ANS($ans->cmp(limits=>[0,1]));

We've implemented this on the problem but something it still throws the same error on some seeds (specifically seed value 1728). I've changed the limits interval to different values but to no avail. I was wondering if someone could tell us what we're doing wrong. I've attached a screenshot of the error and Ive included the problem file below (I've highlighted the limit declaration part).

Also, this happens on a MultiAnswer problem so perhaps that has something to do with it.

Thank you!

Patrick Spencer

Problem file source:

DOCUMENT();

loadMacros(

"MathObjects.pl",

"PeriodicRerandomization.pl",

"PGstandard.pl",

"contextLimitedPowers.pl",

"parserMultiAnswer.pl",

"unionTables.pl",

"AnswerFormatHelp.pl",

);

TEXT(beginproblem());

PeriodicRerandomization("3");

$showPartialCorrectAnswers = 1;

###########################################################################

# setup contexts and variables

###########################################################################

Context("Numeric");

LimitedPowers::OnlyPositiveIntegers();

@vars = ("x","y","z","r","s","t","m","n","p","q");

$ch1 = random(0,scalar(@vars)-1,1);

do {$ch2 = random(0,scalar(@vars)-1,1)} until ($ch2 != $ch1);

$v1 = $vars[$ch1];

$v2 = $vars[$ch2];

Context()->variables->are($v1=>"Real", $v2=>"Real");

$a = random(2,13);

$a2 = ($a)**2;

$p = 2*random(1,7);

$q = list_random(1,2,4,6,8,10);

$case = random(0,1,1);

if ($q == 1) {

$case = 0;

}

if ($case == 0) {

$f = ($q != 1) ? "\sqrt{\frac{$v1^{$p} $v2^{$q}}{$a2}}" : "\sqrt{\frac{$v1^{$p} $v2}{$a2}}";

$num = ($q != 1) ? Formula("$v1^{$p/2} $v2^{$q/2}")->reduce : Formula("$v1^{$p/2} sqrt($v2)")->reduce;

$den = Formula("$a");

} else {

$f = ($q != 1) ? "\sqrt{\frac{$v1^{$p}}{$a2 $v2^{$q}}}" : "\sqrt{\frac{$v1^{$p}}{$a2 $v2}}";

$num = Formula("$v1^{$p/2}")->reduce;

$den = ($q != 1) ? Formula("$a $v2^{$q/2}")->reduce : Formula("$a sqrt($v2)")->reduce;

}

$multians = MultiAnswer($num, $den)->with(

singleResult => 0,

allowBlankAnswers => 1,

checker => sub {

my ( $correct, $student, $self ) = @_;

my ( $c1, $c2 ) = @{$correct};

my ( $s1, $s2 ) = @{$student};

my ( $r1, $r2 ) = (0,0);

$s1 = Formula($s1) unless ($s1->type eq 'Formula' || $s1->type eq 'String');

$s2 = Formula($s2) unless ($s2->type eq 'Formula' || $s2->type eq 'String');

$s1 = Formula("0.1 $v1^{1000}") if ($s1->type eq 'String'); #bogus answer

$s2 = Formula("0.01$v2^{500}") if ($s2->type eq 'String'); #bogus answer

$r1 = 1 if ($c1 == $s1);

$r2 = 1 if ($c2 == $s2);

($r1,$r2) = (1,1) if ($c1 == -$s1 && $c2 == -$s2);

if ($c1*$s2 == $c2*$s1 && $c1 != $s1 && $c1 != -$s1) {

$self->setMessage(1,"Your answer can be simplified further");

$self->setMessage(2,"Your answer can be simplified further");

}

return [$r1,$r2];

}

);

if ($displayMode eq 'TeX') {

$displayfrac =

"\[ $f = ".$multians->ans_rule(10).$multians->ans_rule(10)." \]";

} else {

$displayfrac =

ColumnTable(

"\( \displaystyle $f = \)",

$multians->ans_rule(20).$BR.$HR.$multians->ans_rule(20),

indent => 0, separation => 10, valign => "MIDDLE"

);

}

$num->{limits} = [100,101];

$den->{limits} = [100,101];

###########################################################################

# state the problem

###########################################################################

Context()->texStrings;

BEGIN_TEXT

Simplify the radical expression. Assume that all variables represent positive quantities.

$PAR

$BCENTER

$displayfrac

$ECENTER

$BR

Write your answer using radical notation if necessary.

END_TEXT

###########################################################################

# check the answer

###########################################################################

ANS($multians->cmp());

###########################################################################

# use PeriodicRerandomization to write the answer and generate a new

# version of the problem

###########################################################################

if ($attempts_modp == 0 && $actualAttempts != 0) {

BEGIN_TEXT

$PAR

${BBOLD}Answer:${EBOLD} \(\displaystyle \frac{$num}{$den}\)

$PAR

END_TEXT

} else {

BEGIN_TEXT

$PAR

${BBOLD}Help:${EBOLD}

\{ AnswerFormatHelp("exponents", "Click here for help writing exponents and square roots.") \}

$BR

END_TEXT

}

Context()->normalStrings;

PeriodicStatus();

COMMENT('Features Periodic Rerandomization');

ENDDOCUMENT()