--- loncom/homework/default_homework.lcpm	2001/05/28 21:47:48	1.21
+++ loncom/homework/default_homework.lcpm	2001/05/31 22:36:18	1.25
@@ -1,16 +1,16 @@
-# file name (temp): default_homework 
+# file name (temp): default_homework
 # used by lonxml::xmlparse() as input variable $safeinit to Apache::run::run()
-# 
-#
-#init some globals
-#use Math::Trig;
 #
 # Guy Albertelli
 #
 # 05/25/2001 H. K. Ng
+# 05/31/2001 H. K. Ng
 #
+#init some globals
 $RANDOMINIT=0;
-#$pi=atan2(1,1)*4;
+$pi=atan2(1,1)*4;
+$rad2deg=180.0/$pi;
+$deg2rad=$pi/180.0;
 
 sub caparesponse_check {
   my $answer='';  #done
@@ -122,6 +122,14 @@ sub tex {
   }
 }
 
+sub var_in_tex {
+  if ( $external::target eq "tex" ) {
+    return @_[0];
+  } else {
+    return "";
+  }
+}
+
 sub web {
   if ( $external::target eq "tex" ) {
     return @_[1];
@@ -134,6 +142,12 @@ sub web {
   }
 }
 
+sub html {
+  if ( $external::target eq "web" ) {
+    return @_[0];
+  }
+}
+
 sub problem {
   return '1';
 }
@@ -150,11 +164,22 @@ sub random {
   return $result;
 }
 
+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 atan { atan2($_[0], 1); }
 #sub acos { atan2(sqrt(1 - $_[0] * $_[0]), $_[0] ); }
 #sub asin { atan2($_[0], sqrt(1- $_[0] * $_[0]) );  }
+
 sub log10 { log($_[0])/log(10); }
+
 sub factorial {
     my $input = int(shift);
     return "Error - unable to take factorial of an negative number ($input)" if $input < 0;
@@ -181,12 +206,6 @@ sub max {
     return pop @sorted;
 }
 
-sub html {
-  if ( $external::target eq "web" ) {
-    return @_[0];
-  }
-}
-
 sub roundto {
     my ($input,$n) = @_;
     return sprintf('%.'.$n.'f',$input);
@@ -230,13 +249,113 @@ sub map {
   }
 }
 
+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/-/;
+  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;
+  }
+  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";
+
+