[LON-CAPA-cvs] cvs: modules /gerd/maxima caparesponse.pm default_homework.lcpm lonmaxima.pm

bisitz lon-capa-cvs@mail.lon-capa.org
Mon, 12 Jun 2006 13:51:17 -0000


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--bisitz1150120277
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bisitz		Mon Jun 12 09:51:17 2006 EDT

  Added files:                 
    /modules/gerd/maxima	caparesponse.pm default_homework.lcpm 

  Modified files:              
    /modules/gerd/maxima	lonmaxima.pm 
  Log:
  Work on mathresponse
  
  
--bisitz1150120277
Content-Type: text/plain
Content-Disposition: attachment; filename="bisitz-20060612095117.txt"

Index: modules/gerd/maxima/lonmaxima.pm
diff -u modules/gerd/maxima/lonmaxima.pm:1.2 modules/gerd/maxima/lonmaxima.pm:1.3
--- modules/gerd/maxima/lonmaxima.pm:1.2	Wed Mar 15 15:44:54 2006
+++ modules/gerd/maxima/lonmaxima.pm	Mon Jun 12 09:51:13 2006
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Interface routines to MAXIMA CAS
 #
-# $Id: lonmaxima.pm,v 1.2 2006/03/15 20:44:54 www Exp $
+# $Id: lonmaxima.pm,v 1.3 2006/06/12 13:51:13 bisitz Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -73,6 +73,17 @@
     if ($reply=~/^Error\:/) { return $reply; }
     return 'false';
 }
+
+sub maxima_check {
+    my ($response,$answer,$type,
+        $tol_type,$tol,
+        $sig_lbound,$sig_ubound,
+        $ans_fmt,$unit,$calc,$id_list,
+        $points,
+        $randomseed,
+        $reterror) = @_;
+    return 7;
+}
  
 1;
 __END__;

Index: modules/gerd/maxima/caparesponse.pm
+++ modules/gerd/maxima/caparesponse.pm
# The LearningOnline Network with CAPA
# caparesponse definition
#
# $Id: caparesponse.pm,v 1.1 2006/06/12 13:51:13 bisitz Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# LON-CAPA is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
#

package Apache::caparesponse;
use strict;
use capa;
use Safe::Hole;
use Apache::lonmaxima();
use Apache::lonlocal;
use Apache::lonnet;

BEGIN {
    &Apache::lonxml::register('Apache::caparesponse',('caparesponse','numericalresponse','stringresponse','formularesponse','mathresponse'));
}

my %answer;
my $cur_name;
sub start_answer {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    $cur_name = &Apache::lonxml::get_param('name',$parstack,$safeeval);
    if ($cur_name =~ /^\s*$/) { $cur_name = $Apache::lonxml::curdepth; }
    my $type = &Apache::lonxml::get_param('type',$parstack,$safeeval);
    if (!defined($type) && $tagstack->[-2] eq 'answergroup') {
	$type = &Apache::lonxml::get_param('type',$parstack,$safeeval,-2);
    }
    if (!defined($type)) { $type = 'ordered' };
    $answer{$cur_name}= { 'type' => $type,
			  'answers' => [] };
    return $result;
}

sub end_answer {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    undef($cur_name);
    return $result;
}

sub start_answergroup {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    my $id = $Apache::inputtags::response[-1];
    my $dis = &Apache::lonxml::get_param('answerdisplay',$parstack,$safeeval);
    if (defined($dis)) { $Apache::inputtags::answertxt{$id}=$dis; }
    return $result;
}

sub end_answergroup {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    return $result;
}

sub start_value {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
    my $result;
    if ( $target eq 'web' || $target eq 'tex' ||
	 $target eq 'grade' || $target eq 'webgrade' ||
	 $target eq 'answer' || $target eq 'analyze' ) {
	my $bodytext = &Apache::lonxml::get_all_text("/value",$parser,$style);
	$bodytext = &Apache::run::evaluate($bodytext,$safeeval,
					   $$parstack[-1]);
	push(@{ $answer{$cur_name}{'answers'} },$bodytext);
    }
    return $result;
}

sub end_value {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    return $result;
}

sub start_array {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
    my $result;
    if ( $target eq 'web' || $target eq 'tex' ||
	 $target eq 'grade' || $target eq 'webgrade' ||
	 $target eq 'answer' || $target eq 'analyze' ) {
	my $bodytext = &Apache::lonxml::get_all_text("/array",$parser,$style);
	my @values = &Apache::run::evaluate($bodytext,$safeeval,
					    $$parstack[-1]);
	push(@{ $answer{$cur_name}{'answers'} },@values);
    }
    return $result;
}

sub end_array {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    return $result;
}

sub start_unit {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    return $result;
}

sub end_unit {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    my $result;
    return $result;
}

sub start_numericalresponse {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
    &Apache::lonxml::register('Apache::caparesponse',('answer','answergroup','value','array','unit'));
    my $id = &Apache::response::start_response($parstack,$safeeval);
    my $result;
    undef(%answer);
    undef(%{$safeeval->varglob('LONCAPA::CAPAresponse_args')});
    if ($target eq 'edit') {
	$result.=&Apache::edit::tag_start($target,$token);
	$result.=&Apache::edit::text_arg('Answer:','answer',$token);
	if ($token->[1] eq 'numericalresponse') {
	    $result.=&Apache::edit::text_arg('Incorrect Answers:','incorrect',
					     $token).
		&Apache::loncommon::help_open_topic('numerical_wrong_answers');
	    $result.=&Apache::edit::text_arg('Unit:','unit',$token,5).
		&Apache::loncommon::help_open_topic('Physical_Units');
	    $result.=&Apache::edit::text_arg('Format:','format',$token,4).
		&Apache::loncommon::help_open_topic('Numerical_Response_Format');
	} elsif ($token->[1] eq 'formularesponse') {
	    $result.=&Apache::edit::text_arg('Sample Points:','samples',
					     $token,40).
	      &Apache::loncommon::help_open_topic('Formula_Response_Sampling');
	}
	$result.=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
    } elsif ($target eq 'modified') {
	my $constructtag;
	if ($token->[1] eq 'numericalresponse') {
	    $constructtag=&Apache::edit::get_new_args($token,$parstack,
						      $safeeval,'answer',
 						      'incorrect','unit',
						      'format');
	} elsif ($token->[1] eq 'formularesponse') {
	    $constructtag=&Apache::edit::get_new_args($token,$parstack,
						      $safeeval,'answer',
						      'samples');
	}
	if ($constructtag) {
	    $result = &Apache::edit::rebuild_tag($token);
	    $result.=&Apache::edit::handle_insert();
	}
    } elsif ($target eq 'meta') {
	$result=&Apache::response::meta_package_write('numericalresponse');
    } elsif ($target eq 'answer' || $target eq 'grade') {
	&Apache::response::reset_params();
    } elsif ($target eq 'web') {
	my $partid = $Apache::inputtags::part;
	my $hideunit=&Apache::lonnet::EXT('resource.'.$partid.'_'.$id.'.turnoffunit');
	&Apache::lonxml::debug("Got unit $hideunit for $partid $id");
	#no way to enter units, with radio buttons
	if (lc($hideunit) eq "yes") {
	    my $unit=&Apache::lonxml::get_param_var('unit',$parstack,
						    $safeeval);
	    if ($unit =~ /\S/) { $result.=" (in $unit) "; }
	}
	if (  &Apache::response::show_answer() ) {
	    my $answertxt;
	    my (@answers)=&Apache::lonxml::get_param_var('answer',$parstack,
							 $safeeval);
	    my (@formats)=&Apache::lonxml::get_param_var('format',$parstack,
							 $safeeval);
	    my $unit=&Apache::lonxml::get_param_var('unit',$parstack,
						    $safeeval);
	    for (my $i=0; $i <= $#answers; $i++) {
		my $answer=$answers[$i];
		if ( scalar(@$tagstack)
		     && $tagstack->[-1] ne 'numericalresponse') {
		    $answertxt.=$answer.',';
		} else {
		    my $format;
		    if ($#formats > 0) {
			$format=$formats[$i];
		    } else {
			$format=$formats[0];
		    }
		    if ($unit=~/\$/) { $format="\$".$format; $unit=~s/\$//g; }
		    if ($unit=~/\,/) { $format="\,".$format; $unit=~s/\,//g; }
		    my $formatted=&format_number($answer,$format,$target,
						 $safeeval);
		    $answertxt.=$formatted.',';
		}
	    }
	    chop $answertxt;
	    if ($target eq 'web') {
		$answertxt.=" $unit ";
	    }
	    $Apache::inputtags::answertxt{$id}=$answertxt;
	}
    }
    return $result;
}

sub check_submission {
    my ($response,$partid,$id,$tag,$parstack,$safeeval,$ignore_sig)=@_;
    my $args_ref= \%{$safeeval->varglob('LONCAPA::CAPAresponse_args')};
    $$args_ref{'response'}=$response;
    my $hideunit=&Apache::lonnet::EXT('resource.'.$partid.'_'.$id.'.turnoffunit');
    
    foreach my $arg ('type','tol','sig','format','unit','calc',
		     'samples') {
	$$args_ref{$arg}=
	    &Apache::lonxml::get_param($arg,$parstack,$safeeval);
    }
    foreach my $key (keys(%Apache::inputtags::params)) {
	$$args_ref{$key}=$Apache::inputtags::params{$key};
    }
    
    #no way to enter units, with radio buttons
    if ($Apache::lonhomework::type eq 'exam' ||
	lc($hideunit) eq "yes") {
	delete($$args_ref{'unit'});
    }
    #sig fig don't make much sense either
    if (($Apache::lonhomework::type eq 'exam' ||
	 &Apache::response::submitted('scantron') ||
	 $ignore_sig) &&
	$tag eq 'numericalresponse') {
	delete($$args_ref{'sig'});
    }
    
    if ($tag eq 'formularesponse') {
	$$args_ref{'type'}='fml';
    } elsif ($tag eq 'mathresponse') {
        $$args_ref{'type'}='mth';
    } elsif ($tag eq 'numericalresponse') {
	$$args_ref{'type'}='float';
    }
    my @answer=&Apache::lonxml::get_param_var('answer',$parstack,$safeeval);
    &Apache::lonxml::debug('answer is'.join(':',@answer));
    if (@answer && defined($answer[0])) {
	$answer{'INTERNAL'}= {'type' => 'ordered',
			      'answers' => \@answer };
    }
    #FIXME would be nice if we could save name so we know who graded him
    #correct
    my (%results,@final_awards,@final_msgs,@names);
    foreach my $name (keys(%answer)) {
	&Apache::lonxml::debug(" doing $name with ".join(':',@{ $answer{$name}{'answers'} }));
	@{$safeeval->varglob('LONCAPA::CAPAresponse_answer')}=@{ $answer{$name}{'answers'} };
	my ($result,@msgs) = 
	    &Apache::run::run("&caparesponse_check_list()",$safeeval);
	&Apache::lonxml::debug('msgs are '.join(':',@msgs));
	my ($awards)=split(/:/,$result);
	my @awards= split(/,/,$awards);
	my ($ad, $msg) = &Apache::inputtags::finalizeawards(\@awards,\@msgs);
	$results{$name}= [$ad,$msg];
	push(@final_awards,$ad);
	push(@final_msgs,$msg);
	push(@names,$name);
    }
    my ($ad, $msg, $name) = &Apache::inputtags::finalizeawards(\@final_awards,
							       \@final_msgs,
							       \@names,1);
    return($ad,$msg);
}

sub end_numericalresponse {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
    my $increment=1;
    my $result = '';
    if (!$Apache::lonxml::default_homework_loaded) {
	&Apache::lonxml::default_homework_load($safeeval);
    }
    my $partid = $Apache::inputtags::part;
    my $id = $Apache::inputtags::response[-1];
    my $tag;
    my $safehole = new Safe::Hole;
    $safeeval->share_from('capa',['&caparesponse_capa_check_answer']);
    $safehole->wrap(\&Apache::lonmaxima::maxima_check,$safeeval,'&maxima_check');

    if (scalar(@$tagstack)) { $tag=$$tagstack[-1]; }
    if ( $target eq 'grade' && &Apache::response::submitted() ) {
	&Apache::response::setup_params($tag,$safeeval);
	if ($Apache::lonhomework::type eq 'exam' && 
	    (($tag eq 'formularesponse') || ($tag eq 'mathresponse'))) {
	    $increment=&Apache::response::scored_response($partid,$id);
	} else {
	    my $response = &Apache::response::getresponse();
	    if ( $response =~ /[^\s]/) {
		my %previous = &Apache::response::check_for_previous($response,$partid,$id);
		&Apache::lonxml::debug("submitted a $response<br>\n");
		&Apache::lonxml::debug($$parstack[-1] . "\n<br>");
		
		if ( &Apache::response::submitted('scantron')) {
		    my ($values,$display)=&make_numerical_bubbles($partid,$id,
						  $target,$parstack,$safeeval);
		    $response=$values->[$response];
		}
		$Apache::lonhomework::results{"resource.$partid.$id.submission"}=$response;
		my ($ad,$msg)=&check_submission($response,$partid,$id,
						$tag,$parstack,$safeeval);

		&Apache::lonxml::debug('ad is'.$ad);
		if ($ad eq 'SIG_FAIL') {
		    my ($sig_u,$sig_l)=
			&get_sigrange($Apache::inputtags::params{'sig'});
		    $msg=join(':',$msg,$sig_l,$sig_u);
		    &Apache::lonxml::debug("sigs bad $sig_u $sig_l ".
					   $Apache::inputtags::params{'sig'});
		}
		&Apache::lonxml::debug("\n<br>result:$result:$Apache::lonxml::curdepth<br>\n");
		if ($Apache::lonhomework::type eq 'survey' &&
		    ($ad eq 'INCORRECT' || $ad eq 'APPROX_ANS' ||
		     $ad eq 'EXACT_ANS')) {
		    $ad='SUBMITTED';
		}
		&Apache::response::handle_previous(\%previous,$ad);
		$Apache::lonhomework::results{"resource.$partid.$id.awarddetail"}=$ad;
		$Apache::lonhomework::results{"resource.$partid.$id.awardmsg"}=$msg;
		$result='';
	    }
	}
    } elsif ($target eq 'web' || $target eq 'tex') {
	my (@answers)=&Apache::lonxml::get_param_var('answer',$parstack,
						     $safeeval);
	my $award = $Apache::lonhomework::history{"resource.$Apache::inputtags::part.solved"};
	my $status = $Apache::inputtags::status['-1'];
	if ($Apache::lonhomework::type eq 'exam') {
	    my ($bubble_values,$bubble_display)=
		&make_numerical_bubbles($partid,$id,$target,$parstack,
					$safeeval);
	    my $number_of_bubbles = scalar(@{ $bubble_values });
	    my $unit=&Apache::lonxml::get_param_var('unit',$parstack,
						    $safeeval);
	    my @alphabet=('A'..'Z');
	    if ($target eq 'web') {
		if ($tag eq 'numericalresponse') {
		    if ($unit=~/\S/) {$result.=' (in '.$unit.')<br /><br />';}
		    $result.= '<table border="1"><tr>';
		    my $previous=$Apache::lonhomework::history{"resource.$Apache::inputtags::part.$id.submission"};
		    for (my $ind=0;$ind<$number_of_bubbles;$ind++) {
			my $checked='';
			if ($previous eq $bubble_values->[$ind]) {
			    $checked=" checked='on' ";
			}
			$result.='<td><input type="radio" name="HWVAL_'.$id.
			    '" value="'.$bubble_values->[$ind].'" '.$checked
			    .' /><b>'.$alphabet[$ind].'</b>: '.
			    $bubble_display->[$ind].'</td>';
		    }
		    $result.='</tr></table>';
		}
	    } elsif ($target eq 'tex') {
		if ((defined $unit) and ($unit=~/\S/) and ($Apache::lonhomework::type eq 'exam')) {
		    $result.=' \textit{(in} \verb|'.$unit.'|\textit{)} ';
		}
		if ($tag eq 'numericalresponse') {
		    my ($celllength,$number_of_tables,@table_range)=
			&get_table_sizes($number_of_bubbles,$bubble_display);
		    my $j=0;
		    my $cou=0;
		    $result.='\vskip -1 mm \noindent \begin{enumerate}\item[\textbf{'.$Apache::lonxml::counter.'}.]';
		    for (my $i=0;$i<$number_of_tables;$i++) {
			$result.='\vskip -1 mm \noindent \setlength{\tabcolsep}{2 mm}\begin{tabular}{';
			for (my $ind=0;$ind<$table_range[$j];$ind++) {
			    $result.='p{3 mm}p{'.$celllength.' mm}';
			}
			$result.='}';
			for (my $ind=$cou;$ind<$cou+$table_range[$j];$ind++) {
			    $result.='\hskip -4 mm {\small \textbf{'.$alphabet[$ind].'}}$\bigcirc$ & \hskip -3 mm {\small '.$bubble_display->[$ind].'} ';
			    if ($ind != $cou+$table_range[$j]-1) {$result.=' & ';}
			}
			$cou += $table_range[$j];
			$j++;
			$result.='\\\\\end{tabular}\vskip 0 mm ';
		    }
		    $result.='\end{enumerate}';
		} else {
		    $increment = &Apache::response::repetition();
		}
	    }
	}
    } elsif ($target eq 'edit') {
	$result.='</td></tr>'.&Apache::edit::end_table;
    } elsif ($target eq 'answer' || $target eq 'analyze') {
	my $part_id="$partid.$id";
	if ($target eq 'analyze') {
	    push (@{ $Apache::lonhomework::analyze{"parts"} },$part_id);
	    $Apache::lonhomework::analyze{"$part_id.type"} = $tag;
	    my (@incorrect)=&Apache::lonxml::get_param_var('incorrect',$parstack,$safeeval);
	    if ($#incorrect eq 0) { @incorrect=(split(/,/,$incorrect[0])); }
	    push (@{ $Apache::lonhomework::analyze{"$part_id.incorrect"} }, @incorrect);
	    &Apache::response::check_if_computed($token,$parstack,
						 $safeeval,'answer');
	}
	if (scalar(@$tagstack)) {
	    &Apache::response::setup_params($tag,$safeeval);
	}
	my (@answers)=&Apache::lonxml::get_param_var('answer',$parstack,$safeeval);
	my (@formats)=&Apache::lonxml::get_param_var('format',$parstack,$safeeval);
	my $unit=&Apache::lonxml::get_param_var('unit',$parstack,$safeeval);
	my $type=&Apache::lonxml::get_param('type',$parstack,$safeeval);
	
	if ($target eq 'answer') {
	    $result.=&Apache::response::answer_header($tag);
	    if ($tag eq 'numericalresponse'
		&& $Apache::lonhomework::type eq 'exam') {
		my ($bubble_values,undef,$correct) = &make_numerical_bubbles($partid,
					     $id,$target,$parstack,$safeeval);
		$result.=&Apache::response::answer_part($tag,$correct);
	    }
	}
	my ($sigline,$tolline);
	for(my $i=0;$i<=$#answers;$i++) {
	    my $ans=$answers[$i];
	    my $fmt=$formats[0];
	    if (@formats && $#formats) {$fmt=$formats[$i];}
	    my ($high,$low);
	    if ($Apache::inputtags::params{'tol'}) {
		($high,$low)=&get_tolrange($ans,$Apache::inputtags::params{'tol'});
	    }
	    my ($sighigh,$siglow);
	    if ($Apache::inputtags::params{'sig'}) {
		($sighigh,$siglow)=&get_sigrange($Apache::inputtags::params{'sig'});
	    }
	    if ($fmt && $tag eq 'numericalresponse') {
		$fmt=~s/e/E/g;
		if ($unit=~/\$/) { $fmt="\$".$fmt; $unit=~s/\$//g; }
		if ($unit=~/\,/) { $fmt="\,".$fmt; $unit=~s/\,//g; }
		$ans = &format_number($ans,$fmt,$target,$safeeval);
		#if ($high) {
		#    $high=&format_number($high,$fmt,$target,$safeeval);
		#    $low =&format_number($low,$fmt,$target,$safeeval);
		#}
	    }
	    if ($target eq 'answer') {
		if ($high && $tag eq 'numericalresponse') {
		    $ans.=' ['.$low.','.$high.']';
		    $tolline .= "[$low, $high]";
		}
		if (defined($sighigh) && $tag eq 'numericalresponse') {
		    if ($env{'form.answer_output_mode'} eq 'tex') {
			$ans.= " Sig $siglow - $sighigh";
		    } else {
			$ans.= " Sig <i>$siglow - $sighigh</i>";
			$sigline .= "[$siglow, $sighigh]";
		    }
		}
		$result.=&Apache::response::answer_part($tag,$ans);
	    } elsif ($target eq 'analyze') {
		push (@{ $Apache::lonhomework::analyze{"$part_id.answer"} }, $ans);
		if ($high) {
		    push (@{ $Apache::lonhomework::analyze{"$part_id.ans_high"} }, $high);
		    push (@{ $Apache::lonhomework::analyze{"$part_id.ans_low"} }, $low);
		}
		if ($fmt) {
		    push (@{ $Apache::lonhomework::analyze{"$part_id.format"} }, $fmt);
		}
	    }
	}

	my @fmt_ans;
	for(my $i=0;$i<=$#answers;$i++) {
	    my $ans=$answers[$i];
	    my $fmt=$formats[0];
	    if (@formats && $#formats) {$fmt=$formats[$i];}
	    if ($fmt && $tag eq 'numericalresponse') {
		$fmt=~s/e/E/g;
		if ($unit=~/\$/) { $fmt="\$".$fmt; $unit=~s/\$//g; }
		if ($unit=~/\,/) { $fmt="\,".$fmt; $unit=~s/\,//g; }
		$ans = &format_number($ans,$fmt,$target,$safeeval);
		if ($fmt=~/\$/ && $unit!~/\$/) { $ans=~s/\$//; }
	    }
	    push(@fmt_ans,$ans);
	}
	my $response=join(', ',@fmt_ans);
	my $hideunit=&Apache::lonnet::EXT('resource.'.$partid.'_'.
					  $id.'.turnoffunit');
	if ($unit ne ''  && 
	    ! ($Apache::lonhomework::type eq 'exam' ||
	       lc($hideunit) eq "yes") )  {
	    my $cleanunit=$unit;
	    $cleanunit=~s/\$\,//g;
	    $response.=" $cleanunit";
	}

	my ($ad,$msg)=&check_submission($response,$partid,$id,$tag,
					$parstack,$safeeval);
	if ($ad ne 'EXACT_ANS' && $ad ne 'APPROX_ANS') {
	    my $error;
	    if ($tag eq 'formularesponse') {
		$error=&mt('Computer\'s answer is incorrect ("[_1]").',$response);
	    } else {
		# answer failed check if it is sig figs that is failing
		my ($ad,$msg)=&check_submission($response,$partid,$id,
						$tag,$parstack,
						$safeeval,1);
		if ($sigline ne '') {
		    $error=&mt('Computer\'s answer is incorrect ("[_1]"). It is likely that the tolerance range [_2] or significant figures [_3] need to be adjusted.',$response,$tolline,$sigline);
		} else {
		    $error=&mt('Computer\'s answer is incorrect ("[_1]"). It is likely that the tolerance range [_2] needs to be adjusted.',$response,$tolline);
		}
	    }
	    if ($ad ne 'EXACT_ANS' && $ad ne 'APPROX_ANS') {
		&Apache::lonxml::error($error);
	    } else {
		&Apache::lonxml::warning($error);
	    }
	}

	if (defined($unit) and ($unit ne '') and
	    $tag eq 'numericalresponse') {
	    if ($target eq 'answer') {
		if ($env{'form.answer_output_mode'} eq 'tex') {
		    $result.=&Apache::response::answer_part($tag,
							    " Unit: $unit ");
		} else {
		    $result.=&Apache::response::answer_part($tag,
							    "Unit: <b>$unit</b>");
		}
	    } elsif ($target eq 'analyze') {
		push (@{ $Apache::lonhomework::analyze{"$part_id.unit"} }, $unit);
	    }
	}
	if ($tag eq 'formularesponse' && $target eq 'answer') {
	    my $samples=&Apache::lonxml::get_param('samples',$parstack,$safeeval);
	    $result.=&Apache::response::answer_part($tag,$samples);
	}
	if ($target eq 'answer') {
	    $result.=&Apache::response::answer_footer($tag);
	}
    }
    if ($target eq 'grade' || $target eq 'web' || $target eq 'answer' || 
	$target eq 'tex' || $target eq 'analyze') {
	&Apache::lonxml::increment_counter($increment);
    }
    &Apache::response::end_response;
    return $result;
}

sub get_table_sizes {
    my ($number_of_bubbles,$rbubble_values)=@_;
    my $scale=2; #mm for one digit
    my $cell_width=0;
    foreach my $member (@$rbubble_values) {
	my $cell_width_real=0;
	if ($member=~/(\+|-)?(\d*)\.?(\d*)\s*\$?\\times\s*10\^{(\+|-)?(\d+)}\$?/) {
	    $cell_width_real=(length($2)+length($3)+length($5)+7)*$scale;
	} elsif ($member=~/(\d*)\.?(\d*)(E|e)(\+|-)?(\d*)/) {
	    $cell_width_real=(length($1)+length($2)+length($5)+9)*$scale;
        } elsif ($member=~/(\d*)\.(\d*)/) {
	    $cell_width_real=(length($1)+length($2)+3)*$scale;
	} else {
	    $cell_width_real=(length($member)+1)*$scale*0.9;
	}
	if ($cell_width_real>$cell_width) {$cell_width=$cell_width_real;}
    }
    $cell_width+=8; 
    my $textwidth;
    if ($env{'form.textwidth'} ne '') {
	$env{'form.textwidth'}=~/(\d*)\.?(\d*)/;
	$textwidth=$1.'.'.$2;
    } else {
	$env{'form.textwidth'}=~/(\d+)\.?(\d*)/;
	$textwidth=$1.'.'.$2;
    }
    my $bubbles_per_line=int($textwidth/$cell_width);
    if ($bubbles_per_line > $number_of_bubbles) {
	$bubbles_per_line=$number_of_bubbles;
    }elsif (($bubbles_per_line > $number_of_bubbles/2) && ($number_of_bubbles % 2==0)) {$bubbles_per_line=$number_of_bubbles/2;}
    my $number_of_tables = int($number_of_bubbles/$bubbles_per_line);
    my @table_range = ();
    for (my $i=0;$i<$number_of_tables;$i++) {push @table_range,$bubbles_per_line;}
    if ($number_of_bubbles % $bubbles_per_line) {
	$number_of_tables++;
	push @table_range,($number_of_bubbles % $bubbles_per_line);
    }
    $cell_width-=8;
    $cell_width=$cell_width*3/4;
    return ($cell_width,$number_of_tables,@table_range);
}

sub format_number {
    my ($number,$format,$target,$safeeval)=@_;
    my $ans;
    if ($format eq '') {
	#What is the number? (integer,decimal,floating point)
	if ($number=~/^(\d*\.?\d*)(E|e)[+\-]?(\d*)$/) {
	    $format = '3e';
	} elsif ($number=~/^(\d*)\.(\d*)$/) {
	    $format = '4f';
	} elsif ($number=~/^(\d*)$/) {
	    $format = 'd';
	}
    }
    if (!$Apache::lonxml::default_homework_loaded) {
	&Apache::lonxml::default_homework_load($safeeval);
    }
    $ans=&Apache::run::run("&prettyprint(q\0$number\0,q\0$format\0,q\0$target\0)",$safeeval);
    return $ans;
}

sub make_numerical_bubbles {
    my ($part,$id,$target,$parstack,$safeeval) =@_;
    
    my $number_of_bubbles = 
	&Apache::response::get_response_param($part.'_'.$id,'numbubbles',8);

    my ($format)=&Apache::lonxml::get_param_var('format',$parstack,$safeeval);
    my ($answer)=&Apache::lonxml::get_param_var('answer',$parstack,$safeeval);
    my (@incorrect)=&Apache::lonxml::get_param_var('incorrect',$parstack,
						   $safeeval);
    if ($#incorrect eq 0) { @incorrect=(split(/,/,$incorrect[0])); }
    
    my @bubble_values=();
    my @alphabet=('A'..'Z');

    &Apache::lonxml::debug("answer is $answer incorrect is @incorrect");
    my @oldseed=&Math::Random::random_get_seed();
    if (@incorrect) {
	&Apache::lonxml::debug("inside ".(scalar(@incorrect)+1 gt $number_of_bubbles));
	if (defined($incorrect[0]) &&
	    scalar(@incorrect)+1 >= $number_of_bubbles) {
	    &Apache::lonxml::debug("inside ".(scalar(@incorrect)+1).":$number_of_bubbles");
	    &Apache::response::setrandomnumber();
	    my @rand_inc=&Math::Random::random_permutation(@incorrect);
	    @bubble_values=@rand_inc[0..($number_of_bubbles-2)];
	    @bubble_values=sort {$a <=> $b} (@bubble_values,$answer);
	    &Apache::lonxml::debug("Answer was :$answer: returning :".$#bubble_values.": which are :".join(':',@bubble_values));
	    &Math::Random::random_set_seed(@oldseed);

	    my $correct;
	    for(my $i=0; $i<=$#bubble_values;$i++) {
		if ($bubble_values[$i] eq $answer) {
		    $correct = $alphabet[$i];
		    last;
		}
	    }

	    if (defined($format) && $format ne '') {
		my @bubble_display;
		foreach my $value (@bubble_values) {
		    push(@bubble_display,
			 &format_number($value,$format,$target,$safeeval));
		}
		return (\@bubble_values,\@bubble_display,$correct);
	    } else {
		return (\@bubble_values,\@bubble_values,$correct);
	    }
	}
	if (defined($incorrect[0]) &&
	    scalar(@incorrect)+1 < $number_of_bubbles) {
	    &Apache::lonxml::warning("Not enough incorrect answers were specified in the incorrect array, ignoring the specified incorrect answers and instead generating them (".join(',',@incorrect).").");
	}
    }
    my @factors = (1.13,1.17,1.25,1.33,1.45); #default values of factors
    my @powers = (1..$number_of_bubbles);
    &Apache::response::setrandomnumber();
    my $ind=&Math::Random::random_uniform_integer(1,0,$#powers);
    my $power = $powers[$ind];
    $ind=&Math::Random::random_uniform_integer(1,0,$#factors);
    my $factor = $factors[$ind];
    my @bubble_display;
    for ($ind=0;$ind<$number_of_bubbles;$ind++) {
	$bubble_values[$ind] = $answer*($factor**($power-$powers[$#powers-$ind]));
	$bubble_display[$ind] = &format_number($bubble_values[$ind],
					       $format,$target,$safeeval);

    }
    my $correct = $alphabet[$number_of_bubbles-$power];
    &Math::Random::random_set_seed(@oldseed);
    return (\@bubble_values,\@bubble_display,$correct);
}

sub get_tolrange {
    my ($ans,$tol)=@_;
    my ($high,$low);
    if ($tol =~ /%$/) {
	chop($tol);
	my $change=$ans*($tol/100.0);
	$high=$ans+$change;
	$low=$ans-$change;
    } else {
	$high=$ans+$tol;
	$low=$ans-$tol;
    }
    return ($high,$low);
}

sub get_sigrange {
    my ($sig)=@_;
    &Apache::lonxml::debug("Got a sig of :$sig:");
    my $courseid=$env{'request.course.id'};
    if (lc($env{"course.$courseid.disablesigfigs"}) eq 'yes') {
	return (15,0);
    }
    my $sig_lbound;
    my $sig_ubound;
    if ($sig eq '') {
	$sig_lbound = 0; #SIG_LB_DEFAULT
	$sig_ubound =15; #SIG_UB_DEFAULT
    } else {
	($sig_lbound,$sig_ubound) = split(/,/,$sig);
	if (!defined($sig_lbound)) {
	    $sig_lbound = 0; #SIG_LB_DEFAULT
	    $sig_ubound =15; #SIG_UB_DEFAULT
	}
	if (!defined($sig_ubound)) { $sig_ubound=$sig_lbound; }
    }
    if (($sig_ubound<$sig_lbound) ||
	($sig_lbound > 15) ||
	($sig =~/(\+|-)/ ) ) {
	my $errormsg=&mt("Invalid Significant figures detected")." ($sig)";
	if ($env{'request.state'} eq 'construct') {
	    $errormsg.=
		&Apache::loncommon::help_open_topic('Significant_Figures');
	}
	&Apache::lonxml::error($errormsg);
    }
    return ($sig_ubound,$sig_lbound);
}

sub start_stringresponse {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
    my $result;
    my $id = &Apache::response::start_response($parstack,$safeeval);
    if ($target eq 'meta') {
	$result=&Apache::response::meta_package_write('stringresponse');
    } elsif ($target eq 'edit') {
	$result.=&Apache::edit::tag_start($target,$token);
	$result.=&Apache::edit::text_arg('Answer:','answer',$token);
	$result.=&Apache::edit::select_arg('Type:','type',
			 [['cs','Case Sensitive'],['ci','Case Insensitive'],
			  ['mc','Case Insensitive, Any Order'],
			  ['re','Regular Expression']],$token);
	$result.=&Apache::edit::text_arg('String to display for answer:',
					 'answerdisplay',$token);
	$result.=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
    } elsif ($target eq 'modified') {
	my $constructtag;
	$constructtag=&Apache::edit::get_new_args($token,$parstack,
						  $safeeval,'answer',
						  'type','answerdisplay');
	if ($constructtag) {
	    $result = &Apache::edit::rebuild_tag($token);
	    $result.=&Apache::edit::handle_insert();
	}
    } elsif ($target eq 'web') {
	if (  &Apache::response::show_answer() ) {
	    my $answer=
	       &Apache::lonxml::get_param('answerdisplay',$parstack,$safeeval);
	    if (!defined $answer || $answer eq '') {
		$answer=
		    &Apache::lonxml::get_param('answer',$parstack,$safeeval);
	    }
	    $Apache::inputtags::answertxt{$id}=$answer;
	} 
    } elsif ($target eq 'answer' || $target eq 'grade') {
	&Apache::response::reset_params();
    }
    return $result;
}

sub end_stringresponse {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;

    my $result = '';
    my $part=$Apache::inputtags::part;
    my $id=$Apache::inputtags::response[-1];
    my $answer=&Apache::lonxml::get_param('answer',$parstack,$safeeval);
    my $type=&Apache::lonxml::get_param('type',$parstack,$safeeval);
    my $answerdisplay=&Apache::lonxml::get_param('answerdisplay',$parstack,$safeeval);
    &Apache::lonxml::debug("current $answer ".$token->[2]);
    if (!$Apache::lonxml::default_homework_loaded) {
	&Apache::lonxml::default_homework_load($safeeval);
    }
    if ( $target eq 'grade' && &Apache::response::submitted() ) {
	&Apache::response::setup_params('stringresponse',$safeeval);
	$safeeval->share_from('capa',['&caparesponse_capa_check_answer']);
	if ($Apache::lonhomework::type eq 'exam' ||
	    &Apache::response::submitted('scantron')) {
	    &Apache::response::scored_response($part,$id);

	} else {
	    my $response = &Apache::response::getresponse();
	    if ( $response =~ /[^\s]/) {
		my %previous = &Apache::response::check_for_previous($response,
								    $part,$id);
		&Apache::lonxml::debug("submitted a $response<br>\n");
		&Apache::lonxml::debug($$parstack[-1] . "\n<br>");
		$Apache::lonhomework::results{"resource.$part.$id.submission"}=
		    $response;
		my ($ad,$msg);
		if ($type eq 're' ) { 
		    # if the RE wasn't in a var it likely got munged,
                    # thus grab it from the var directly
#		    my $testans=$token->[2]->{'answer'};
#		    if ($testans !~ m/^\s*\$/) {
#			$answer=$token->[2]->{'answer'};
#		    }
		    ${$safeeval->varglob('LONCAPA::response')}=$response;
		    $result = &Apache::run::run('if ($LONCAPA::response=~m'.$answer.') { return 1; } else { return 0; }',$safeeval);
		    &Apache::lonxml::debug("current $response");
		    &Apache::lonxml::debug("current $answer");
		    $ad = ($result) ? 'APPROX_ANS' : 'INCORRECT';
		} else {
		    my $args_ref= 
			\%{$safeeval->varglob('LONCAPA::CAPAresponse_args')};
		
		    $$args_ref{'response'}=$response;
		    &Apache::lonxml::debug("current $response");
		    $$args_ref{'type'}=
			&Apache::lonxml::get_param('type',$parstack,$safeeval);
		    foreach my $key (keys(%Apache::inputtags::params)) {
			$$args_ref{$key}=$Apache::inputtags::params{$key};
		    }
		    &Apache::lonxml::debug('answer is'.join(':',$answer));
		    @{$safeeval->varglob('LONCAPA::CAPAresponse_answer')}=($answer);
		    ($result, my @msgs)=&Apache::run::run("&caparesponse_check_list()",$safeeval);
		    &Apache::lonxml::debug('msgs are'.join(':',@msgs));
		    my ($awards)=split(/:/,$result);
		    my (@awards) = split(/,/,$awards);
		    ($ad,$msg) = &Apache::inputtags::finalizeawards(\@awards,\@msgs);
		    &Apache::lonxml::debug("\n<br>result:$result:$Apache::lonxml::curdepth<br>\n");
		}
		if ($Apache::lonhomework::type eq 'survey' &&
		    ($ad eq 'INCORRECT' || $ad eq 'APPROX_ANS' ||
		     $ad eq 'EXACT_ANS')) {
		    $ad='SUBMITTED';
		}
		&Apache::response::handle_previous(\%previous,$ad);
		$Apache::lonhomework::results{"resource.$part.$id.awarddetail"}=$ad;
		$Apache::lonhomework::results{"resource.$part.$id.awardmsg"}=$msg;
	    }
	}
    } elsif ($target eq 'answer' || $target eq 'analyze') {
	if ($target eq 'analyze') {
	    push (@{ $Apache::lonhomework::analyze{"parts"} },"$part.$id");
	    $Apache::lonhomework::analyze{"$part.$id.type"} = 'stringresponse';
	    &Apache::response::check_if_computed($token,$parstack,$safeeval,
						 'answer');
	}
	&Apache::response::setup_params('stringresponse',$safeeval);
	if ($target eq 'answer') {
	    $result.=&Apache::response::answer_header('stringresponse');
	}
#	foreach my $ans (@answers) {
	    if ($target eq 'answer') {
		$result.=&Apache::response::answer_part('stringresponse',$answer);
		if ($type eq 're') {
		    $result.=&Apache::response::answer_part('stringresponse',
							    $answerdisplay);
		}
	    } elsif ($target eq 'analyze') {
		push (@{ $Apache::lonhomework::analyze{"$part.$id.answer"} },
		      $answer);
	    }
#	}
	my $string='Case Insensitive';
	if ($type eq 'mc') {
	    $string='Multiple Choice';
	} elsif ($type eq 'cs') {
	    $string='Case Sensitive';
	} elsif ($type eq 'ci') {
	    $string='Case Insensitive';
	} elsif ($type eq 're') {
	    $string='Regular Expression';
	}
	if ($target eq 'answer') {
	    if ($env{'form.answer_output_mode'} eq 'tex') {
		$result.=&Apache::response::answer_part('stringresponse',
							"$string");
	    } else {
		$result.=&Apache::response::answer_part('stringresponse',
							"<b>$string</b>");
	    }
	} elsif ($target eq 'analyze') {
	    push (@{$Apache::lonhomework::analyze{"$part.$id.str_type"}},
		  $type);
	}
	if ($target eq 'answer') {
	    $result.=&Apache::response::answer_footer('stringresponse');
	}
    } elsif ($target eq 'edit') {
	$result.='</td></tr>'.&Apache::edit::end_table;
    }
    if ($target eq 'grade' || $target eq 'web' || $target eq 'answer' || 
	$target eq 'tex' || $target eq 'analyze') {
	&Apache::lonxml::increment_counter(&Apache::response::repetition());
    }
    &Apache::response::end_response;
    return $result;
}

sub start_formularesponse {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
    my $result;
    if ($target eq 'meta') {
	&Apache::response::start_response($parstack,$safeeval);
	$result=&Apache::response::meta_package_write('formularesponse');
	&Apache::response::end_response();
    } else {
	$result.=&start_numericalresponse(@_);
    }
    return $result;
}

sub end_formularesponse {
    return end_numericalresponse(@_);
}

sub start_mathresponse {
    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
    my $result;
    if ($target eq 'meta') {
        &Apache::response::start_response($parstack,$safeeval);
        $result=&Apache::response::meta_package_write('mathresponse');
        &Apache::response::end_response();
    } else {
        $result.=&start_numericalresponse(@_);
    }
    return $result;
}

sub end_mathresponse {
    return end_numericalresponse(@_);
}

1;
__END__


Index: modules/gerd/maxima/default_homework.lcpm
+++ modules/gerd/maxima/default_homework.lcpm
# The LearningOnline Network with CAPA 
# used by lonxml::xmlparse() as input variable $safeinit to Apache::run::run()
#
# $Id: default_homework.lcpm,v 1.1 2006/06/12 13:51:13 bisitz Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# LON-CAPA is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
#
#

#init some globals
$hidden::RANDOMINIT=0;
$pi=atan2(1,1)*4;
$rad2deg=180.0/$pi;
$deg2rad=$pi/180.0;
$"=' ';

sub check_commas {
    my ($response)=@_;
    #print("$response ");
    my @numbers=split(',',$response);
    #print(" numbers ".join('-',@numbers)." ");
    if (scalar(@numbers) > 1) {
        #print(" numbers[0] ".$numbers[0]." "); 
	if (length($numbers[0]) > 3 || length($numbers[0]) == 0) { return -1; }
	shift(@numbers);
	#print(" numbers ".scalar(@numbers)." ");
	while (scalar(@numbers) > 1) {
	    #print(" numbers ".join('-',@numbers)." ");
	    if (length($numbers[0]) != 3) { return -2; }
	    shift(@numbers);
	}
	my ($number)=split('\.',$numbers[0]);
	#print(" number ".$number." ");
	#print(" numbers[0] ".$numbers[0]." ");
	if (length($number) != 3) { return -3; }
    } else {
	my ($number)=split('\.',$numbers[0]);
	if (length($number) > 3) { return -4; }
    }
    return 1;
}

sub caparesponse_check {
    my ($answer,$response)=@_;
    #not properly used yet: calc
    #not to be used: $ans_fmt
    my $type=$LONCAPA::CAPAresponse_args{'type'};
    my $tol=$LONCAPA::CAPAresponse_args{'tol'};
    my $sig=$LONCAPA::CAPAresponse_args{'sig'};
    my $ans_fmt=$LONCAPA::CAPAresponse_args{'format'};
    my $unit=$LONCAPA::CAPAresponse_args{'unit'};
    my $calc=$LONCAPA::CAPAresponse_args{'calc'};
    my $samples=$LONCAPA::CAPAresponse_args{'samples'};
    
    my $tol_type=''; # gets it's value from whether tol has a % or not done
    my $sig_lbound=''; #done
    my $sig_ubound=''; #done


    #type's definitons come from capaParser.h
    my $message='';
    #remove leading and trailing whitespace
    if (!defined($response)) {
	$response='';
    }
    if ($response=~ /^\s|\s$/) {
	$response=~ s:^\s+|\s+$::g;
	$message .="Removed ws now :$response:\n";
    } else {
	$message .="no ws in :$response:\n";
    }
    &LONCAPA_INTERNAL_DEBUG(" type is $type ");
    if ($type eq 'cs' || $type eq 'ci') {
	#for string answers make surec all places spaces occur, there is 
        #really only 1 space, in both the answer and the response
	$answer=~s/ +/ /g;
	$response=~s/ +/ /g;
    } elsif ($type eq 'mc') {
	$answer=~s/[\s,]//g;
	$response=~s/[\s,]//g;
    }
    if ($type eq 'float' && $unit=~/\$/) {
	if ($response!~/^\$/)  { return "NO_UNIT: Missing \$ "; }
	$response=~s/\$//g;
    }
    if ($type eq 'float' && $unit=~/\,/ && (&check_commas($response)<0)) {
	return "COMMA_FAIL:";
    }
    $ans_fmt=~s/\W//g;
    $unit=~s/[\$,]//g;
    if ($type eq 'float') { $response=~s/,//g; }

    if (length($response) > 500) { return "TOO_LONG: Answer too long"; }

    if ($type eq '' ) {
	$message .= "Didn't find a type :$type: defaulting\n";
	if ( $answer eq ($answer *1.0)) { $type = 2;
				      } else { $type = 3; }
    } else {
	if ($type eq 'cs')    { $type = 4; }
	elsif ($type eq 'ci')    { $type = 3 }
	elsif ($type eq 'mc')    { $type = 5; }
	elsif ($type eq 'fml')   { $type = 8; }
        elsif ($type eq 'mth')   { $type = 9; }
	elsif ($type eq 'subj')  { $type = 7; }
	elsif ($type eq 'float') { $type = 2; }
	elsif ($type eq 'int')   { $type = 1; }
	else { return "ERROR: Unknown type of answer: $type" }
    }

    my $points;
    my $id_list;
    #formula type setup the sample points
    if ($type eq '8') {
	($id_list,$points)=split(/@/,$samples);
	$message.="Found :$id_list:$points: points in $samples\n";
    }
    if ($tol eq '') {
	$tol=0.0;
	$tol_type=1; #TOL_ABSOLUTE
    } else {
	if ($tol =~ /%$/) {
	    chop $tol;
	    $tol_type=2; #TOL_PERCENTAGE
	} else {
	    $tol_type=1; #TOL_ABSOLUTE
	}
    }

    ($sig_ubound,$sig_lbound)=&LONCAPA_INTERNAL_get_sigrange($sig);

    my $reterror="";
    my $result;
    if ($type eq '9') {
      $result = &maxima_check($response,$answer,$type,
                                                 $tol_type,$tol,
                                                 $sig_lbound,$sig_ubound,
                                                 $ans_fmt,$unit,$calc,$id_list,
                                                 $points,$external::randomseed,
                                                 \$reterror);
    } else {
       $result = &caparesponse_capa_check_answer($response,$answer,$type,
						 $tol_type,$tol,
						 $sig_lbound,$sig_ubound,
						 $ans_fmt,$unit,$calc,$id_list,
						 $points,$external::randomseed,
						 \$reterror);
    }
    if    ($result == '1') { $result='EXACT_ANS'; } 
    elsif ($result == '2') { $result='APPROX_ANS'; }
    elsif ($result == '3') { $result='SIG_FAIL'; }
    elsif ($result == '4') { $result='UNIT_FAIL'; }
    elsif ($result == '5') { $result='NO_UNIT'; }
    elsif ($result == '6') { $result='UNIT_OK'; }
    elsif ($result == '7') { $result='INCORRECT'; }
    elsif ($result == '8') { $result='UNIT_NOTNEEDED'; }
    elsif ($result == '9') { $result='ANS_CNT_NOT_MATCH'; }
    elsif ($result =='10') { $result='SUB_RECORDED'; }
    elsif ($result =='11') { $result='BAD_FORMULA'; }
    elsif ($result =='12' && !$response) { $result='MISSING_ANSWER'; }
    elsif ($result =='12') { $result='WANTED_NUMERIC'; }
    elsif ($result =='13') { $result='UNIT_INVALID_INSTRUCTOR'; }
    elsif ($result =='141') { $result='UNIT_INVALID_STUDENT'; }
    elsif ($result =='142') { $result='UNIT_INVALID_STUDENT'; }
    elsif ($result =='143') { $result='UNIT_INVALID_STUDENT'; }
    elsif ($result =='15') { $result='UNIT_IRRECONCIBLE'; }
    else  {$result = "ERROR: Unknown Result:$result:$@:";}

    return ("$result:\nRetError $reterror:\nAnswer $answer:\nResponse $response:\n type-$type|$tol|$tol_type|$sig:$sig_lbound:$sig_ubound|$unit|\n$message",$reterror);
}


sub caparesponse_check_list {
    my $response=$LONCAPA::CAPAresponse_args{'response'};
    my $result="Got response :".join(':',@LONCAPA::CAPAresponse_answer).":\n";
    &LONCAPA_INTERNAL_DEBUG("args ".join(':',%LONCAPA::CAPAresponse_args));
    my @responselist;
    my $type = $LONCAPA::CAPAresponse_args{'type'};
    $result.="Got type :$type:\n";
    if ($type ne '' && $#LONCAPA::CAPAresponse_answer > 0) {
	(@responselist)=split(/,/,$response);
	if (@responselist < @LONCAPA::CAPAresponse_answer) {
	    return 'MISSING_ANSWER';
	}
	if (@responselist > @LONCAPA::CAPAresponse_answer) {
	    return 'EXTRA_ANSWER';
	}
    } else {
	(@responselist)=($response);
    }
    $result.="Initial final response :$responselist['-1']:\n";
    my $unit;
    if ($type eq '' || $type eq 'float') {
	#for numerical problems split off the unit
	if ( $responselist['-1']=~ /(.*[^\s])\s+([^\s]+)/ ) {
	    $responselist['-1']=$1;
	    $unit=$2;
	}
    }
    $result.="Final final response :$responselist['-1']:$unit:\n";
    $unit=~s/\s//;

    my ($awards, @msgs, $i);
    foreach my $thisanswer (@LONCAPA::CAPAresponse_answer) {
	my ($msg,$aresult);
	$result.="trying answer :$thisanswer:\n";
	if (defined($thisanswer)) {
	    if ($unit eq '') {
		($aresult,$msg)=&caparesponse_check($thisanswer,
						    $responselist[$i]);
	    } else {
		($aresult,$msg)=&caparesponse_check($thisanswer,
						    $responselist[$i]." $unit");
	    }
	} else {
	    $aresult='ERROR';
	    $msg='answer was undefined';
	}
	&LONCAPA_INTERNAL_DEBUG("after if $aresult -- $msg");
	my ($temp)=split(/:/, $aresult);
	$awards.="$temp,";
	$result.=$aresult;
	push(@msgs,$msg);
	$i++;
    }
    chop($awards);
    return ("$awards:\n$result",@msgs);
}

sub tex {
    if ( $external::target eq "tex" ) {
	return $_[0];
    } else {
	return $_[1];
    }
}

sub var_in_tex {
    if ( $external::target eq "tex" ) {
	return $_[0];
    } else {
	return "";
    }
}

sub web {
    if ( $external::target eq "tex" ) {
	return $_[1];
    } else {
	if ( $external::target eq "web" || $external::target eq "answer") {
	    return $_[2];
	} else {
	    return $_[0];
	}
    }
}

sub html {
    if ( $external::target eq "web" ) {
	return shift;
    }
}

sub hinton {
    return 0;
}

sub random {
    my ($start,$end,$step)=@_;
    if ( ! $hidden::RANDOMINIT ) {
	if ($external::randomseed == 0) { $external::randomseed=1; }
	if ($external::randomseed =~/,/) {
	    my ($num1,$num2)=split(/,/,$external::randomseed);
	    &random_set_seed(1,abs($num1));
	} elsif ($external::randomseed =~/:/) {
	    my ($num1,$num2)=split(/:/,$external::randomseed);
	    &random_set_seed(abs($num1),abs($num2));
	} else {
	    &random_set_seed(1,int(abs($external::randomseed)));
	}
	&math_random_uniform();
	$hidden::RANDOMINIT=1;
    }
    if (!defined($step)) { $step=1; }
    my $num=1+int(($end-$start)/$step);
    my $result=$start + int(&math_random_uniform() * $num)*$step;
    return $result;
}

sub random_normal {
    my ($item_cnt,$seed,$av,$std_dev) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    @retArray=&math_random_normal($item_cnt,$av,$std_dev);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_beta {
    my ($item_cnt,$seed,$aa,$bb) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    @retArray=&math_random_beta($item_cnt,$aa,$bb);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_gamma {
    my ($item_cnt,$seed,$a,$r) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    @retArray=&math_random_gamma($item_cnt,$a,$r);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_exponential {
    my ($item_cnt,$seed,$av) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    @retArray=&math_random_exponential($item_cnt,$av);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_poisson {
    my ($item_cnt,$seed,$mu) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    @retArray=&math_random_poisson($item_cnt,$mu);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_chi {
    my ($item_cnt,$seed,$df) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    @retArray=&math_random_chi_square($item_cnt,$df);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_noncentral_chi {
    my ($item_cnt,$seed,$df,$nonc) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    @retArray=&math_random_noncentral_chi_square($item_cnt,$df,$nonc);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_f {
    my ($item_cnt,$seed,$dfn,$dfd) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    @retArray=&math_random_f($item_cnt,$dfn,$dfd);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_noncentral_f {
    my ($item_cnt,$seed,$dfn,$dfd,$nonc) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    @retArray=&math_random_noncentral_f($item_cnt,$dfn,$dfd,$nonc);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_multivariate_normal {
    my ($item_cnt,$seed,$mean,$covar) = @_;
    my @oldseed=&random_get_seed();
    &random_set_seed_from_phrase($seed);
    my @retArray=&math_random_multivariate_normal($item_cnt,@$mean,@$covar);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_multinomial {
    my ($item_cnt,$seed,@p) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    my @retArray=&math_random_multinomial($item_cnt,@p);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_permutation {
    my ($seed,@inArray) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    @retArray=&math_random_permutation(@inArray);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_uniform {
    my ($item_cnt,$seed,$low,$high) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    @retArray=&math_random_uniform($item_cnt,$low,$high);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_uniform_integer {
    my ($item_cnt,$seed,$low,$high) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    @retArray=&math_random_uniform_integer($item_cnt,$low,$high);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_binomial {
    my ($item_cnt,$seed,$nt,$p) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    @retArray=&math_random_binomial($item_cnt,$nt,$p);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub random_negative_binomial {
    my ($item_cnt,$seed,$ne,$p) = @_;
    my @oldseed=&random_get_seed();
    my @retArray;
    &random_set_seed_from_phrase($seed);
    @retArray=&math_random_negative_binomial($item_cnt,$ne,$p);
    &random_set_seed(@oldseed);
    return @retArray;
}

sub abs { CORE::abs(shift) }
sub sin { CORE::sin(shift) }
sub cos { CORE::cos(shift) }
sub exp { CORE::exp(shift) }
sub int { CORE::int(shift) }
sub log { CORE::log(shift) }
sub atan2 { CORE::atan2($_[0],$_[1]) }
sub sqrt { CORE::sqrt(shift) }

sub tan  { CORE::sin($_[0]) / CORE::cos($_[0]) }
#sub atan { atan2($_[0], 1); }
#sub acos { atan2(sqrt(1 - $_[0] * $_[0]), $_[0] ); }
#sub asin { atan2($_[0], sqrt(1- $_[0] * $_[0]) );  }

sub log10 { CORE::log($_[0])/CORE::log(10); }

sub factorial {
    my $input = CORE::int(shift);
    return "Error - unable to take factorial of an negative number ($input)" if $input < 0;
    return "Error - factorial result is greater than system limit ($input)" if $input > 170;
    return 1 if $input == 0;
    my $result = 1; 
    for (my $i=2; $i<=$input; $i++) { $result *= $i }
    return $result;
}

sub sgn {
    return -1 if $_[0] < 0;
    return 0 if $_[0] == 0;
    return 1 if $_[0] > 0;
}

sub min {
    my @sorted = sort { $a <=> $b || $a cmp $b } @_;
    return shift @sorted;
}

sub max {
    my @sorted = sort { $a <=> $b || $a cmp $b } @_;
    return pop @sorted;
}

sub roundto {
    my ($input,$n) = @_;
    return sprintf('%.'.$n.'f',$input);
}

sub to_string {
    my ($input,$n) = @_;
    return sprintf($input) if $n eq "";
    $n = '.'.$n if $n !~ /^\./;
    return sprintf('%'.$n,$input) if $n ne "";
}

sub sub_string {
    my ($str,$start,$len) = @_;
    return substr($str,$start-1,$len);
}

sub pow   {return $_[0] ** $_[1]; }
sub ceil  {return (($_[0]-CORE::int($_[0]))== 0.0) ? $_[0] : (($_[0] > 0) ? (CORE::int($_[0])+ 1) : CORE::int($_[0])); }
sub floor  {return (($_[0]-CORE::int($_[0]))== 0.0) ? $_[0] : (($_[0] > 0) ? CORE::int($_[0]) : (CORE::int($_[0])-1)); }
#sub floor {return int($_[0]); }

sub format {
    my ($value,$fmt)=@_;
    my ($dollarmode,$commamode,$alwaysperiod,$options);
    if ($fmt =~ /^([^\d]*)(.*)/) { $options=$1; $fmt=$2; } 
    #if ($options =~ /\$/) { $dollamode=1; }
    #if ($options =~ /,/)  { $commamode=1; }
    if ($options =~ /\./) { $alwaysperiod=1; }
    my $result;
    if ($fmt=~/s$/i) {
	$result=&format_significant_figures($value,$fmt);
    } else {
	$fmt=~s/e/E/g;
	$result=sprintf('%.'.$fmt,$value);
	if ($alwaysperiod && $fmt eq '0f') { $result .='.'; }
	$result=~s/(E[+-]*)0/$1/;
    }
    #if ($dollarmode) {$result=&dollarformat($result);}
    #if ($commamode) {$result=&commaformat($result);}
    return $result;
}

sub chemparse {
    my ($reaction) = @_;
    my @tokens = split(/(\s\+|\->|<=>|<\-|\.)/,$reaction);
    my $formula = '';
    foreach my $token (@tokens) {
	if ($token eq '->' ) {
	    $formula .= '<m>\ensuremath{\rightarrow}</m> ';
	    next;
	}
	if ($token eq '<-' ) {
	    $formula .= '<m>\ensuremath{\leftarrow}</m> ';
	    next;
	}  
	if ($token eq '<=>') {
	    if ($external::target eq 'web' &&
		&EXT('request.browser.unicode')) {
		$formula .= '&#8652; ';
	    } else {
		$formula .= &web('<=> ','<m>\ensuremath{\rightleftharpoons}</m> ',
				 '&lt;=&gt; ');
	    }
	    next;
	}
	if ($token eq '.') {
	  $formula =~ s/(\&nbsp\;| )$//;
	  $formula .= '&middot;';
	  next;
	}
	$token =~ /^\s*([\d|\/]*(?:&frac\d\d)?)(.*)/;
        $formula .= $1 if ($1 ne '1');  # stoichiometric coefficient
	
	my $molecule = $2;
	# subscripts
	$molecule =~ s|(?<=[a-zA-Z\)\]\s])(\d+)|<sub>$1</sub>|g;
	# superscripts
	$molecule =~ s|\^(\d*[+\-]*)|<sup>$1</sup>|g;
	# strip whitespace
	$molecule =~ s/\s*//g;
	# forced space
	$molecule =~ s/_/ /g;
	$molecule =~ s/-/&minus;/g;
	$formula .= $molecule.'&nbsp;';
    }
    # get rid of trailing space
    $formula =~ s/(\&nbsp\;| )$//;
    return &xmlparse($formula);
}

sub prettyprint {
    my ($value,$fmt,$target)=@_;
    my $result;
    if (!$target) { $target = $external::target; }
    if ($fmt =~ /chem/i) { return(&chemparse($value)); }
    my ($dollarmode,$commamode,$alwaysperiod,$options);
    if ($fmt =~ /^([^\d]*)(.*)/) { $options=$1; $fmt=$2; } 
    if ($options =~ /\$/) { $dollarmode=1; }
    if ($options =~ /,/)  { $commamode=1; }
    if ($options =~ /\./) { $alwaysperiod=1; }
    if ($fmt=~/s$/i) {
	$value=&format_significant_figures($value,$fmt);
    } elsif ($fmt) {
	$value=sprintf('%.'.$fmt,$value);
    }
    if ($alwaysperiod && $fmt eq '0f') {
	if ($target eq 'tex') {
	    $value .='\\ensuremath{.}';
	} else {
	    $value .='.';
	}
    }
    if ($value =~ /([0-9\.\-\+]+)E([0-9\-\+]+)/i ) {
	my $frac=$1;
	if ($dollarmode) { $frac=&dollarformat($frac); }
	if ($commamode) { $frac=&commaformat($frac); }
	my $exponent=$2;
	$exponent=~s/^\+0*//;
	$exponent=~s/^-0*/-/;
	$exponent=~s/^-0*/-/;
	if ($exponent eq '-') { undef($exponent); }
	if ($exponent) {
	    if ($target eq 'web') {
		$result=$frac.'&#215;10<sup>'.$exponent.'</sup>';
	    } elsif ($target eq 'tex') {
		$result='\ensuremath{'.$frac.'\times 10^{'.$exponent.'}}';
	    } else {
		$result=$value;
	    }
	} else {
	    $result=$frac;
	}
    } else {
	$result=$value;
	if    ($dollarmode) { $result=&dollarformat($result,$target); }
	elsif ($commamode)  { $result=&commaformat($result,$target); }
    }
    return $result;
}

sub commaformat {
    my ($number,$target) = @_;
    if ($number =~ /\./) {
	while ($number =~ /([^0-9]*)([0-9]+)([^\.,][^\.,][^\.,])([,0-9]*\.[0-9]*)$/) {
	    $number = $1.$2.','.$3.$4;
	}
    } else {
	while ($number =~ /^([^0-9]*)([0-9]+)([^,][^,][^,])([,0-9]*)$/) {
	    $number = $1.$2.','.$3.$4;
	}
    }
    return $number;
}

sub dollarformat {
    my ($number,$target) = @_;
    if (!$target) { $target = $external::target; }
    $number=&commaformat($number,$target);
    if ($target eq 'tex') {
	$number='\$'.$number; #' stupid emacs
    } else {
	$number='$'.$number; #' stupid emacs
    }
    return $number; 
}

# format of form ns or nS where n is an integer
sub format_significant_figures {
    my ($number,$format) = @_; 
    return '0' if ($number == 0);
    # extract number of significant figures needed
    my ($sig) = ($format =~ /(\d+)s/i);
    # arbitrary choice - suggestions ?? or throw error message?
    $sig = 3 if ($sig eq '');
    # save the minus sign
    my $sign = ($number < 0) ? '-' : '';
    $number = abs($number);
    # needed to correct for a number greater than 1 (or
    my $power = ($number < 1) ? 0 : 1;
    # could round up. Take the integer part of log10.
    my $x10 = int(log($number)/log(10));
    # find number with values left of decimal pt = # of sign figs.
    my $xsig = $number*10**($sig-$x10-$power);
    # get just digits left of decimal pt - also rounds off correctly
    my $xint  = sprintf('%.0f',$xsig);
    # save any trailing zero's
    my ($zeros) = ($xint =~ /(0+)$/);
    # return number to original magnitude
    my $numSig = $xint*10**($x10-$sig+$power);
    # insert trailing zero's if have decimal point
    $numSig =~ s/^(\d+)\.(\d+)(\e?(.*)?)$/$1\.$2$zeros$3/;
    # put a decimal pt for number ending with 0 and length = # of sig fig
    $numSig.='.' if (length($numSig) == $sig && $numSig =~ /0$/);
    if (length($numSig) < $sig) {
	$numSig.='.'.substr($zeros,0,($sig-length($numSig)));
    }
    # return number with sign
    return $sign.$numSig;

}

sub map {
    my ($phrase,$dest,$source)=@_;
    my @oldseed=&random_get_seed();
    my @seed = &random_seed_from_phrase($phrase);
    &random_set_seed(@seed);
    my $destct = scalar(@$dest);
    if (!$source) {
	my @output;
	my @idx = &math_random_permuted_index($destct);
	my $ctr = 0;
	while ($ctr < $destct) {
	    $output[$ctr] = $$dest[$idx[$ctr]];
	    $ctr++;
	}
        &random_set_seed(@oldseed);
	return @output;
    } else {
	my $num = scalar(@$source);
	my @idx = &math_random_permuted_index($num);
	my $ctr = 0;
	my $tot = $num;
	$tot = $destct if $destct < $num;
	if (ref($$dest[0])) {
	    while ($ctr < $tot) {
		${$$dest[$ctr]} = $$source[$idx[$ctr]];
	        $ctr++;
            }
        } else {
	    while ($ctr < $tot) {
		$$dest[$ctr] = $$source[$idx[$ctr]];
		$ctr++;
	    }
	}
    }
    &random_set_seed(@oldseed);
    return '';
}

sub rmap {
    my ($phrase,$dest,$source)=@_;
    my @oldseed=&random_get_seed();
    my @seed = &random_seed_from_phrase($phrase);
    &random_set_seed(@seed);
    my $destct = scalar(@$dest);
    if (!$source) {
	my @idx = &math_random_permuted_index($destct);
	my $ctr = 0;
	my @r_idx;
	while ($ctr < $destct) {
	    $r_idx[$idx[$ctr]] = $ctr;
	    $ctr++;
	}
	my @output;
	$ctr = 0;
	while ($ctr < $destct) {
	    $output[$ctr] = $$dest[$r_idx[$ctr]];
	    $ctr++;
	}
        &random_set_seed(@oldseed);
	return @output;
    } else {
	my $num = scalar(@$source);
	my @idx = &math_random_permuted_index($num);
	my $ctr = 0;
	my $tot = $num;
	$tot = $destct if $destct < $num;
	my @r_idx;
	while ($ctr < $tot) {
	    $r_idx[$idx[$ctr]] = $ctr;
	    $ctr++;
	}
	$ctr = 0;
	if (ref($$dest[0])) {
	    while ($ctr < $tot) {
		${$$dest[$ctr]} = $$source[$r_idx[$ctr]];
	        $ctr++;
            }
        } else {
	    while ($ctr < $tot) {
		$$dest[$ctr] = $$source[$r_idx[$ctr]];
		$ctr++;
	    }
	}
    }
    &random_set_seed(@oldseed);
    return '';
}

sub capa_id { return }

sub problem { return }

sub name{
    my $fullname = &EXT('environment.lastname').', '.&EXT('environment.firstname').' '.&EXT('environment.middlename');
    $fullname = "" if $fullname eq ",  ";
    $fullname =~ s/\%2d/-/g;
    return $fullname;
}

sub student_number { 
    my $id = &EXT('environment.id');
    $id = '' if $id eq "";
    return $id;
}

sub class {
    my $course = &EXT('course.description');
    $course = '' if $course eq "";
    return $course;
}

sub sec { 
    my $sec = &EXT('request.course.sec');
    $sec = '' if $sec eq "";
    return $sec;
}

sub open_date { 
    my @dc = split(/\s+/,localtime(&EXT('resource.0.opendate')));
    return '' if ($dc[0] eq "Wed" and $dc[2] == 31 and $dc[4] == 1969);
    my @hm = split(/:/,$dc[3]);
    my $ampm = " am";
    if ($hm[0] > 12) {
	$hm[0]-=12;
	$ampm = " pm";
    }
    return $dc[0].', '.$dc[1].' '.$dc[2].', '.$dc[4].' at '.$hm[0].':'.$hm[1].$ampm;
}

sub due_date { 
    my @dc = split(/\s+/,localtime(&EXT('resource.0.duedate')));
    return '' if ($dc[0] eq "Wed" and $dc[2] == 31 and $dc[4] == 1969);
    my @hm = split(/:/,$dc[3]);
    my $ampm = " am";
    if ($hm[0] > 12) {
	$hm[0]-=12;
	$ampm = " pm";
    }
    return $dc[0].', '.$dc[1].' '.$dc[2].', '.$dc[4].' at '.$hm[0].':'.$hm[1].$ampm;
}

sub answer_date { 
    my @dc = split(/\s+/,localtime(&EXT('resource.0.answerdate')));
    return '' if ($dc[0] eq "Wed" and $dc[2] == 31 and $dc[4] == 1969);
    my @hm = split(/:/,$dc[3]);
    my $ampm = " am";
    if ($hm[0] > 12) {
	$hm[0]-=12;
	$ampm = " pm";
    }
    return $dc[0].', '.$dc[1].' '.$dc[2].', '.$dc[4].' at '.$hm[0].':'.$hm[1].$ampm;
}

sub array_moments {
    my @input=@_;
    my (@output,$N);
    $N=scalar (@input);
    $output[0]=$N;
    if ($N <= 1) {
	$output[1]=$input[0];
	$output[1]="Input array not defined" if ($N == 0);
	$output[2]="variance undefined for N<=1";
	$output[3]="skewness undefined for N<=1";
	$output[4]="kurtosis undefined for N<=1";
	return @output;
    }
    my $sum=0;
    foreach my $line (@input) {
	$sum+=$line;
    }
    $output[1] = $sum/$N;
    my ($x,$sdev,$var,$skew,$kurt) = 0;
    foreach my $line (@input) {
	$x=$line-$output[1];
	$var+=$x**2;
	$skew+=$x**3;
	$kurt+=$x**4;
    }
    $output[2]=$var/($N-1);
    $sdev=CORE::sqrt($output[2]);
    if ($sdev == 0) {
	$output[3]="inf-variance=0";
	$output[4]="inf-variance=0";
	return @output;
    }
    $output[3]=$skew/($sdev**3*$N);
    $output[4]=$kurt/($sdev**4*$N)-3;
    return @output;
}

sub choose {
    my $num = $_[0];
    return $_[$num];
}

#&sum1(1,$x,sub { &sum1($_[0],2*$_[0], sub { fact($_[0])**2 })});
#sub sum1 {
#    my ($start,$end,$sub)=@_;
#    my $sum=0;
#    for (my $i=$start;$i<=$end;$i++) {
#        $sum+=&$sub($i);
#    }
#    return $sum
#}

#&sum2('a',1,$x,'&sum2(\'b\',$a,2*$a, \'&factorial($b)**2\')');
#sub sum2 {
#    my ($varname,$start,$end,$line)=@_;
#    my $sum=0;
#    for (my $i=$start;$i<=$end;$i++) {
#	my $func=sub {
#	    eval("\$".$varname."=$i");
#	    eval($line);
#	};
#        $sum+=&$func($i);
#    }
#    return $sum
#}

# expiremental idea
sub proper_path {
    my ($path)=@_;
    if ( $external::target eq "tex" ) {
	return '/home/httpd/html'.$path;
    } else {
	return $path;
    }
}


--bisitz1150120277--