--- loncom/homework/default_homework.lcpm	2002/02/06 16:18:26	1.46
+++ loncom/homework/default_homework.lcpm	2002/09/26 20:45:00	1.51
@@ -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 1.46 2002/02/06 16:18:26 albertel Exp $
+# $Id: default_homework.lcpm,v 1.51 2002/09/26 20:45:00 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -240,139 +240,171 @@ sub hinton {
 sub random {
   my ($start,$end,$step)=@_;
   if ( ! $hidden::RANDOMINIT ) {
-    srand($external::randomseed);
+    &random_set_seed_from_phrase($external::randomseed);
     $hidden::RANDOMINIT=1;
   }
   if (!defined($step)) { $step=1; }
   my $num=1+int(($end-$start)/$step);
-  my $result=$start + int(rand() * $num)*$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($seed);
   @retArray=&math_random_multivariate_normal($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($seed);
   @retArray=&math_random_multinomial($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;
 }
 
@@ -442,32 +474,66 @@ sub floor  {return (($_[0]-int($_[0]))==
 
 sub format {
   my ($value,$fmt)=@_;
-  return sprintf('%.'.$fmt,$value);
+  my $dollarmode;
+  if ($fmt =~ /^\$(.*)/) { $fmt=$1; $dollarmode=1; } 
+  my $result=sprintf('%.'.$fmt,$value);
+  $result=~s/(E[+-]*)0/$1/;
+  if ($dollarmode) {$result=&dollarmode($result);}
+  return $result;
 }
 
 sub prettyprint {
   my ($value,$fmt)=@_;
   my $result;
+  my $dollarmode;
+  if ($fmt =~ /^\$(.*)/) { $fmt=$1; $dollarmode=1; } 
   if ($fmt) { $value=sprintf('%.'.$fmt,$value); }
   if ($value =~ /([0-9\.\-\+]+)E([0-9\-\+]+)/ ) {
     my $frac=$1;
+    if ($dollarmode) { $frac=&dollarformat($frac); }
     my $exponent=$2;
     $exponent=~s/^\+0*//;
-    if ($external::target eq 'web') {
-      $result=$frac.'&#215;10<sup>'.$exponent.'</sup>';
-    } elsif ($external::target eq 'tex') {
-      $result='\ensuremath{'.$frac.'\times 10^{'.$exponent.'}}';
+    $exponent=~s/^-0*/-/;
+    if ($exponent) {
+      if ($external::target eq 'web') {
+	$result=$frac.'&#215;10<sup>'.$exponent.'</sup>';
+      } elsif ($external::target eq 'tex') {
+	$result='\ensuremath{'.$frac.'\times 10^{'.$exponent.'}}';
+      } else {
+	$result=$value;
+      }
     } else {
-      $result=$value;
+      $result=$frac;
     }
   } else {
     $result=$value;
+    if ($dollarmode) { $result=&dollarformat($result); }
   }
   return $result;
 }
 
+sub dollarformat {
+  my ($number) = @_;
+  if ($number =~ /\./) {
+    while ($number =~ /([^\.,]+)([^\.,][^\.,][^\.,])([,0-9]*\.[0-9]*$)/) {
+      $number = $1.','.$2.$3;
+    }
+  } else {
+    while ($number =~ /([^,]+)([^,][^,][^,])([,0-9]*)$/) {
+      $number = $1.','.$2.$3;
+    }
+  }
+  if ($external::target eq 'tex') {
+    $number='\$'.$number; #' stupid emacs
+  } else {
+    $number='$'.$number; #' stupid emacs
+  }
+  return $number; 
+}
+
 sub map {
     my ($phrase,$dest,$source)=@_;
+    my @oldseed=&random_get_seed();
     my @seed = &random_seed_from_phrase($phrase);
     &random_set_seed(@seed);
     my $destct = scalar(@$dest);
@@ -479,6 +545,7 @@ sub map {
 	    $output[$ctr] = $$dest[$idx[$ctr]];
 	    $ctr++;
 	}
+        &random_set_seed(@oldseed);
 	return @output;
     } else {
 	my $num = scalar(@$source);
@@ -498,10 +565,13 @@ sub map {
 	    }
 	}
     }
+    &random_set_seed(@seed);
+    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);
@@ -519,6 +589,7 @@ sub rmap {
 	    $output[$ctr] = $$dest[$r_idx[$ctr]];
 	    $ctr++;
 	}
+        &random_set_seed(@oldseed);
 	return @output;
     } else {
 	my $num = scalar(@$source);
@@ -544,6 +615,8 @@ sub rmap {
 	    }
 	}
     }
+    &random_set_seed(@oldseed);
+    return '';
 }
 
 sub capa_id { return }
@@ -655,4 +728,13 @@ sub choose {
   return $_[$num];
 }
 
+# expiremental idea
+sub proper_path {
+  my ($path)=@_;
+  if ( $external::target eq "tex" ) {
+    return '/home/httpd/html'.$path;
+  } else {
+    return $path;
+  }
+}