--- loncom/homework/default_homework.lcpm	2002/05/31 22:19:06	1.47
+++ loncom/homework/default_homework.lcpm	2002/07/17 18:08:39	1.48
@@ -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 1.47 2002/05/31 22:19:06 albertel Exp $
+# $Id: default_homework.lcpm,v 1.48 2002/07/17 18:08:39 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -442,31 +442,61 @@ 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,$value);
+  if ($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;
     $exponent=~s/^\+0*//;
-    if (!$exponent) { return $frac; }
-    if ($external::target eq 'web') {
-      $result=$frac.'&#215;10<sup>'.$exponent.'</sup>';
-    } elsif ($external::target eq 'tex') {
-      $result='\ensuremath{'.$frac.'\times 10^{'.$exponent.'}}';
+    if ($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 @seed = &random_seed_from_phrase($phrase);