--- loncom/homework/default_homework.lcpm	2001/06/12 21:07:32	1.26
+++ loncom/homework/default_homework.lcpm	2001/06/14 21:29:14	1.28
@@ -358,8 +358,9 @@ sub sub_string {
 }
 
 sub pow   {return $_[0] ** $_[1]; }
-sub ceil  {return (($_[0]-int($_[0]))== 0.0) ? $_[0] : (int($_[0])+ 1); }
-sub floor {return int($_[0]);  }
+sub ceil  {return (($_[0]-int($_[0]))== 0.0) ? $_[0] : (($_[0] > 0) ? (int($_[0])+ 1) : int($_[0])); }
+sub floor  {return (($_[0]-int($_[0]))== 0.0) ? $_[0] : (($_[0] > 0) ? int($_[0]) : (int($_[0])-1)); }
+#sub floor {return int($_[0]); }
 
 sub format {
   my ($value,$fmt)=@_;
@@ -367,21 +368,83 @@ sub format {
 }
 
 sub map {
-  my $num = $#_/2;
-  my $i;
-  my @used;
-  my @permutation;
-  for ($i=0; $i < $num;) {
-    $rand = &random(1,$num,1);
-    if ( $used[$rand] == '0' ) {
-      $i++;
-      $used[$rand]='1';
-      $permutation[$i]=$rand;
+    my ($phrase,$dest,$source)=@_;
+    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] = $$dest[$idx[$ctr]];
+	    $ctr++;
+	}
+	return @output;
+    } else {
+	my $num = scalar(@$source);
+	my @idx = &math_random_permuted_index($num);
+	my $ctr = 0;
+	my $tot = $num;
+	$tot = $destct if $destct < $num;
+	if (ref($$dest[0])) {
+	    while ($ctr < $tot) {
+		${$$dest[$ctr]} = $$source[$idx[$ctr]];
+	        $ctr++;
+            }
+        } else {
+	    while ($ctr < $tot) {
+		$$dest[$ctr] = $$source[$idx[$ctr]];
+		$ctr++;
+	    }
+	}
+    }
+}
+
+sub rmap {
+    my ($phrase,$dest,$source)=@_;
+    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] = $$dest[$r_idx[$ctr]];
+	    $ctr++;
+	}
+	return @output;
+    } else {
+	my $num = scalar(@$source);
+	my @idx = &math_random_permuted_index($num);
+	my $ctr = 0;
+	my $tot = $num;
+	$tot = $destct if $destct < $num;
+	my @r_idx;
+	while ($ctr < $tot) {
+	    $r_idx[$idx[$ctr]] = $ctr;
+	    $ctr++;
+	}
+	$ctr = 0;
+	if (ref($$dest[0])) {
+	    while ($ctr < $tot) {
+		${$$dest[$ctr]} = $$source[$r_idx[$ctr]];
+	        $ctr++;
+            }
+        } else {
+	    while ($ctr < $tot) {
+		$$dest[$ctr] = $$source[$r_idx[$ctr]];
+		$ctr++;
+	    }
+	}
     }
-  }
-  for ( $i=1 ; $i<$num+1 ; $i++ ) {
-    ${$_[$permutation[$i]]}=$_[$i+$num]
-  }
 }
 
 sub capa_id { return }
@@ -458,7 +521,7 @@ sub array_moments {
   $output[0]=$N;
   if ($N <= 1) {
     $output[1]=$input[0];
-    $output[1] = "Input array not defined" if ($N == 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";