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got rid of remaining calls to "wwerror". Fixes bug #530.
1 2 3 # Fun.pm 4 # methods: 5 # new Fun($rule,$graphRef) 6 # If $rule is a subroutine then a function object is created, 7 # with default data. If the graphRef is present the function is 8 # installed into the 9 # graph and the domain is reset to the graphRef's domain. 10 # If the $rule is another function object then a copy of that function is 11 # made with all of its data and it is installed in the graphRef if that is present. 12 # In this case the domain of the function is not affected by the domain of the graphRef. 13 # initial data 14 # @domain = ($tstart, $tstop) the domain of the function -- initially (-1,1) 15 # steps the number of steps in drawing -- initially 20 16 # color the pen color to draw with -- initially 'red' 17 # weight the width of the pen in pixels -- initially 2 18 # rule reference to a subroutine 19 # which calculates the function -- initially null 20 # graph reference to the enclosing graph -- initially $ref or else null 21 22 # What will the domain of new Fun($rule, $graphRef) be? 23 # It will be the same as $rule if $rule is actually another function object 24 # ELSE the same as the domain of $graphRef if that is present 25 # ELSE the interval (-1,1) 26 # public access methods: 27 # domain 28 # steps 29 # color 30 # rule 31 # weight 32 ; 33 34 =head1 NAME 35 36 Fun 37 38 =head1 SYNPOSIS 39 40 use Carp; 41 use GD; 42 use WWPlot; 43 use Fun; 44 $fn = new Fun( rule_reference); 45 $fn = new Fun( rule_reference , graph_reference); 46 $fn = new Fun ( x_rule_ref, y_rule_ref ); 47 $fn = new Fun ( x_rule_ref, y_rule_ref, graph_ref ); 48 49 =head1 DESCRIPTION 50 51 This module defines a parametric or non-parametric function object. The function object is designed to 52 be inserted into a graph object defined by WWPlot. 53 54 The following functions are provided: 55 56 57 58 =head2 new (non-parametric version) 59 60 =over 4 61 62 =item $fn = new Fun( rule_reference); 63 64 rule_reference is a reference to a subroutine which accepts a numerical value and returns a numerical value. 65 The Fun object will draw the graph associated with this subroutine. 66 For example: $rule = sub { my $x= shift; $x**2}; will produce a plot of the x squared. 67 The new method returns a reference to the function object. 68 69 =item $fn = new Fun( rule_reference , graph_reference); 70 71 The function is also placed into the printing queue of the graph object pointed to by graph_reference and the 72 domain of the function object is set to the domain of the graph. 73 74 =back 75 76 =head2 new (parametric version) 77 78 =over 4 79 80 =item $fn = new Fun ( x_rule_ref, y_rule_ref ); 81 82 A parametric function object is created where the subroutines refered to by x_rule_ref and y_rule_ref define 83 the x and y outputs in terms of the input t. 84 85 =item $fn = new Fun ( x_rule_ref, y_rule_ref, graph_ref ); 86 87 This variant inserts the parametric function object into the graph object referred to by graph_ref. The domain 88 of the function object is not adjusted. The domain's default value is (-1, 1). 89 90 =back 91 92 =head2 Properites 93 94 All of the properties are set using the construction $new_value = $fn->property($new_value) 95 and read using $current_value = $fn->property() 96 97 =over 4 98 99 =item tstart, tstop, steps 100 101 The domain of the function is (tstart, tstop). steps is the number of subintervals 102 used in graphing the function. 103 104 =item color 105 106 The color used to draw the function is specified by a word such as 'orange' or 'yellow'. 107 C<$fn->color('blue')> sets the drawing color to blue. The RGB values for the color are defined in the graph 108 object in which the function is drawn. If the color, e.g. 'mauve', is not defined by the graph object 109 then the function is drawn using the color 'default_color' which is always defined (and usually black). 110 111 =item x_rule 112 113 A reference to the subroutine used to calculate the x value of the graph. This is set to the identity function (x = t ) 114 when using the function object in non-parametric mode. 115 116 =item y_rule 117 118 A reference to the subroutine used to calculate the y value of the graph. 119 120 =item weight 121 122 The width in pixels of the pen used to draw the graph. The pen is square. 123 124 =back 125 126 =head2 Actions which affect more than one property. 127 128 =over 4 129 130 =item rule 131 132 This defines a non-parametric function. 133 134 $fn->rule(sub {my $x =shift; $x**2;} ) 135 136 is equivalent to 137 138 $fn->x_rule(sub {my $x = shift; $x;}); 139 $fn->y_rule(sub {my $x = shift; $x**2;); 140 141 $fn->rule() returns the reference to the y_rule. 142 143 =item domain 144 145 $array_ref = $fn->domain(-1,1) sets tstart to -1 and tstop to 1 and 146 returns a reference to an array containing this pair of numbers. 147 148 149 =item draw 150 151 $fn->draw($graph_ref) draws the function in the graph object pointed to by $graph_ref. If one of 152 the points bounding a subinterval is undefined then that segment is not drawn. This usually does the "right thing" for 153 functions which have simple singularities. 154 155 The graph object must 156 respond to the methods below. The draw call is mainly for internal use by the graph object. Most users will not 157 call it directly. 158 159 =over 4 160 161 =item $graph_ref->{colors} 162 163 a hash containing the defined colors 164 165 =item $graph_ref ->im 166 167 a GD image object 168 169 =item $graph_ref->lineTo(x,y, color_number) 170 171 draw line to the point (x,y) from the current position using the specified color. To obtain the color number 172 use a construction such as C<$color_number = $graph_ref->{colors}{'blue'};> 173 174 =item $graph_ref->lineTo(x,y,gdBrushed) 175 176 draw line to the point (x,y) using the pattern set by SetBrushed (see GD documentation) 177 178 =item $graph_ref->moveTo(x,y) 179 180 set the current position to (x,y) 181 182 =back 183 184 =back 185 186 =cut 187 188 BEGIN { 189 be_strict(); # an alias for use strict. This means that all global variable must contain main:: as a prefix. 190 } 191 192 package Fun; 193 194 195 #use "WWPlot.pm"; 196 #Because of the way problem modules are loaded 'use' is disabled. 197 198 199 200 201 202 @Fun::ISA = qw(WWPlot); 203 # import gdBrushed from GD. It unclear why, but a good many global methods haven't been imported. 204 sub gdBrushed { 205 &GD::gdBrushed(); 206 } 207 208 my $GRAPH_REFERENCE = "WWPlot"; 209 my $FUNCTION_REFERENCE = "Fun"; 210 211 my %fields =( 212 tstart => -1, # (tstart,$tstop) constitutes the domain 213 tstop => 1, 214 steps => 50, 215 color => 'blue', 216 x_rule => \&identity, 217 y_rule => \&identity, 218 weight => 2, # line thickness 219 ); 220 221 222 sub new { 223 my $class = shift; 224 # my ($rule,$graphRef) = @_; 225 226 my $self = { 227 _permitted => \%fields, 228 %fields, 229 }; 230 231 bless $self, $class; 232 $self -> _initialize(@_); 233 return $self; 234 } 235 236 sub identity { # the identity function 237 shift; 238 } 239 sub rule { # non-parametric functions are defined using rule; use x_rule and y_rule to define parametric functions 240 my $self = shift; 241 my $rule = shift; 242 my $out; 243 if ( defined($rule) ){ 244 $self->x_rule (\&identity); 245 $self->y_rule($rule); 246 $out = $self->y_rule; 247 } else { 248 $out = $self->y_rule 249 } 250 $out; 251 } 252 253 sub _initialize { 254 my $self = shift; 255 my ($xrule,$yrule, $rule,$graphRef); 256 my @input = @_; 257 if (ref($input[$#input]) eq $GRAPH_REFERENCE ) { 258 $graphRef = pop @input; # get the last argument if it refers to a graph. 259 $graphRef->fn($self); # Install this function in the graph. 260 } 261 262 if ( @input == 1 ) { # only one argument left -- this is a non parametric function 263 $rule = $input[0]; 264 if ( ref($rule) eq $FUNCTION_REFERENCE ) { # clone another function 265 my $k; 266 foreach $k (keys %fields) { 267 $self->{$k} = $rule->{$k}; 268 } 269 } else { 270 $self->rule($rule); 271 if (ref($graphRef) eq $GRAPH_REFERENCE) { # use graph to initialize domain 272 $self->domain($graphRef->xmin,$graphRef->xmax); 273 } 274 } 275 } elsif (@input == 2 ) { # two arguments -- parametric functions 276 $self->x_rule($input[0]); 277 $self->y_rule($input[1]); 278 279 } else { 280 die "Fun.pm:_initialize: Can't call function with more than two arguments"; 281 } 282 283 } 284 285 sub draw { 286 my $self = shift; # this function 287 my $g = shift; # the graph containing the function. 288 my $color; # get color scheme from graph 289 if ( defined( $g->{'colors'}{$self->color} ) ) { 290 $color = $g->{'colors'}{$self->color}; 291 } else { 292 $color = $g->{'colors'}{'default_color'}; # what you do if the color isn't there 293 } 294 my $brush = new GD::Image($self->weight,$self->weight); 295 my $brush_color = $brush->colorAllocate($g->im->rgb($color)); # transfer color 296 $g->im->setBrush($brush); 297 my $stepsize = ( $self->tstop - $self->tstart )/$self->steps; 298 299 my ($t,$x,$i,$y); 300 my $x_prev = undef; 301 my $y_prev = undef; 302 foreach $i (0..$self->steps) { 303 $t=$stepsize*$i + $self->tstart; 304 $x=&{$self->x_rule}( $t );; 305 $y=&{$self->y_rule}( $t ); 306 # Points where the function were not defined were not being handled 307 # gracefully. They would come as blank y values, which would ultimately 308 # trigger errors downstream unless y was undefined. 309 if(defined($y) and $y eq "") { $y = undef; } 310 if (defined($x) && defined($x_prev) && defined($y) && defined($y_prev) ) { 311 $g->lineTo($x, $y, gdBrushed); 312 } else { 313 $g->moveTo($x, $y) if defined($x) && defined($y); 314 } 315 $x_prev = $x; 316 $y_prev = $y; 317 } 318 } 319 320 sub domain { 321 my $self =shift; 322 my $tstart = shift; 323 my $tstop = shift; 324 if (defined($tstart) && defined($tstop) ) { 325 $self->tstart($tstart); 326 $self->tstop($tstop); 327 } 328 [$self->tstart,$self->tstop]; 329 } 330 331 332 sub DESTROY { 333 # doing nothing about destruction, hope that isn't dangerous 334 } 335 336 1;
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