--- loncom/homework/default_homework.lcpm	2001/01/16 20:15:40	1.15
+++ loncom/homework/default_homework.lcpm	2001/06/14 21:29:14	1.28
@@ -1,19 +1,27 @@
-# file name (temp): default_homework 
+# file name (temp): default_homework
 # used by lonxml::xmlparse() as input variable $safeinit to Apache::run::run()
-# 
 #
+# Guy Albertelli
+#
+# 05/25/2001 H. K. Ng
+# 05/31/2001 H. K. Ng
+#
+#init some globals
 $RANDOMINIT=0;
+$pi=atan2(1,1)*4;
+$rad2deg=180.0/$pi;
+$deg2rad=$pi/180.0;
 
 sub caparesponse_check {
   my $answer='';  #done
   my $type='';    #done
   my $tol_type=''; # gets it's value from whether tol has a % or not done
   my $tol='';     #done
-  my $sig='';
-  my $sig_lbound='';
-  my $sig_ubound='';
+  my $sig='';     #done lowerbnd,upperbnd
+  my $sig_lbound=''; #done
+  my $sig_ubound=''; #done
   my $ans_fmt='';
-  my $units='';
+  my $units='';     #done
   my $calc='';
   my ($response,$expr)=@_;
   
@@ -69,7 +77,7 @@ sub caparesponse_check {
   elsif ($result =='12') { $result='WANTED_NUMERIC'; }
   else  {$result = "ERROR: Unknown Result:$result:$@:";}
 
-  return "$result:<br>Error $error:<br>Answer $answer:<br>Response $response:<br>$type|$tol|$tol_type|$sig:$sig_lbound:$sig_ubound|$units<br>";
+  return "$result:<br />Error $error:<br />Answer $answer:<br />Response $response:<br />$type|$tol|$tol_type|$sig:$sig_lbound:$sig_ubound|$units<br />";
 }
 
 sub caparesponse_check_list {
@@ -81,24 +89,29 @@ sub caparesponse_check_list {
   my (@list) = eval $answer;
   my (@responselist)=split /,/,$response;
   my $unit='';
-  $result.="Final response :$responselist['-1']:<br>";
+  $result.="Final response :$responselist['-1']:<br />";
   if ( $responselist['-1']=~ /(.*[^\s])\s+([^\s]+)/ ) {
     $responselist['-1']=$1;
     $unit=$2;
   }
-  $result.="Final response :$responselist['-1']:<br>";
+  $result.="Final response :$responselist['-1']:<br />";
   $unit=~s/\s//;
   my $i=0;
   my $awards='';
   for ($i=0; $i<@list;$i++) {
-    $aresult=&caparesponse_check($responselist[$i]." $unit",
-				 $expr.';my $answer='.$list[$i].';');
+    if ($unit eq '') {
+      $aresult=&caparesponse_check($responselist[$i],
+			     $expr.';my $answer='.$list[$i].';');
+    } else {
+      $aresult=&caparesponse_check($responselist[$i]." $unit",
+				   $expr.';my $answer='.$list[$i].';');
+    }
     my ($temp)=split /:/, $aresult;
     $awards.="$temp,";
     $result.=$aresult;
   }
   chop $awards;
-  return "$awards:<br>$result";
+  return "$awards:<br />$result";
 }
 
 sub tex {
@@ -109,18 +122,32 @@ sub tex {
   }
 }
 
+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") {
-      return @_[0];
-    } else {
       return @_[2];
+    } else {
+      return @_[0];
     }
   }
 }
 
+sub html {
+  if ( $external::target eq "web" ) {
+    return shift;
+  }
+}
+
 sub problem {
   return '1';
 }
@@ -137,20 +164,203 @@ sub random {
   return $result;
 }
 
+sub random_normal {
+  my ($item_cnt,$seed,$av,$std_dev) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_normal($item_cnt,$av,$std_dev);
+  return @retArray;
+}
+
+sub random_beta {
+  my ($item_cnt,$seed,$aa,$bb) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_beta($item_cnt,$aa,$bb);
+  return @retArray;
+}
+
+sub random_gamma {
+  my ($item_cnt,$seed,$a,$r) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_gamma($item_cnt,$a,$r);
+  return @retArray;
+}
+
+sub random_exponential {
+  my ($item_cnt,$seed,$av) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_exponential($item_cnt,$av);
+  return @retArray;
+}
+
+sub random_poisson {
+  my ($item_cnt,$seed,$mu) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_poisson($item_cnt,$mu);
+  return @retArray;
+}
+
+sub random_chi {
+  my ($item_cnt,$seed,$df) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_chi_square($item_cnt,$df);
+  return @retArray;
+}
+
+sub random_noncentral_chi {
+  my ($item_cnt,$seed,$df,$nonc) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_noncentral_chi_square($item_cnt,$df,$nonc);
+  return @retArray;
+}
+
+sub random_f {
+  my ($item_cnt,$seed,$dfn,$dfd) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_f($item_cnt,$dfn,$dfd);
+  return @retArray;
+}
+
+sub random_noncentral_f {
+  my ($item_cnt,$seed,$dfn,$dfd,$nonc) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_noncentral_f($item_cnt,$dfn,$dfd,$nonc);
+  return @retArray;
+}
+
+sub random_multivariate_normal {
+  my ($item_cnt,$seed,@mean) = @_;
+  return "Number of deviates must be greater than 0" if $item_cnt <= 0;
+  my (@covar,@retArray);
+  my $ind = 0;
+  while ($ind<$item_cnt) {
+     push @covar, pop (@mean);
+     $ind++;
+  }
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_multivariate_normal($item_cnt,@mean,@covar);
+  return @retArray;
+}
+
+sub random_multinomial {
+  my ($item_cnt,$seed,@p) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_multinomial($item_cnt,@p);
+  return @retArray;
+}
+
+sub random_permutation {
+  my ($seed,@inArray) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_permutation(@inArray);
+  return @retArray;
+}
+
+sub random_uniform {
+  my ($item_cnt,$seed,$low,$high) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_uniform($item_cnt,$low,$high);
+  return @retArray;
+}
+
+sub random_uniform_integer {
+  my ($item_cnt,$seed,$low,$high) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_uniform_integer($item_cnt,$low,$high);
+  return @retArray;
+}
+
+sub random_binomial {
+  my ($item_cnt,$seed,$nt,$p) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_binomial($item_cnt,$nt,$p);
+  return @retArray;
+}
+
+sub random_negative_binomial {
+  my ($item_cnt,$seed,$ne,$p) = @_;
+  my @retArray;
+  &random_set_seed_from_phrase($seed);
+  @retArray=&math_random_negative_binomial($item_cnt,$ne,$p);
+  return @retArray;
+}
+
+sub abs { abs(shift) }
+sub sin { sin(shift) }
+sub cos { cos(shift) }
+sub exp { exp(shift) }
+sub int { int(shift) }
+sub log { log(shift) }
+sub atan2 { atan2($_[0],$_[1]) }
+sub sqrt { sqrt(shift) }
+
 sub tan  { sin($_[0]) / cos($_[0]) }
-sub acos { atan2(sqrt(1 - $_[0] * $_[0]), $_[0] ); }
-sub asin { atan2($_[0], sqrt(1- $_[0] * $_[0]) );  }
+#sub atan { atan2($_[0], 1); }
+#sub acos { atan2(sqrt(1 - $_[0] * $_[0]), $_[0] ); }
+#sub asin { atan2($_[0], sqrt(1- $_[0] * $_[0]) );  }
 
-sub html {
-  if ( $external::target eq "web" ) {
-    return @_[0];
-  }
+sub log10 { log($_[0])/log(10); }
+
+sub factorial {
+    my $input = int(shift);
+    return "Error - unable to take factorial of an negative number ($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]-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)=@_;
@@ -158,30 +368,192 @@ 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++;
+	    }
+	}
+    }
+}
+
+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;
+#  return $dc[0].', '.$dc[1].' '.$dc[2].', '.$dc[4].' at '.$dc[3];
+}
+
+sub answer_date { 
+  my @dc = split(/\s+/,localtime(&EXT('resource.0.answerdate')));
+  return '' if ($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;
+#  return $dc[0].', '.$dc[1].' '.$dc[2].', '.$dc[4].' at '.$dc[3];
+}
+
+sub array_moments {
+  my @input=@_;
+  my (@output,$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;
   }
-  for ( $i=1 ; $i<$num+1 ; $i++ ) {
-    ${$_[$permutation[$i]]}=$_[$i+$num]
+  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);
+  $sdev=sqrt($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];
 }
-#$external::randomseed=time;
-#$a=2;
-#$b=2;
-#$c=2;
-#&map(1,\$a,\$b,\$c,3,4,5);
-#print $a."\n".$b."\n";
+
+