--- loncom/xml/lonplot.pm	2008/05/27 10:40:30	1.143
+++ loncom/xml/lonplot.pm	2012/07/03 11:29:57	1.156
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Dynamic plot
 #
-# $Id: lonplot.pm,v 1.143 2008/05/27 10:40:30 foxr Exp $
+# $Id: lonplot.pm,v 1.156 2012/07/03 11:29:57 foxr Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -26,6 +26,9 @@
 # http://www.lon-capa.org/
 #
 
+
+
+
 package Apache::lonplot;
 
 use strict;
@@ -57,6 +60,8 @@ BEGIN {
 }
 
 
+=pod
+
 ## 
 ## Description of data structures:
 ##
@@ -88,6 +93,8 @@ BEGIN {
 ##                                                               ##
 ###################################################################
 
+=cut
+
 my $max_str_len = 50;    # if a label, title, xlabel, or ylabel text
                          # is longer than this, it will be truncated.
 
@@ -169,14 +176,16 @@ my %gnuplot_defaults =
 	 test        => $color_test, 
 	 description => 'Background color of image (xffffff)',
 	 edit_type   => 'entry',
-	 size        => '10'
+	 size        => '10',
+         class       => 'colorchooser'
 	 },
      fgcolor      => {
 	 default     => 'x000000',
 	 test        => $color_test,
 	 description => 'Foreground color of image (x000000)',
 	 edit_type   => 'entry',
-	 size        => '10'
+	 size        => '10',
+         class       => 'colorchooser'
 	 },
      transparent  => {
 	 default     => 'off',
@@ -448,7 +457,7 @@ my %tic_defaults =
 	 },         
      );
 
-my @axis_edit_order = ('color','xmin','xmax','ymin','ymax','xformat', 'yformat');
+my @axis_edit_order = ('color','xmin','xmax','ymin','ymax','xformat', 'yformat', 'xzero', 'yzero');
 my %axis_defaults = 
     (
      color   => {
@@ -456,7 +465,8 @@ my %axis_defaults =
 	 test => $color_test,
 	 description => 'Color of grid lines (x000000)',
 	 edit_type   => 'entry',
-	 size        => '10'
+	 size        => '10',
+         class       => 'colorchooser'
 	 },
      xmin      => {
 	 default => '-10.0',
@@ -496,11 +506,26 @@ my %axis_defaults =
      yformat      => {
          default     => 'on',
          test        => sub {$_[0]=~/^(on|off|\d+(f|F|e|E))$/},
-         description => 'X-axis number formatting',
+         description => 'Y-axis number formatting',
          edit_type   => 'choice',
          choices     => ['on', 'off', '2e', '2f'],
          },
-
+     
+     xzero => {
+     	default => 'off',
+     	test	=> sub {$_[0]=~/^(off|line|thick-line|dotted)$/},
+     	description => 'Show x-zero (y=0) axis',
+     	edit_type  => 'choice',
+     	choices	=> ['off', 'line', 'thick-line', 'dotted'],
+     	},
+     
+     yzero => {
+     	default => 'off',
+     	test	=> sub {$_[0]=~/^(off|line|thick-line|dotted)$/},
+     	description => 'Show y-zero (x=0) axis',
+     	edit_type  => 'choice',
+     	choices	=> ['off', 'line', 'thick-line', 'dotted'],
+     	},
      );
 
 my @curve_edit_order = ('color','name','linestyle','linewidth','linetype','pointtype','pointsize','limit');
@@ -512,7 +537,8 @@ my %curve_defaults =
 	 test => $color_test,
 	 description => 'Color of curve (x000000)',
 	 edit_type   => 'entry',
-	 size        => '10'
+	 size        => '10',
+	 class       => 'colorchooser'
 	 },
      name      => {
 	 default => '',
@@ -598,7 +624,18 @@ sub start_gnuplot {
     } elsif ($target eq 'modified') {
 	my $constructtag=&Apache::edit::get_new_args
 	    ($token,$parstack,$safeeval,keys(%gnuplot_defaults));
+
 	if ($constructtag) {
+	    #
+	    # The color chooser does not prepent x to the color values
+	    # Do that here:
+	    #
+	    foreach my $attribute ('bgcolor', 'fgcolor') {
+		my $value = $token->[2]{$attribute};
+		if (defined $value && !($value =~ /^x/)) {
+		    $token->[2]{$attribute} = 'x' . $value;
+		}
+	    }
 	    $result = &Apache::edit::rebuild_tag($token);
 	}
     }
@@ -612,6 +649,8 @@ sub end_gnuplot {
 	('title','xlabel','ylabel','key','axis','label','curve'));
     my $result = '';
     my $randnumber;
+    my $tmpdir =LONCAPA::tempdir(); # Where temporary files live:
+
     # need to call rand everytime start_script would evaluate, as the
     # safe space rand number generator and the global rand generator 
     # are not separate
@@ -623,7 +662,6 @@ sub end_gnuplot {
 	&check_inputs(); # Make sure we have all the data we need
 	##
 	## Determine filename
-	my $tmpdir = '/home/httpd/perl/tmp/';
 	my $filename = $env{'user.name'}.'_'.$env{'user.domain'}.
 	    '_'.time.'_'.$$.$randnumber.'_plot';
 	## Write the plot description to the file
@@ -644,7 +682,7 @@ ENDIMAGE
 	    #might be inside the safe space, register the URL for later
 	    &Apache::lonxml::register_ssi("/cgi-bin/plot.gif?file=$filename.data&output=eps");
 	    $result  = "%DYNAMICIMAGE:$Apache::lonplot::plot{'width'}:$Apache::lonplot::plot{'height'}:$Apache::lonplot::plot{'texwidth'}\n";
-	    $result .= '\graphicspath{{/home/httpd/perl/tmp/}}'."\n";
+	    $result .= '\graphicspath{{'.$tmpdir.'}}'."\n";
 	    $result .= '\includegraphics[width='.$Apache::lonplot::plot{'texwidth'}.' mm]{'.&unescape($filename).'.eps}';
 	}
     } elsif ($target eq 'edit') {
@@ -757,6 +795,7 @@ sub get_font {
 	$selected_font = $font_properties{$Apache::lonplot::plot{'fontface'}};
     }
     if ($target eq 'tex' && defined($Apache::lonplot::plot{'texfont'})) {
+#	$selected_font = $font_properties{'classic'};
 	$size = $Apache::lonplot::plot{'texfont'};
     }
     return ($size, $selected_font);
@@ -1037,30 +1076,30 @@ my %lookup =
       '(ensp|#8194)'   => {'tex' => ' ',              'web' => "\x{2002}"}, # en space.
       '(emsp|#8195)'   => {'tex' => ' ',              'web' => "\x{2003}"}, # em space.
       '(thinsp|#8201)' => {'tex' => ' ',              'web' => "\x{2009}"}, # thin space.
-      '(zwnj|#8204)'   => {'tex' => '',               'web' => "\x{200c}"}, # Zero width non joiner.
-      '(zwj|#8205)'    => {'tex' => '',               'web' => "\x{200d}"}, # Zero width joiner.
-      '(lrm|#8206)'    => {'tex' => '',               'web' => "\x{200e}"}, # Left to right mark
-      '(rlm|#8207)'    => {'tex' => '',               'web' => "\x{200f}"}, # right to left mark.
+      '(zwnj|#8204)'   => {'tex' => ' ',               'web' => "\x{200c}"}, # Zero width non joiner.
+      '(zwj|#8205)'    => {'tex' => ' ',               'web' => "\x{200d}"}, # Zero width joiner.
+      '(lrm|#8206)'    => {'tex' => ' ',               'web' => "\x{200e}"}, # Left to right mark
+      '(rlm|#8207)'    => {'tex' => ' ',               'web' => "\x{200f}"}, # right to left mark.
       '(ndash|#8211)'  => {'tex' => '{/Text \55}',    'web' => "\x{2013}"}, # en dash.
       '(mdash|#8212)'  => {'tex' => '{/Symbol \55}',  'web' => "\x{2014}"}, # em dash.
       '(lsquo|#8216)'  => {'tex' => '{/Text \140}',   'web' => "\x{2018}"}, # Left single quote.
-      '(rsquo|#8217)'  => {'tex' => '{/Symbol \242}', 'web' => "\x{2019}"}, # Right single quote.
-      '(sbquo|#8218)'  => {'tex' => ',',              'web' => "\x{201a}"}, # Single low-9 quote.
-      '(ldquo|#8220)'  => {'tex' => '{/Text \252}',   'web' => "\x{201c}"}, # Left double quote.
-      '(rdquo|#8221)'  => {'tex' => '{/Text \272}',   'web' => "\x{201d}"}, # Right double quote.
-      '(bdquo|#8222)'  => {'tex' => '{/Text \271}',   'web' => "\x{201e}"}, # Double low-9 quote.
-      '(dagger|#8224)' => {'tex' => '{/Text \262}',   'web' => "\x{2020}"}, # Is this a dagger I see before me now?
-      '(Dagger|#8225)' => {'tex' => '{/Text \263}',   'web' => "\x{2021}"}, # it's handle pointing towards my heart?
+      '(rsquo|#8217)'  => {'tex' => '\47',            'web' => "\x{2019}"}, # Right single quote.
+      '(sbquo|#8218)'  => {'tex' => '\54',             'web' => "\x{201a}"}, # Single low-9 quote.
+      '(ldquo|#8220)'  => {'tex' => '\42',   'web' => "\x{201c}"}, # Left double quote.
+      '(rdquo|#8221)'  => {'tex' => '\42',   'web' => "\x{201d}"}, # Right double quote.
+      '(bdquo|#8222)'  => {'tex' => ',',              'web' => "\x{201e}"}, # Double low-9 quote.
+      '(dagger|#8224)' => {'tex' => '+',   'web' => "\x{2020}"}, # Is this a dagger I see before me now?
+      '(Dagger|#8225)' => {'tex' => '\261',   'web' => "\x{2021}"}, # it's handle pointing towards my heart?
       '(bull|#8226)'   => {'tex' => '\267',           'web' => "\x{2022}"}, # Bullet.
-      '(hellep|#8230)' => {'tex' => '{/Text \274}',   'web' => "\x{2026}"}, # Ellipses.
-      '(permil|#8240)' => {'tex' => '{/Text \275}',   'web' => "\x{2031}"}, # Per mille.
+      '(hellep|#8230)' => {'tex' => '{/Symbol \274}',   'web' => "\x{2026}"}, # Ellipses.
+      '(permil|#8240)' => {'tex' => '%_o',            'web' => "\x{2031}"}, # Per mille.
       '(prime|#8242)'  => {'tex' => '\264',           'web' => "\x{2032}"}, # Prime.
       '(Prime|#8243)'  => {'tex' => '{/Symbol \262}', 'web' => "\x{2033}"}, # double prime.
-      '(lsaquo|#8249)' => {'tex' => '{/Text \254}',   'web' => "\x{2039}"}, # < quote.
-      '(rsaquo|#8250)' => {'tex' => '{/Text \255}',   'web' => "\x{2040}"}, # > quote.
+      '(lsaquo|#8249)' => {'tex' => '<',              'web' => "\x{2039}"}, # < quote.
+      '(rsaquo|#8250)' => {'tex' => '\74',              'web' => "\x{203a}"}, # > quote.
       '(oline|#8254)'  => {'tex' => '{/Symbol \140}', 'web' => "\x{203e}"}, # Overline.
       '(frasl|#8260)'  => {'tex' => '/',              'web' => "\x{2044}"}, # Fraction slash.
-      '(euro|#8364)'   => {'tex' => '{/Symbol \240}', 'web' => "\x{20a0}"}, # Euro currency.
+      '(euro|#8364)'   => {'tex' => '{/Symbol \240}', 'web' => "\x{20ac}"}, # Euro currency.
       
       # Letter like symbols.
 
@@ -1091,10 +1130,11 @@ my %lookup =
       '(empty|#8709)'   => {'tex' => '{/Symbol \306}',  'web' => "\x{2205}"}, # Null set.
       '(nabla|#8711)'   => {'tex' => '{/Symbol \321}',  'web' => "\x{2207}"}, # Gradient e.g.
       '(isin|#8712)'    => {'tex' => '{/Symbol \316}',  'web' => "\x{2208}"}, # Element of the set.
+      '(notin|#8713)'   => {'tex' => '{/Symbol \317}',  'web' => "\x{2209}"}, # Not an element of
       '(ni|#8715)'      => {'tex' => '{/Symbol \47}',   'web' => "\x{220b}"}, # Contains as a member
       '(prod|#8719)'    => {'tex' => '{/Symbol \325}',  'web' => "\x{220f}"}, # Product 
       '(sum|#8721)'     => {'tex' => '{/Symbol \345}',  'web' => "\x{2211}"}, # Sum of.
-      '(minus|#8722)'   => {'tex' => '-',               'web' => "\x{2212}"}, # - sign.
+      '(minus|#8722)'   => {'tex' => '{/Symbol \55}',   'web' => "\x{2212}"}, # - sign.
       '(lowast|#8727)'  => {'tex' => '*',               'web' => "\x{2217}"}, # * 
       '(radic|#8730)'   => {'tex' => '{/Symbol \326}',  'web' => "\x{221a}"}, # Square root. 
       '(prop|#8733)'    => {'tex' => '{/Symbol \265}',  'web' => "\x{221d}"}, # Proportional to.
@@ -1105,10 +1145,15 @@ my %lookup =
       '(cap|#8745)'     => {'tex' => '{/Symbol \307}',  'web' => "\x{2229}"}, # Set intersection.
       '(cup|#8746)'     => {'tex' => '{/Symbol \310}',  'web' => "\x{222a}"}, # Set union.
       '(int|8747)'      => {'tex' => '{/Symbol \362}',  'web' => "\x{222b}"}, # Integral.
-      '(there4|#8756)'  => {'tex' => '{/Symbol \134}',  'web' => "\x{2234}"}, # Therefore triple dots.
-      '(sim|#8764)'     => {'tex' => '~',               'web' => "\x{223c}"}, # Simlar to.
-      '(cong|#8773)'    => {'tex' => '{/Symbol \100}',  'web' => "\x{2245}"}, # Congruent to/with.
-      '(asymp|#8776)'   => {'tex' => '{/Symbol \278}',  'web' => "\x{2248}"}, # Asymptotic to.
+
+      # Some gnuplot guru will have to explain to me why the next three
+      # require the extra slashes... else they print very funkily.
+
+      '(there4|#8756)'  => {'tex' => '{/Symbol \\\134}',  'web' => "\x{2234}"}, # Therefore triple dots.
+      '(sim|#8764)'     => {'tex' => '\\\176',               'web' => "\x{223c}"}, # Simlar to.
+      '(cong|#8773)'    => {'tex' => '{/Symbol \\\100}','web' => "\x{2245}"}, # Congruent to/with.
+
+      '(asymp|#8776)'   => {'tex' => '{/Symbol \273}',  'web' => "\x{2248}"}, # Asymptotic to.
       '(ne|#8800)'      => {'tex' => '{/Symbol \271}',  'web' => "\x{2260}"}, # not equal to.
       '(equiv|#8801)'   => {'tex' => '{/Symbol \272}',  'web' => "\x{2261}"}, # Equivalent to.
       '(le|8804)'       => {'tex' => '{/Symbol \243}',  'web' => "\x{2264}"}, # Less than or equal to.
@@ -1129,8 +1174,12 @@ my %lookup =
       '(rceil|8969)'    => {'tex' => '{/Symbol \371}',  'web' => "\x{2309}"}, # Right ceiling.
       '(lfloor|8970)'   => {'tex' => '{/Symbol \353}',  'web' => "\x{230a}"}, # Left floor.
       '(rfloor|8971)'   => {'tex' => '{/Symbol \373}',  'web' => "\x{230b}"}, # Right floor.
-      '(lang|9001)'     => {'tex' => '{/Symbol \341}',  'web' => "\x{2329}"}, # Left angle bracket.
-      '(rang|9002)'     => {'tex' => '{/Symbol \361}',  'web' => "\x{232a}"}, # Right angle bracket.
+
+      # The gnuplot png font evidently does not have the big angle brackets at
+      # positions 0x2329, 0x232a so use ordinary brackets.
+
+      '(lang|9001)'     => {'tex' => '{/Symbol \341}',  'web' => '<'}, # Left angle bracket.
+      '(rang|9002)'     => {'tex' => '{/Symbol \361}',  'web' => '>'}, # Right angle bracket.
 
       # Gemoetric shapes.
 
@@ -1317,6 +1366,13 @@ sub start_curve {
 	my $constructtag=&Apache::edit::get_new_args
 	    ($token,$parstack,$safeeval,keys(%curve_defaults));
 	if ($constructtag) {
+	    #
+	    # Fix up the color attribute as jcolor does not prepend an x
+	    #
+	    my $value = $token->[2]{'color'};
+	    if (defined $value && !($value =~ /^x/)) {
+		$token->[2]{'color'} = 'x' . $value;
+	    }
 	    $result = &Apache::edit::rebuild_tag($token);
 	}
     }
@@ -1351,6 +1407,7 @@ sub start_function {
         my $function = &Apache::lonxml::get_all_text("/function",$parser,
 						     $style);
 	$function = &Apache::run::evaluate($function,$safeeval,$$parstack[-1]);
+        $function=~s/\^/\*\*/gs;
 	$curves[-1]->{'function'} = $function; 
     } elsif ($target eq 'edit') {
 	$result .= &Apache::edit::tag_start($target,$token,'Gnuplot compatible curve function');
@@ -1421,7 +1478,7 @@ sub start_data {
 	}
 	# complain if the number of data points is not the same as
 	# in previous sets of data.
-	if (($curves[-1]->{'data'}) && ($#data != $#{@{$curves[-1]->{'data'}->[0]}})){
+	if (($curves[-1]->{'data'}) && ($#data != $#{$curves[-1]->{'data'}->[0]})){
 	    &Apache::lonxml::warning
 		('Number of data points is not consistent with previous '.
 		 'number of data points');
@@ -1462,7 +1519,17 @@ sub start_axis {
     } elsif ($target eq 'modified') {
 	my $constructtag=&Apache::edit::get_new_args
 	    ($token,$parstack,$safeeval,keys(%axis_defaults));
+
 	if ($constructtag) {
+	    #
+	    #  Fix up the color attribute since jchooser does not
+	    #  prepend an x to the color:
+	    #
+	    my $value = $token->[2]{'color'};
+	    if (defined $value && !($value =~ /^x/)) {
+		$token->[2]{'color'} = 'x' . $value;
+	    }
+
 	    $result = &Apache::edit::rebuild_tag($token);
 	}
     }
@@ -1555,6 +1622,7 @@ sub write_gnuplot_file {
 		       $curve->{'color'}       : 
 		       $Apache::lonplot::plot{'fgcolor'}        );
     }
+    
     # set term
     if ($target eq 'web') {
 	$gnuplot_input .= 'set terminal png enhanced nocrop ';
@@ -1567,7 +1635,7 @@ sub write_gnuplot_file {
 	# set output
 	$gnuplot_input .= "set output\n";
     } elsif ($target eq 'tex') {
-	$gnuplot_input .= "set term postscript eps enhanced $Apache::lonplot::plot{'plotcolor'} solid ";
+	$gnuplot_input .= "set term postscript eps enhanced $Apache::lonplot::plot{'plotcolor'} dash ";
 	if (!$font_properties->{'tex_no_file'}) {
 	    $gnuplot_input .=
 		'fontfile "'.$Apache::lonnet::perlvar{'lonFontsDir'}.
@@ -1575,7 +1643,7 @@ sub write_gnuplot_file {
 	}
 	$gnuplot_input .= ' "'.$font_properties->{'printname'}.'" ';
 	$gnuplot_input .= $fontsize;
-	$gnuplot_input .= "\nset output \"/home/httpd/perl/tmp/".
+	$gnuplot_input .= "\nset output \"".$tmpdir.
 	    &unescape($filename).".eps\"\n";
 	$gnuplot_input .= "set encoding iso_8859_1\n"; # Get access to extended font.
 
@@ -1665,20 +1733,36 @@ sub write_gnuplot_file {
 	$gnuplot_input .= ( $xtics{'mirror'} eq 'on'?"mirror ":"nomirror ");
 	$gnuplot_input .= "$xtics{'start'}, ";
 	$gnuplot_input .= "$xtics{'increment'}, ";
-	$gnuplot_input .= "$xtics{'end'}\n";
+	$gnuplot_input .= "$xtics{'end'} ";
+	if ($target eq 'tex') {
+	    $gnuplot_input .= 'font "Helvetica,22"';     # Needed in iso 8859-1 enc.
+	}
+	$gnuplot_input .= "\n";
         if ($xtics{'minorfreq'} != 0) {
             $gnuplot_input .= "set mxtics ".$xtics{'minorfreq'}."\n";
         } 
+    } else {
+	if ($target eq 'tex') {
+	    $gnuplot_input .= 'set xtics font "Helvetica,22"'."\n"; # needed in iso 8859-1 enc
+	}
     }
     if (%ytics) {    
 	$gnuplot_input .= "set ytics $ytics{'location'} ";
 	$gnuplot_input .= ( $ytics{'mirror'} eq 'on'?"mirror ":"nomirror ");
 	$gnuplot_input .= "$ytics{'start'}, ";
 	$gnuplot_input .= "$ytics{'increment'}, ";
-        $gnuplot_input .= "$ytics{'end'}\n";
+        $gnuplot_input .= "$ytics{'end'} ";
+        if ($target eq 'tex') {
+            $gnuplot_input .= 'font "Helvetica,22"'; # Needed in iso-8859-1 encoding.
+        }
+        $gnuplot_input .= "\n";
         if ($ytics{'minorfreq'} != 0) {
             $gnuplot_input .= "set mytics ".$ytics{'minorfreq'}."\n";
         } 
+    } else {
+	if ($target eq 'tex') {
+	    $gnuplot_input .= 'set ytics font "Helvetica,22"'."\n"; # Needed for iso 8859-1 enc.
+	}
     }
     # axis
     if (%axis) {
@@ -1700,6 +1784,26 @@ sub write_gnuplot_file {
         }
 	$gnuplot_input .= "set xrange \[$axis{'xmin'}:$axis{'xmax'}\]\n";
 	$gnuplot_input .= "set yrange \[$axis{'ymin'}:$axis{'ymax'}\]\n";
+		if ($axis{'xzero'} ne 'off') {
+			$gnuplot_input .= "set xzeroaxis ";
+			if ($axis{'xzero'} eq 'line' || $axis{'xzero'} eq 'thick-line') {
+				$gnuplot_input .= "lt -1 ";
+				if ($axis{'xzero'} eq 'thick-line') {
+					$gnuplot_input .= "lw 3 ";
+				}
+			}
+			$gnuplot_input .= "\n";
+		}
+		if ($axis{'yzero'} ne 'off') {
+			$gnuplot_input .= "set yzeroaxis ";
+			if ($axis{'yzero'} eq 'line' || $axis{'yzero'} eq 'thick-line') {
+				$gnuplot_input .= "lt -1 ";
+				if ($axis{'yzero'} eq 'thick-line') {
+					$gnuplot_input .= "lw 3 ";
+				}
+			}
+			$gnuplot_input .= "\n";
+		}
     }
     # Key
     if (%key) {
@@ -1731,40 +1835,31 @@ sub write_gnuplot_file {
         $gnuplot_input .="\n";
     }
     # curves
-    $gnuplot_input .= 'plot ';
+    #
+    # Each curve will have its very own linestyle.
+    # (This should work just fine in web rendition I think).
+    #  The line_xxx variables will hold the elements of the line style.
+    #  type (solid/dashed), color, width
+    #
+    my $linestyle_index = 50;
+    my $line_type    = '';     
+    my $line_color   = '';
+    my $line_width   = '';
+
+    my $plot_command;
+    my $plot_type;
+
     for (my $i = 0;$i<=$#curves;$i++) {
 	$curve = $curves[$i];
-	$gnuplot_input.= ', ' if ($i > 0);
+	$plot_command.= ', ' if ($i > 0);
 	if ($target eq 'tex') {
 	    $curve->{'linewidth'} *= 2;
 	}
 	if (exists($curve->{'function'})) {
-	    $gnuplot_input.= 
+	    $plot_type    = 
 		$curve->{'function'}.' title "'.
 		$curve->{'name'}.'" with '.
                 $curve->{'linestyle'};
-
-            if (($curve->{'linestyle'} eq 'points')      ||
-                ($curve->{'linestyle'} eq 'linespoints') ||
-                ($curve->{'linestyle'} eq 'errorbars')   ||
-                ($curve->{'linestyle'} eq 'xerrorbars')  ||
-                ($curve->{'linestyle'} eq 'yerrorbars')  ||
-                ($curve->{'linestyle'} eq 'xyerrorbars')) {
-                $gnuplot_input.=' pointtype '.$curve->{'pointtype'};
-                $gnuplot_input.=' pointsize '.$curve->{'pointsize'};
-            } elsif ($curve->{'linestyle'} eq 'filledcurves') { 
-                $gnuplot_input.= ' '.$curve->{'limit'};
-            } elsif ($curve->{'linetype'} ne '' &&
-                     $curve->{'linestyle'} eq 'lines') {
-                $gnuplot_input.= ' linetype ';
-                $gnuplot_input.= $linetypes{$curve->{'linetype'}};
-                $gnuplot_input.= ' linecolor rgb "';
-                # convert color from xaaaaaa to #aaaaaa
-                $curve->{'color'} =~ s/^x/#/;
-                $gnuplot_input.= $curve->{'color'}.'"';
-            }
-            $gnuplot_input.= ' linewidth '.$curve->{'linewidth'};
-
 	} elsif (exists($curve->{'data'})) {
 	    # Store data values in $datatext
 	    my $datatext = '';
@@ -1785,30 +1880,31 @@ sub write_gnuplot_file {
 	    print $fh $datatext;
 	    close($fh);
 	    #   generate gnuplot text
-	    $gnuplot_input.= '"'.$datafilename.'" title "'.
+	    $plot_type = '"'.$datafilename.'" title "'.
 		$curve->{'name'}.'" with '.
 		$curve->{'linestyle'};
-            if (($curve->{'linestyle'} eq 'points')      ||
-                ($curve->{'linestyle'} eq 'linespoints') ||
-                ($curve->{'linestyle'} eq 'errorbars')   ||
-                ($curve->{'linestyle'} eq 'xerrorbars')  ||
-                ($curve->{'linestyle'} eq 'yerrorbars')  ||
-                ($curve->{'linestyle'} eq 'xyerrorbars')) {
-                $gnuplot_input.=' pointtype '.$curve->{'pointtype'};
-                $gnuplot_input.=' pointsize '.$curve->{'pointsize'};
-            } elsif ($curve->{'linestyle'} eq 'filledcurves') { 
-                $gnuplot_input.= ' '.$curve->{'limit'};
-            } elsif ($curve->{'linetype'} ne '' &&
-                     $curve->{'linestyle'} eq 'lines') {
-                $gnuplot_input.= ' linetype ';
-                $gnuplot_input.= $linetypes{$curve->{'linetype'}};
-                $gnuplot_input.= ' linecolor rgb "';
-                # convert color from xaaaaaa to #aaaaaa
-                $curve->{'color'} =~ s/^x/#/;
-                $gnuplot_input.= $curve->{'color'}.'"';
-            }
-                $gnuplot_input.= ' linewidth '.$curve->{'linewidth'}; 
 	}
+	if (($curve->{'linestyle'} eq 'points')      ||
+	    ($curve->{'linestyle'} eq 'linespoints') ||
+	    ($curve->{'linestyle'} eq 'errorbars')   ||
+	    ($curve->{'linestyle'} eq 'xerrorbars')  ||
+	    ($curve->{'linestyle'} eq 'yerrorbars')  ||
+	    ($curve->{'linestyle'} eq 'xyerrorbars')) {
+	    $plot_command.=' pointtype '.$curve->{'pointtype'};
+	    $plot_command.=' pointsize '.$curve->{'pointsize'};
+	} elsif ($curve->{'linestyle'} eq 'filledcurves') { 
+	    $plot_command.= ' '.$curve->{'limit'};
+	} elsif ($curve->{'linetype'} ne '' &&
+		 $curve->{'linestyle'} eq 'lines') {
+	    $plot_command.= ' linetype ';
+	    $plot_command.= $linetypes{$curve->{'linetype'}};
+	    $plot_command.= ' linecolor rgb "';
+	    # convert color from xaaaaaa to #aaaaaa
+	    $curve->{'color'} =~ s/^x/#/;
+	    $plot_command.= $curve->{'color'}.'"';
+	}
+	$plot_command.= ' linewidth '.$curve->{'linewidth'};
+	$gnuplot_input .= 'plot ' . $plot_type . ' ' . $plot_command . "\n";
     }
     # Write the output to a file.
     open (my $fh,">$tmpdir$filename.data");
@@ -1859,7 +1955,8 @@ sub edit_attributes {
 	if ($defaults->{$attr}->{'edit_type'} eq 'entry') {
 	    $result .= &Apache::edit::text_arg
 		($description,$attr,$token,
-		 $defaults->{$attr}->{'size'});
+		 $defaults->{$attr}->{'size'},
+		$defaults->{$attr}->{'class'});
 	} elsif ($defaults->{$attr}->{'edit_type'} eq 'choice') {
 	    $result .= &Apache::edit::select_or_text_arg
 		($description,$attr,$defaults->{$attr}->{'choices'},$token);
@@ -1988,3 +2085,118 @@ sub insert_data {
 __END__
 
 
+=head1 NAME
+
+Apache::lonplot.pm
+
+=head1 SYNOPSIS
+
+XML-based plotter of graphs
+
+This is part of the LearningOnline Network with CAPA project
+described at http://www.lon-capa.org.
+
+
+=head1 SUBROUTINES (parsing and edit rendering)
+
+=over
+
+=item start_gnuplot()
+
+=item end_gnuplot()
+
+=item start_xtics()
+
+=item end_xtics()
+
+=item start_ytics()
+
+=item end_ytics()
+
+=item get_font()
+
+=item start_key()
+
+=item end_key()
+
+=item parse_label()
+
+=item replace_entities()
+
+=item start_title()
+
+=item end_title()
+
+=item start_xlabel()
+
+=item end_xlabel()
+
+=item start_ylabel()
+
+=item end_label()
+
+=item start_curve()
+
+=item end_curve()
+
+=item start_function()
+
+=item end_function()
+
+=item start_data()
+
+=item end_data()
+
+=item start_axis()
+
+=item end_axis
+
+=back
+
+=head1 SUBROUTINES (Utility)
+
+=over
+
+=item set_defaults()
+
+=item get_attributes()
+
+=item write_gnuplot_file()
+
+=item check_inputs()
+
+=item edit_attributes()
+
+=back
+
+=head1 SUBROUTINES (Insertion functions for editing plots)
+
+=over
+
+=item insert_gnuplot()
+
+=item insert_tics()
+
+=item insert_xtics()
+
+=item insert_key()
+
+=item insert_axis()
+
+=item insert_title()
+
+=item insert_xlabel()
+
+=item insert_ylabel()
+
+=item insert_label()
+
+=item insert_curve()
+
+=item insert_function()
+
+=item insert_data()
+
+=back
+
+=cut