--- loncom/homework/default_homework.lcpm	2004/03/26 20:10:42	1.77
+++ loncom/homework/default_homework.lcpm	2005/06/17 20:24:56	1.100
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA 
 # used by lonxml::xmlparse() as input variable $safeinit to Apache::run::run()
 #
-# $Id: default_homework.lcpm,v 1.77 2004/03/26 20:10:42 albertel Exp $
+# $Id: default_homework.lcpm,v 1.100 2005/06/17 20:24:56 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -34,6 +34,32 @@ $rad2deg=180.0/$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
@@ -41,7 +67,7 @@ sub caparesponse_check {
     my $type=$LONCAPA::CAPAresponse_args{'type'};
     my $tol=$LONCAPA::CAPAresponse_args{'tol'};
     my $sig=$LONCAPA::CAPAresponse_args{'sig'};
-    my $ans_fmt=$LONCAPA::CAPAresponse_args{'ans_fmt'};
+    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'};
@@ -63,12 +89,27 @@ sub caparesponse_check {
     } else {
 	$message .="no ws in :$response:\n";
     }
-    if ($type eq 'cs' || $type eq 'ci' || $type eq 'mc') {
+    &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 '' ) {
@@ -105,17 +146,8 @@ sub caparesponse_check {
 	}
     }
 
-    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; }
-    }
+    ($sig_ubound,$sig_lbound)=&LONCAPA_INTERNAL_get_sigrange($sig);
+
     my $reterror="";
     my $result = &caparesponse_capa_check_answer($response,$answer,$type,
 						 $tol_type,$tol,
@@ -135,6 +167,8 @@ sub caparesponse_check {
     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') { $result='UNIT_INVALID_STUDENT'; }
@@ -142,7 +176,7 @@ sub caparesponse_check {
     elsif ($result =='15') { $result='UNIT_IRRECONCIBLE'; }
     else  {$result = "ERROR: Unknown Result:$result:$@:";}
 
-    return ("$result:\nRetError $reterror:\nError $error:\nAnswer $answer:\nResponse $response:\n type-$type|$tol|$tol_type|$sig:$sig_lbound:$sig_ubound|$unit|\n$message",$reterror);
+    return ("$result:\nRetError $reterror:\nAnswer $answer:\nResponse $response:\n type-$type|$tol|$tol_type|$sig:$sig_lbound:$sig_ubound|$unit|\n$message",$reterror);
 }
 
 
@@ -172,7 +206,7 @@ sub caparesponse_check_list {
 	    $unit=$2;
 	}
     }
-    $result.="Final final response :$responselist['-1']:\n";
+    $result.="Final final response :$responselist['-1']:$unit:\n";
     $result.=":$#list: answers\n";
     $unit=~s/\s//;
     my $i=0;
@@ -241,7 +275,10 @@ sub random {
     if ( ! $hidden::RANDOMINIT ) {
 	if ($external::randomseed == 0) { $external::randomseed=1; }
 	if ($external::randomseed =~/,/) {
-	    my ($num1,$num2)=split(/,/,$seed);
+	    my ($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)));
@@ -349,7 +386,7 @@ sub random_multivariate_normal {
     my ($item_cnt,$seed,$mean,$covar) = @_;
     my @oldseed=&random_get_seed();
     &random_set_seed_from_phrase($seed);
-    @retArray=&math_random_multivariate_normal($item_cnt,@$mean,@$covar);
+    my @retArray=&math_random_multivariate_normal($item_cnt,@$mean,@$covar);
     &random_set_seed(@oldseed);
     return @retArray;
 }
@@ -359,7 +396,7 @@ sub random_multinomial {
     my @oldseed=&random_get_seed();
     my @retArray;
     &random_set_seed_from_phrase($seed);
-    @retArray=&math_random_multinomial($item_cnt,@p);
+    my @retArray=&math_random_multinomial($item_cnt,@p);
     &random_set_seed(@oldseed);
     return @retArray;
 }
@@ -480,65 +517,99 @@ sub floor  {return (($_[0]-CORE::int($_[
 
 sub format {
     my ($value,$fmt)=@_;
-    my $dollarmode;
-    if ($fmt =~ /^\$(.*)/) { $fmt=$1; $dollarmode=1; } 
-    $fmt=~s/e/E/g;
-    my $result=sprintf('%.'.$fmt,$value);
-    $result=~s/(E[+-]*)0/$1/;
-    if ($dollarmode) {$result=&dollarmode($result);}
+    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 @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; ');
+				 '&lt;=&gt; ');
 	    }
 	    next;
 	}
-	$token =~ /^\s*(\d*)(.*)/;
-	$formula .= $1 if ($1 > 1);  # stoichiometric coefficient
+	if ($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;
+	$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
-    $formula =~ s/(\Q${nbsp}\E| )$//;
-    
+    $formula =~ s/(\&nbsp\;| )$//;
     return &xmlparse($formula);
 }
 
 sub prettyprint {
     my ($value,$fmt,$target)=@_;
     my $result;
-    my $dollarmode;
     if (!$target) { $target = $external::target; }
     if ($fmt =~ /chem/i) { return(&chemparse($value)); }
-    if ($fmt =~ /^\$(.*)/) { $fmt=$1; $dollarmode=1; } 
-    if ($fmt) { $value=sprintf('%.'.$fmt,$value); }
+    my ($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*/-/;
@@ -557,14 +628,14 @@ sub prettyprint {
 	}
     } else {
 	$result=$value;
-	if ($dollarmode) { $result=&dollarformat($result,$target); }
+	if    ($dollarmode) { $result=&dollarformat($result,$target); }
+	elsif ($commamode)  { $result=&commaformat($result,$target); }
     }
     return $result;
 }
 
-sub dollarformat {
+sub commaformat {
     my ($number,$target) = @_;
-    if (!$target) { $target = $external::target; }
     if ($number =~ /\./) {
 	while ($number =~ /([^\.,]+)([^\.,][^\.,][^\.,])([,0-9]*\.[0-9]*)$/) {
 	    $number = $1.','.$2.$3;
@@ -574,6 +645,13 @@ sub dollarformat {
 	    $number = $1.','.$2.$3;
 	}
     }
+    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 {
@@ -582,6 +660,41 @@ sub dollarformat {
     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();