow {
 2276 
 2277   my $pImages = shift;
 2278   my $pCaptions=shift;
 2279   my $out = "";
 2280   my @images = @$pImages;
 2281   my @captions = @$pCaptions;
 2282   my $number = @images;
 2283   # standard options
 2284   my %options = ( 'tex_size' => 200,  # width for fitting 4 across
 2285                   'height' => 100,
 2286                   'width' => 100,
 2287                   @_            # overwrite any default options
 2288                 );
 2289 
 2290   if ($displayMode eq 'TeX') {
 2291     $out .= "\n\\par\\smallskip\\begin{center}\\begin{tabular}{"  .  "|c" x $number .  "|} \\hline\n";
 2292     while (@images) {
 2293       $out .= &image( shift(@images),%options ) . '&';
 2294     }
 2295     chop($out);
 2296     $out .= "\\\\ \\hline \n";
 2297     while (@captions) {
 2298       $out .= &caption( shift(@captions) ) . '&';
 2299     }
 2300     chop($out);
 2301     $out .= "\\\\ \\hline \n\\end {tabular}\\end{center}\\par\\smallskip\n";
 2302   } elsif ($displayMode eq 'Latex2HTML'){
 2303 
 2304     $out .= "\n\\begin{rawhtml} <TABLE  BORDER=1><TR>\n\\end{rawhtml}\n";
 2305     while (@images) {
 2306       $out .= "\n\\begin{rawhtml} <TD>\n\\end{rawhtml}\n" . &image( shift(@images),%options )
 2307               . "\n\\begin{rawhtml} </TD>\n\\end{rawhtml}\n" ;
 2308     }
 2309 
 2310     $out .= "\n\\begin{rawhtml}</TR><TR>\\end{rawhtml}\n";
 2311     while (@captions) {
 2312       $out .= "\n\\begin{rawhtml} <TH>\n\\end{rawhtml}\n".&caption( shift(@captions) )
 2313               . "\n\\begin{rawhtml} </TH>\n\\end{rawhtml}\n" ;
 2314     }
 2315 
 2316     $out .= "\n\\begin{rawhtml} </TR> </TABLE >\n\\end{rawhtml}";
 2317   } elsif ($displayMode eq 'HTML' || $displayMode eq 'HTML_tth' || $displayMode eq 'HTML_dpng' ||
 2318      $displayMode eq 'HTML_img' || $displayMode eq 'HTML_jsMath' ||
 2319      $displayMode eq 'HTML_asciimath' || $displayMode eq 'HTML_LaTeXMathML') {
 2320     $out .= "<P>\n <TABLE BORDER=2 CELLPADDING=3 CELLSPACING=2 ><TR ALIGN=CENTER    VALIGN=MIDDLE>\n";
 2321     while (@images) {
 2322       $out .= " \n<TD>". &image( shift(@images),%options ) ."</TD>";
 2323     }
 2324     $out .= "</TR>\n<TR>";
 2325     while (@captions) {
 2326       $out .= " <TH>". &caption( shift(@captions) ) ."</TH>";
 2327     }
 2328     $out .= "\n</TR></TABLE></P>\n"
 2329   }
 2330   else {
 2331     $out = "Error: PGbasicmacros: imageRow: Unknown languageMode: $displayMode.\n";
 2332     warn $out;
 2333   }
 2334   $out;
 2335 }
 2336 
 2337 
 2338 ###########
 2339 # Auxiliary macros
 2340 
 2341 sub display_options2{
 2342   my %options = @_;
 2343   my $out_string = "";
 2344   foreach my $key (keys %options) {
 2345     $out_string .= " $key => $options{$key},<BR>";
 2346   }
 2347   $out_string;
 2348 }
 2349 
 2350 
 2351 1;

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