--- loncom/xml/lonplot.pm	2001/12/17 21:43:12	1.1
+++ loncom/xml/lonplot.pm	2003/10/24 17:35:32	1.92
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Dynamic plot
 #
-# $Id: lonplot.pm,v 1.1 2001/12/17 21:43:12 matthew Exp $
+# $Id: lonplot.pm,v 1.92 2003/10/24 17:35:32 matthew Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -25,186 +25,764 @@
 #
 # http://www.lon-capa.org/
 #
-# 2/21 Guy
+# 12/15/01 Matthew
+# 12/17 12/18 12/19 12/20 12/21 12/27 12/28 12/30 12/31 Matthew
+# 01/01/02 Matthew
+# 01/02 01/03 01/04 01/07 01/08 01/09 Matthew
+# 01/21 02/05 02/06 2/28Matthew
+
 package Apache::lonplot;
+
 use strict;
+use warnings FATAL=>'all';
+no warnings 'uninitialized';
+use Apache::File;
 use Apache::response;
+use Apache::lonxml;
+use Apache::edit;
 
-sub BEGIN {
-  &Apache::lonxml::register('Apache::lonplot',('plot'));
+BEGIN {
+  &Apache::lonxml::register('Apache::lonplot',('gnuplot'));
 }
 
-
+## 
+## Description of data structures:
+##
+##  %plot       %key    %axis
+## --------------------------
+##  height      title   color
+##  width       box     xmin
+##  bgcolor     pos     xmax
+##  fgcolor             ymin
+##  transparent         ymax
+##  grid
+##  border
+##  font
+##  align
+##
+##  @labels: $labels[$i] = \%label
+##           %label: text, xpos, ypos, justify
+##
+##  @curves: $curves[$i] = \%curve
+##           %curve: name, linestyle, ( function | data )
 ##
-## Tests used in checking the validitity of input
+##  $curves[$i]->{'data'} = [ [x1,x2,x3,x4],
+##                            [y1,y2,y3,y4] ]
 ##
-my $int_test       = sub {$_[0]=~/^\d+$/};
-my $real_test      = sub {$_[0]=~/^[+-]?\d*\.?\d*$/};
-my $color_test     = sub {$_[0]=~/^x[\da-f]{6}$/};
+
+###################################################################
+##                                                               ##
+##        Tests used in checking the validitity of input         ##
+##                                                               ##
+###################################################################
+
+my $max_str_len = 50;    # if a label, title, xlabel, or ylabel text
+                         # is longer than this, it will be truncated.
+
+my %linestyles = 
+    (
+     lines          => 2,     # Maybe this will be used in the future
+     linespoints    => 2,     # to check on whether or not they have 
+     dots	    => 2,     # supplied enough <data></data> fields
+     points         => 2,     # to use the given line style.  But for
+     steps	    => 2,     # now there are more important things 
+     fsteps	    => 2,     # for me to deal with.
+     histeps        => 2,
+     errorbars	    => 3,
+     xerrorbars	    => [3,4],
+     yerrorbars	    => [3,4],
+     xyerrorbars    => [4,6],
+     boxes          => 3,
+     vector	    => 4
+    );		    
+
+my $int_test       = sub {$_[0]=~s/\s+//g;$_[0]=~/^\d+$/};
+my $real_test      = 
+    sub {$_[0]=~s/\s+//g;$_[0]=~/^[+-]?\d*\.?\d*([eE][+-]\d+)?$/};
+my $pos_real_test  =
+    sub {$_[0]=~s/\s+//g;$_[0]=~/^[+]?\d*\.?\d*([eE][+-]\d+)?$/};
+my $color_test     = sub {$_[0]=~s/\s+//g;$_[0]=~/^x[\da-fA-F]{6}$/};
 my $onoff_test     = sub {$_[0]=~/^(on|off)$/};
-my $key_pos_test   = sub {$_[0]=~/^(top|bottom|right|left|outside|below)+$/};
+my $key_pos_test   = sub {$_[0]=~/^(top|bottom|right|left|outside|below| )+$/};
 my $sml_test       = sub {$_[0]=~/^(small|medium|large)$/};
-my $linestyle_test = sub {$_[0]=~/^(lines|linespoints|dots|points|steps)$/};
+my $linestyle_test = sub {exists($linestyles{$_[0]})};
+my $words_test     = sub {$_[0]=~s/\s+/ /g;$_[0]=~/^([\w~!\@\#\$\%^&\*\(\)-=_\+\[\]\{\}:\;\'<>,\.\/\?\\]+ ?)+$/};
 
-##
-## Default values for attributes of elements
-##
-my %plot_defaults = 
+###################################################################
+##                                                               ##
+##                      Attribute metadata                       ##
+##                                                               ##
+###################################################################
+my @gnuplot_edit_order = 
+    qw/alttag bgcolor fgcolor height width font transparent grid samples 
+    border align texwidth texfont plottype/;
+
+my $gnuplot_help_text = <<"ENDPLOTHELP";
+<p>
+The <b>gnuplot</b> tag allows an author to design a plot which can
+be created on the fly.  This is intended for use in homework problems
+where each student needs to see a distinct plot.  It can be used in
+conjunction with a <b>script</b> tag to generate random plots.
+</p><p>
+A <b>gnuplot</b> tag can contain the following sub-tags:
+</p>
+<dl>
+<dt> Plot Label
+    <dd> Allows you to place text at a given (x,y) coordinate on the plot.
+<dt> Plot Title
+    <dd> The title of the plot
+<dt> Plot Xlabel
+    <dd> The label on the horizontal axis of the plot
+<dt> Plot Ylabel
+    <dd> The label on the vertical axis of the plot
+<dt> Plot Axes
+    <dd> allows specification of the x and y ranges displayed in the plot
+<dt> Plot Key
+    <dd> Lists the functions displayed in the plot.
+<dt> Plot Curve
+    <dd> Sets the data used in the plot.
+<dt> Plot Tics
+    <dd> Allows specification of the x and y coordinate 'tics' on the axes.
+This is mostly used to adjust the grid lines when a grid is displayed.
+</dl>
+If you are having trouble with your plot, please read the help
+available on Plot Curve.
+ENDPLOTHELP
+
+my %gnuplot_defaults = 
     (
-     height       => {default => 200,       test => $int_test  },
-     width        => {default => 200,       test => $int_test  },
-     bgcolor      => {default => "xffffff", test => $color_test},
-     fgcolor      => {default => "x000000", test => $color_test},
-     transparent  => {default => "off",     test => $onoff_test},
-     grid         => {default => "off",     test => $onoff_test},
-     border       => {default => "on" ,     test => $onoff_test},
-     font         => {default => "medium",  test => $sml_test  }
+     alttag       => {
+	 default     => 'dynamically generated plot',
+	 test        => $words_test,
+	 description => 'brief description of the plot',
+      	 edit_type   => 'entry',
+	 size        => '40'
+	 },
+     height       => {
+	 default     => 300,
+	 test        => $int_test,
+	 description => 'height of image (pixels)',
+      	 edit_type   => 'entry',
+	 size        => '10'
+	 },
+     width        => {
+	 default     => 400,
+	 test        => $int_test,
+	 description => 'width of image (pixels)',
+	 edit_type   => 'entry',
+	 size        => '10'
+	 },
+     bgcolor      => {
+	 default     => 'xffffff',
+	 test        => $color_test, 
+	 description => 'background color of image (xffffff)',
+	 edit_type   => 'entry',
+	 size        => '10'
+	 },
+     fgcolor      => {
+	 default     => 'x000000',
+	 test        => $color_test,
+	 description => 'foreground color of image (x000000)',
+	 edit_type   => 'entry',
+	 size        => '10'
+	 },
+     transparent  => {
+	 default     => 'off',
+	 test        => $onoff_test, 
+	 description => 'Transparent image',
+	 edit_type   => 'onoff'
+	 },
+     grid         => {
+	 default     => 'on',
+	 test        => $onoff_test, 
+	 description => 'Display grid',
+	 edit_type   => 'onoff'
+	 },
+     border       => {
+	 default     => 'on',
+	 test        => $onoff_test, 
+	 description => 'Draw border around plot',
+	 edit_type   => 'onoff'
+	 },
+     font         => {
+	 default     => 'medium',
+	 test        => $sml_test,
+	 description => 'Size of font to use',
+	 edit_type   => 'choice',
+	 choices     => ['small','medium','large']
+	 },
+     samples         => {
+	 default     => '100',
+	 test        => $int_test,
+	 description => 'Number of samples for non-data plots',
+	 edit_type   => 'choice',
+	 choices     => ['100','200','500','1000','2000','5000']
+	 },
+     align        => {
+	 default     => 'center',
+	 test        => sub {$_[0]=~/^(left|right|center)$/},
+	 description => 'alignment for image in html',
+	 edit_type   => 'choice',
+	 choices     => ['left','right','center']
+	 },
+     texwidth     => {
+         default     => '93',
+         test        => $int_test,
+         description => 'Width of plot when printed (mm)',
+         edit_type   => 'entry',
+         size        => '5'
+         },
+     texfont     => {
+         default     => '22',
+         test        => $int_test,
+         description => 'Font size to use in TeX output (pts):',
+         edit_type   => 'choice',
+         choices     => [qw/10 12 14 16 18 20 22 24 26 28 30 32 34 36/],
+         },
+     plottype  => {
+	 default     => 'Cartesian',
+	 test        => sub {$_[0]=~/^(Polar|Cartesian)$/},
+	 description => 'Plot type:',
+	 edit_type   => 'choice',
+         choices     => ['Polar','Cartesian']
+         },
      );
 
 my %key_defaults = 
     (
-     title => { default => "on" ,        test => $onoff_test  },
-     box   => { default => "off" ,       test => $onoff_test  },
-     pos   => { default => "top right" , test => $key_pos_test}
+     title => { 
+	 default => '',
+	 test => $words_test,
+	 description => 'Title of key',
+	 edit_type   => 'entry',
+	 size        => '40'
+	 },
+     box   => { 
+	 default => 'off',
+	 test => $onoff_test,
+	 description => 'Draw a box around the key?',
+	 edit_type   => 'onoff'
+	 },
+     pos   => { 
+	 default => 'top right', 
+	 test => $key_pos_test, 
+	 description => 'position of the key on the plot',
+	 edit_type   => 'choice',
+	 choices     => ['top left','top right','bottom left','bottom right',
+			 'outside','below']
+	 }
      );
 
 my %label_defaults = 
     (
-     xpos    => {default => 0,         test => $real_test                   },
-     ypos    => {default => 0,         test => $real_test                   },
-     color   => {default => "x000000", test => $color_test                  },
-     justify => {default => "left",    
-                 test => sub {$_[0]=~/^(left|right|center)$/}}
+     xpos    => {
+	 default => 0,
+	 test => $real_test,
+	 description => 'x position of label (graph coordinates)',
+	 edit_type   => 'entry',
+	 size        => '10'
+	 },
+     ypos    => {
+	 default => 0, 
+	 test => $real_test,
+	 description => 'y position of label (graph coordinates)',
+	 edit_type   => 'entry',
+	 size        => '10'
+	 },
+     justify => {
+	 default => 'left',    
+	 test => sub {$_[0]=~/^(left|right|center)$/},
+	 description => 'justification of the label text on the plot',
+	 edit_type   => 'choice',
+	 choices     => ['left','right','center']
+     }
+     );
+
+my @tic_edit_order = ('location','mirror','start','increment','end',
+                      'minorfreq');
+my %tic_defaults =
+    (
+     location => {
+	 default => 'border', 
+	 test => sub {$_[0]=~/^(border|axis)$/},
+	 description => 'Location of major tic marks',
+	 edit_type   => 'choice',
+	 choices     => ['border','axis']
+	 },
+     mirror => {
+	 default => 'on', 
+	 test => $onoff_test,
+	 description => 'mirror tics on opposite axis?',
+	 edit_type   => 'onoff'
+	 },
+     start => {
+	 default => '-10.0',
+	 test => $real_test,
+	 description => 'Start major tics at',
+	 edit_type   => 'entry',
+	 size        => '10'
+	 },
+     increment => {
+	 default => '1.0',
+	 test => $real_test,
+	 description => 'Place a major tic every',
+	 edit_type   => 'entry',
+	 size        => '10'
+	 },
+     end => {
+	 default => ' 10.0',
+	 test => $real_test,
+	 description => 'Stop major tics at ',
+	 edit_type   => 'entry',
+	 size        => '10'
+	 },
+     minorfreq => {
+	 default => '0',
+	 test => $int_test,
+	 description => 'Number of minor tics between major tic marks',
+	 edit_type   => 'entry',
+	 size        => '10'
+	 },         
      );
 
+my @axis_edit_order = ('color','xmin','xmax','ymin','ymax');
 my %axis_defaults = 
     (
-     color     => {default => "x000000", test => $color_test},
-     thickness => {default => 1,         test => $int_test  },
-     xmin      => {default => -10.0,     test => $real_test },
-     xmax      => {default =>  10.0,     test => $real_test },
-     ymin      => {default => -10.0,     test => $real_test },
-     ymax      => {default =>  10.0,     test => $real_test }
+     color   => {
+	 default => 'x000000', 
+	 test => $color_test,
+	 description => 'color of grid lines (x000000)',
+	 edit_type   => 'entry',
+	 size        => '10'
+	 },
+     xmin      => {
+	 default => '-10.0',
+	 test => $real_test,
+	 description => 'minimum x-value shown in plot',
+	 edit_type   => 'entry',
+	 size        => '10'
+	 },
+     xmax      => {
+	 default => ' 10.0',
+	 test => $real_test,
+	 description => 'maximum x-value shown in plot',	 
+	 edit_type   => 'entry',
+	 size        => '10'
+	 },
+     ymin      => {
+	 default => '-10.0',
+	 test => $real_test,
+	 description => 'minimum y-value shown in plot',	 
+	 edit_type   => 'entry',
+	 size        => '10'
+	 },
+     ymax      => {
+	 default => ' 10.0',
+	 test => $real_test,
+	 description => 'maximum y-value shown in plot',	 
+	 edit_type   => 'entry',
+	 size        => '10'
+	 }
      );
 
+my $curve_help_text = <<"ENDCURVEHELP";
+The <b>curve</b> tag is where you set the data to be plotted by gnuplot.
+There are two ways of entering the information:
+<dl>
+    <dt> Curve Data
+    <dd> Using a <b>data</b> tag you can specify the numbers used to produce 
+the plot.  
+<p>
+By default, two <b>data</b> tags will be available in a plot.  The
+first will specify X coordinates of the data and the second will
+give the Y coordinates of the data.  When working with a linestyle that 
+requires more than two data sets, inserting another <b>data</b> tag is
+required.  Unfortunately, you must make sure the <b>data</b> tags appear
+in the order gnuplot expects the data.
+</p><p>
+Specifying the data should usually be done with a perl variable or array, 
+such as \@Xdata and \@Ydata.  You may also specify numerical data seperated 
+by commas.  Again, the order of the <b>data</b> tags is important.  The
+first tag will be the X data and the second will be the Y data.
+</p>
+    <dt> Curve Function
+    <dd> The <b>function</b> tag allows you to specify the curve to be 
+plotted as a formula that gnuplot can understand.  <b>Be careful using this
+tag.</b>  It is surprisingly easy to give gnuplot a function it cannot deal
+with properly.  Be explicit: 2*sin(2*3.141592*x/4) will work but
+2sin(2*3.141592x/4) will not.  If you do not receive any errors in the
+gnuplot data but still do not have an image produced, it is likely there
+is an error in your <b>function</b> tag.
+</dl>
+ENDCURVEHELP
+
+my @curve_edit_order = ('color','name','linestyle','pointtype','pointsize');
+
 my %curve_defaults = 
     (
-     color     => {default => "x000000", test => $color_test      },
-     name      => {default => "x000000", test => sub {$_[0]=~/^[\w ]*$/} },
-     linestyle => {default => "lines",   test => $linestyle_test  }
+     color     => {
+	 default => 'x000000',
+	 test => $color_test,
+	 description => 'color of curve (x000000)',
+	 edit_type   => 'entry',
+	 size        => '10'
+	 },
+     name      => {
+	 default => '',
+	 test => $words_test,
+	 description => 'name of curve to appear in key',
+	 edit_type   => 'entry',
+	 size        => '20'
+	 },
+     linestyle => {
+	 default => 'lines',
+	 test => $linestyle_test,
+	 description => 'Line style',
+	 edit_type   => 'choice',
+	 choices     => [keys(%linestyles)]
+	 },
+# gnuplots term=gif driver does not handle linewidth :(
+#     linewidth => {
+#         default     => 1,
+#         test        => $int_test,
+#         description => 'Line width (may not apply to all line styles)',
+#         edit_type   => 'choice',
+#         choices     => [1,2,3,4,5,6,7,8,9,10]
+#         },
+     pointsize => {
+         default     => 1,
+         test        => $pos_real_test,
+         description => 'point size (may not apply to all line styles)',
+         edit_type   => 'entry',
+         size        => '5'
+         },
+     pointtype => {
+         default     => 1,
+         test        => $int_test,
+         description => 'point type (may not apply to all line styles)',
+         edit_type   => 'choice',
+         choices     => [0,1,2,3,4,5,6]
+         }
      );
 
-##
-## End of defaults
-##
-my (%plot,%key,%axis,$title,$xlabel,$ylabel,@labels,@curves);
+###################################################################
+##                                                               ##
+##                    parsing and edit rendering                 ##
+##                                                               ##
+###################################################################
+my (%plot,%key,%axis,$title,$xlabel,$ylabel,@labels,@curves,%xtics,%ytics);
+
+sub start_gnuplot {
+    undef(%plot);   undef(%key);    undef(%axis);
+    undef($title);  undef($xlabel); undef($ylabel);
+    undef(@labels); undef(@curves);
+    undef(%xtics);  undef(%ytics);
+    #
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+    my $result='';
+    &Apache::lonxml::register('Apache::lonplot',
+	     ('title','xlabel','ylabel','key','axis','label','curve',
+	      'xtics','ytics'));
+    push (@Apache::lonxml::namespace,'lonplot');
+    if ($target eq 'web' || $target eq 'tex') {
+	&get_attributes(\%plot,\%gnuplot_defaults,$parstack,$safeeval,
+			$tagstack->[-1]);
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'GnuPlot');
+	$result .= &make_javascript();
+	$result .= &help_win($gnuplot_help_text);
+	$result .= &edit_attributes($target,$token,\%gnuplot_defaults,
+				    \@gnuplot_edit_order);
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args
+	    ($token,$parstack,$safeeval,keys(%gnuplot_defaults));
+	if ($constructtag) {
+	    $result = &Apache::edit::rebuild_tag($token);
+	}
+    }
+    return $result;
+}
 
-sub start_plot {
-    %plot = '';   %key='';    %axis=''; 
-    $title='';    $xlabel=''; $ylabel='';
-    @labels = ''; @curves='';
+sub end_gnuplot {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+    pop @Apache::lonxml::namespace;
+    &Apache::lonxml::deregister('Apache::lonplot',
+	('title','xlabel','ylabel','key','axis','label','curve'));
+    my $result = '';
+    my $randnumber;
+    # need to call rand everytime start_script would evaluate, as the
+    # safe space rand number generator and the global rand generator 
+    # are not seperate
+    if ($target eq 'web' || $target eq 'tex' || $target eq 'grade' ||
+	$target eq 'answer') {
+      $randnumber=int(rand(1000));
+    }
+    if ($target eq 'web' || $target eq 'tex') {
+	&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.'_'.$$.$randnumber.'_plot';
+	## Write the plot description to the file
+	&write_gnuplot_file($tmpdir,$filename,$target);
+	$filename = &Apache::lonnet::escape($filename);
+	## return image tag for the plot
+	if ($target eq 'web') {
+	    $result .= <<"ENDIMAGE";
+<img src    = "/cgi-bin/plot.gif?file=$filename.data&output=gif" 
+     width  = "$plot{'width'}"
+     height = "$plot{'height'}"
+     align  = "$plot{'align'}"
+     alt    = "$plot{'alttag'}" />
+ENDIMAGE
+        } elsif ($target eq 'tex') {
+	    #might be inside the safe space, register the URL for later
+	    &Apache::lonxml::register_ssi("/cgi-bin/plot.gif?file=$filename.data&output=eps");
+	    $result = '\graphicspath{{/home/httpd/perl/tmp/}}\includegraphics[width='.$plot{'texwidth'}.' mm]{'.&Apache::lonnet::unescape($filename).'.eps}';
+	}
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
+    }
+    return $result;
+}
+
+
+##--------------------------------------------------------------- xtics
+sub start_xtics {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result='';
-    #
-    &Apache::lonxml::register('Apache::plot',
-	     ('title','xlabel','ylabel','key','axis','label','curve'));
-    push (@Apache::lonxml::namespace,'plot');
-    &get_attributes(\%plot,\%plot_defaults,$parstack,$safeeval);
-    return '';
+    if ($target eq 'web' || $target eq 'tex') {
+	&get_attributes(\%xtics,\%tic_defaults,$parstack,$safeeval,
+		    $tagstack->[-1]);
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'xtics');
+	$result .= &edit_attributes($target,$token,\%tic_defaults,
+				    \@tic_edit_order);
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args
+	    ($token,$parstack,$safeeval,keys(%tic_defaults));
+	if ($constructtag) {
+	    $result = &Apache::edit::rebuild_tag($token);
+	}
+    }
+    return $result;
 }
 
-sub get_attributes{
-    %values   = %{$_[0]};
-    %defaults = %{$_[1]};
-    $parstack = $_[2];
-    $safeeval = $_[3];
-    my $attr;
-    foreach $attr (keys %defaults) {
-	$values{$attr} = &Apache::lonxml::get_param($attr,$parstack,$safeeval);
-	my $test = $defaults{$attr}->{'test'};
-	$values{$attr} = (&$test($values{$attr}) ?
-			  $values{$attr}         :
-			  $defaults{$attr}      );
+sub end_xtics {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+    my $result = '';
+    if ($target eq 'web' || $target eq 'tex') {
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
     }
-    return ;
+    return $result;
 }
 
-sub end_plot {
+##--------------------------------------------------------------- ytics
+sub start_ytics {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
-    pop @Apache::lonxml::namespace;
-    my $result;
-    ## Determine filename
-    my $filename = 
-    ## Write the plot description to the file
-    ## return image tag for the plot
+    my $result='';
+    if ($target eq 'web' || $target eq 'tex') {
+	&get_attributes(\%ytics,\%tic_defaults,$parstack,$safeeval,
+		    $tagstack->[-1]);
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'ytics');
+	$result .= &edit_attributes($target,$token,\%tic_defaults,
+				    \@tic_edit_order);
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args
+	    ($token,$parstack,$safeeval,keys(%tic_defaults));
+	if ($constructtag) {
+	    $result = &Apache::edit::rebuild_tag($token);
+	}
+    }
+    return $result;
+}
+
+sub end_ytics {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+    my $result = '';
+    if ($target eq 'web' || $target eq 'tex') {
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
+    }
     return $result;
 }
+
+
 ##----------------------------------------------------------------- key
 sub start_key {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result='';
-    &get_attributes(\%key,\%key_defaults,$parstack,$safeeval);
+    if ($target eq 'web' || $target eq 'tex') {
+	&get_attributes(\%key,\%key_defaults,$parstack,$safeeval,
+		    $tagstack->[-1]);
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Plot Key');
+	$result .= &edit_attributes($target,$token,\%key_defaults);
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args
+	    ($token,$parstack,$safeeval,keys(%key_defaults));
+	if ($constructtag) {
+	    $result = &Apache::edit::rebuild_tag($token);
+	}
+    }
     return $result;
 }
 
 sub end_key {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
+    if ($target eq 'web' || $target eq 'tex') {
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
+    }
     return $result;
 }
+
 ##------------------------------------------------------------------- title
 sub start_title {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
-    $title = &Apache::lonxml::get_all_text("/title",$$parser[-1]);
     my $result='';
+    if ($target eq 'web' || $target eq 'tex') {
+	$title = &Apache::lonxml::get_all_text("/title",$parser);
+	$title=&Apache::run::evaluate($title,$safeeval,$$parstack[-1]);
+	$title =~ s/\n/ /g;
+	if (length($title) > $max_str_len) {
+	    $title = substr($title,0,$max_str_len);
+	}
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_start($target,$token,'Plot Title');
+	my $text=&Apache::lonxml::get_all_text("/title",$parser);
+	$result.=&Apache::edit::end_row().
+	    &Apache::edit::start_spanning_row().
+	    &Apache::edit::editline('',$text,'',60);
+    } elsif ($target eq 'modified') {
+	my $text=$$parser[-1]->get_text("/title");
+	$result.=&Apache::edit::rebuild_tag($token);
+	$result.=&Apache::edit::modifiedfield($token);
+    }
     return $result;
 }
 
 sub end_title {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
+    if ($target eq 'web' || $target eq 'tex') {
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
+    }
     return $result;
 }
 ##------------------------------------------------------------------- xlabel
 sub start_xlabel {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result='';
-    $xlabel = &Apache::lonxml::get_all_text("/xlabel",$$parser[-1]);
+    if ($target eq 'web' || $target eq 'tex') {
+	$xlabel = &Apache::lonxml::get_all_text("/xlabel",$parser);
+	$xlabel=&Apache::run::evaluate($xlabel,$safeeval,$$parstack[-1]);
+	$xlabel =~ s/\n/ /g;
+	if (length($xlabel) > $max_str_len) {
+	    $xlabel = substr($xlabel,0,$max_str_len);
+	}
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_start($target,$token,'Plot Xlabel');
+	my $text=&Apache::lonxml::get_all_text("/xlabel",$parser);
+	$result.=&Apache::edit::end_row().
+	    &Apache::edit::start_spanning_row().
+	    &Apache::edit::editline('',$text,'',60);
+    } elsif ($target eq 'modified') {
+	my $text=$$parser[-1]->get_text("/xlabel");
+	$result.=&Apache::edit::rebuild_tag($token);	
+	$result.=&Apache::edit::modifiedfield($token);
+    }
     return $result;
 }
 
 sub end_xlabel {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
+    if ($target eq 'web' || $target eq 'tex') {
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
+    }
     return $result;
 }
+
 ##------------------------------------------------------------------- ylabel
 sub start_ylabel {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result='';
-    $ylabel = &Apache::lonxml::get_all_text("/ylabel",$$parser[-1]);
+    if ($target eq 'web' || $target eq 'tex') {
+	$ylabel = &Apache::lonxml::get_all_text("/ylabel",$parser);
+	$ylabel = &Apache::run::evaluate($ylabel,$safeeval,$$parstack[-1]);
+	$ylabel =~ s/\n/ /g;
+	if (length($ylabel) > $max_str_len) {
+	    $ylabel = substr($ylabel,0,$max_str_len);
+	}
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Plot Ylabel');
+	my $text = &Apache::lonxml::get_all_text("/ylabel",$parser);
+	$result .= &Apache::edit::end_row().
+	    &Apache::edit::start_spanning_row().
+	    &Apache::edit::editline('',$text,'',60);
+    } elsif ($target eq 'modified') {
+	my $text=$$parser[-1]->get_text("/ylabel");
+	$result.=&Apache::edit::rebuild_tag($token);
+	$result.=&Apache::edit::modifiedfield($token);
+    }
     return $result;
 }
 
 sub end_ylabel {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
+    if ($target eq 'web' || $target eq 'tex') {
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
+    }
     return $result;
 }
+
 ##------------------------------------------------------------------- label
 sub start_label {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result='';
-    my $label = &newhashref();
-    &get_attributes($label,\%label_defaults,$parstack,$safeeval);
-    $label->{'text'} = &Apache::lonxml::get_all_text("/label",$$parser[-1]);
-    push(@labels,$label);
+    if ($target eq 'web' || $target eq 'tex') {
+	my %label;
+	&get_attributes(\%label,\%label_defaults,$parstack,$safeeval,
+		    $tagstack->[-1]);
+	my $text = &Apache::lonxml::get_all_text("/label",$parser);
+	$text = &Apache::run::evaluate($text,$safeeval,$$parstack[-1]);
+	$text =~ s/\n/ /g;
+	$text = substr($text,0,$max_str_len) if (length($text) > $max_str_len);
+	$label{'text'} = $text;
+	push(@labels,\%label);
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Plot Label');
+	$result .= &edit_attributes($target,$token,\%label_defaults);
+	my $text = &Apache::lonxml::get_all_text("/label",$parser);
+	$result .= &Apache::edit::end_row().
+	    &Apache::edit::start_spanning_row().
+	    &Apache::edit::editline('',$text,'',60);
+    } elsif ($target eq 'modified') {
+	&Apache::edit::get_new_args
+	    ($token,$parstack,$safeeval,keys(%label_defaults));
+	$result.=&Apache::edit::rebuild_tag($token);
+	my $text=$$parser[-1]->get_text("/label");
+	$result.=&Apache::edit::modifiedfield($token);
+    }
     return $result;
 }
 
 sub end_label {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
+    if ($target eq 'web' || $target eq 'tex') {
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
+    }
     return $result;
 }
 
@@ -212,19 +790,38 @@ sub end_label {
 sub start_curve {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result='';
-    my $curve = &newhashref();
-    &get_attributes($curve,\%curve_defaults,$parstack,$safeeval);
-    push (@curves,$curve);
-    
-    &Apache::lonxml::register('Apache::plot',('function','data'));
+    &Apache::lonxml::register('Apache::lonplot',('function','data'));
     push (@Apache::lonxml::namespace,'curve');
-    
+    if ($target eq 'web' || $target eq 'tex') {
+	my %curve;
+	&get_attributes(\%curve,\%curve_defaults,$parstack,$safeeval,
+		    $tagstack->[-1]);
+	push (@curves,\%curve);
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Curve');
+	$result .= &help_win($curve_help_text);
+	$result .= &edit_attributes($target,$token,\%curve_defaults,
+                                    \@curve_edit_order);
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args
+	    ($token,$parstack,$safeeval,keys(%curve_defaults));
+	if ($constructtag) {
+	    $result = &Apache::edit::rebuild_tag($token);
+	    $result.= &Apache::edit::handle_insert();
+	}
+    }
     return $result;
 }
 
 sub end_curve {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
+    pop @Apache::lonxml::namespace;
+    &Apache::lonxml::deregister('Apache::lonplot',('function','data'));
+    if ($target eq 'web' || $target eq 'tex') {
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
+    }
     return $result;
 }
 
@@ -232,15 +829,39 @@ sub end_curve {
 sub start_function {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result='';
-
-    $curves[-1]->{'function'} = 
-	&Apache::lonxml::get_all_text("/function",$$parser[-1]);
+    if ($target eq 'web' || $target eq 'tex') {
+	if (exists($curves[-1]->{'data'})) {
+	    &Apache::lonxml::warning
+                ('Use of the <b>curve function</b> tag precludes use of '.
+                 ' the <b>curve data</b> tag.  '.
+                 'The curve data tag will be omitted in favor of the '.
+                 'curve function declaration.');
+	    delete $curves[-1]->{'data'} ;
+	}
+        my $function = &Apache::lonxml::get_all_text("/function",$parser);
+	$function = &Apache::run::evaluate($function,$safeeval,$$parstack[-1]);
+	$curves[-1]->{'function'} = $function; 
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Gnuplot compatible curve function');
+	my $text = &Apache::lonxml::get_all_text("/function",$parser);
+	$result .= &Apache::edit::end_row().
+	    &Apache::edit::start_spanning_row().
+	    &Apache::edit::editline('',$text,'',60);
+    } elsif ($target eq 'modified') {
+	$result.=&Apache::edit::rebuild_tag($token);
+	my $text=$$parser[-1]->get_text("/function");
+	$result.=&Apache::edit::modifiedfield($token);
+    }
     return $result;
 }
 
 sub end_function {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
+    if ($target eq 'web' || $target eq 'tex') {
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::end_table();
+    }
     return $result;
 }
 
@@ -248,14 +869,77 @@ sub end_function {
 sub start_data {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result='';
-    push( @{$curves[-1]->{'data'}},
-	  &Apache::lonxml::get_all_text("/data",$$parser[-1]));
+    if ($target eq 'web' || $target eq 'tex') {
+	if (exists($curves[-1]->{'function'})) {
+	    &Apache::lonxml::warning
+                ('Use of the <b>curve function</b> tag precludes use of '.
+                 ' the <b>curve data</b> tag.  '.
+                 'The curve function tag will be omitted in favor of the '.
+                 'curve data declaration.');
+	    delete($curves[-1]->{'function'});
+	}
+	my $datatext = &Apache::lonxml::get_all_text("/data",$parser);
+	$datatext=&Apache::run::evaluate($datatext,$safeeval,$$parstack[-1]);
+	# Deal with cases where we're given an array...
+	if ($datatext =~ /^\@/) {
+	    $datatext = &Apache::run::run('return "'.$datatext.'"',
+					  $safeeval,1);
+	}
+	$datatext =~ s/\s+/ /g;
+	# Need to do some error checking on the @data array - 
+	# make sure it's all numbers and make sure each array 
+	# is of the same length.
+	my @data;
+	if ($datatext =~ /,/) { # comma deliminated
+	    @data = split /,/,$datatext;
+	} else { # Assume it's space seperated.
+	    @data = split / /,$datatext;
+	}
+	for (my $i=0;$i<=$#data;$i++) {
+	    # Check that it's non-empty
+	    if (! defined($data[$i])) {
+		&Apache::lonxml::warning(
+		    'undefined curve data value.  Replacing with '.
+		    ' pi/e = 1.15572734979092');
+		$data[$i] = 1.15572734979092;
+	    }
+	    # Check that it's a number
+	    if (! &$real_test($data[$i]) & ! &$int_test($data[$i])) {
+		&Apache::lonxml::warning(
+		    'Bad curve data value of '.$data[$i].'  Replacing with '.
+		    ' pi/e = 1.15572734979092');
+		$data[$i] = 1.15572734979092;
+	    }
+	}
+	# 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]}})){
+	    &Apache::lonxml::warning
+		('Number of data points is not consistent with previous '.
+		 'number of data points');
+	}
+	push  @{$curves[-1]->{'data'}},\@data;
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Comma or space deliminated curve data');
+	my $text = &Apache::lonxml::get_all_text("/data",$parser);
+	$result .= &Apache::edit::end_row().
+	    &Apache::edit::start_spanning_row().
+	    &Apache::edit::editline('',$text,'',60);
+    } elsif ($target eq 'modified') {
+	$result.=&Apache::edit::rebuild_tag($token);
+	my $text=$$parser[-1]->get_text("/data");
+	$result.=&Apache::edit::modifiedfield($token);
+    }
     return $result;
 }
 
 sub end_data {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
+    if ($target eq 'web' || $target eq 'tex') {
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::end_table();
+    }
     return $result;
 }
 
@@ -263,22 +947,439 @@ sub end_data {
 sub start_axis {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result='';
-    &get_attributes(\%axis,\%label_defaults,$parstack,$safeeval);
+    if ($target eq 'web' || $target eq 'tex') {
+	&get_attributes(\%axis,\%axis_defaults,$parstack,$safeeval,
+			$tagstack->[-1]);
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Plot Axes');
+	$result .= &edit_attributes($target,$token,\%axis_defaults,
+				    \@axis_edit_order);
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args
+	    ($token,$parstack,$safeeval,keys(%axis_defaults));
+	if ($constructtag) {
+	    $result = &Apache::edit::rebuild_tag($token);
+	}
+    }
     return $result;
 }
 
 sub end_axis {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
+    if ($target eq 'web' || $target eq 'tex') {
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
+    } elsif ($target eq 'modified') {
+    }
     return $result;
 }
 
+###################################################################
+##                                                               ##
+##        Utility Functions                                      ##
+##                                                               ##
+###################################################################
+
+##----------------------------------------------------------- set_defaults
+sub set_defaults {
+    my ($var,$defaults) = @_;
+    my $key;
+    foreach $key (keys(%$defaults)) {
+	$var->{$key} = $defaults->{$key}->{'default'};
+    }
+}
+
 ##------------------------------------------------------------------- misc
-sub newhashref{
-    my %hash;
-    return \%hash;
+sub get_attributes{
+    my ($values,$defaults,$parstack,$safeeval,$tag) = @_;
+    foreach my $attr (keys(%{$defaults})) {
+	if ($attr eq 'texwidth' || $attr eq 'texfont') {
+	    $values->{$attr} = 
+		&Apache::lonxml::get_param($attr,$parstack,$safeeval,undef,1);
+	} else {
+	    $values->{$attr} = 
+		&Apache::lonxml::get_param($attr,$parstack,$safeeval);
+	}
+	if ($values->{$attr} eq '' | !defined($values->{$attr})) {
+	    $values->{$attr} = $defaults->{$attr}->{'default'};
+	    next;
+	}
+	my $test = $defaults->{$attr}->{'test'};
+	if (! &$test($values->{$attr})) {
+	    &Apache::lonxml::warning
+		($tag.':'.$attr.': Bad value.'.'Replacing your value with : '
+		 .$defaults->{$attr}->{'default'} );
+	    $values->{$attr} = $defaults->{$attr}->{'default'};
+	}
+    }
+    return ;
+}
+
+##------------------------------------------------------- write_gnuplot_file
+sub write_gnuplot_file {
+    my ($tmpdir,$filename,$target)= @_;
+    my $gnuplot_input = '';
+    my $curve;
+    my $pt = $plot{'texfont'};
+    # Collect all the colors
+    my @Colors;
+    push @Colors, $plot{'bgcolor'};
+    push @Colors, $plot{'fgcolor'}; 
+    push @Colors, (defined($axis{'color'})?$axis{'color'}:$plot{'fgcolor'});
+    foreach $curve (@curves) {
+	push @Colors, ($curve->{'color'} ne '' ? 
+		       $curve->{'color'}       : 
+		       $plot{'fgcolor'}        );
+    }
+    # set term
+    if ($target eq 'web') {
+	$gnuplot_input .= 'set term gif ';
+	$gnuplot_input .= 'transparent ' if ($plot{'transparent'} eq 'on');
+	$gnuplot_input .= $plot{'font'} . ' ';
+	$gnuplot_input .= 'size '.$plot{'width'}.','.$plot{'height'}.' ';
+	$gnuplot_input .= "@Colors\n";
+	# set output
+	$gnuplot_input .= "set output\n";
+    } elsif ($target eq 'tex') {
+	$gnuplot_input .= "set term postscript eps monochrome solid \"Helvetica\" $pt \n";
+	$gnuplot_input .= "set output \"/home/httpd/perl/tmp/".
+	    &Apache::lonnet::unescape($filename).".eps\"\n";
+    }
+    # cartesian or polar?
+    if (lc($plot{'plottype'}) eq 'polar') {
+        $gnuplot_input .= 'set polar'.$/;
+    } else {
+        # Assume Cartesian
+    }
+    # grid
+    $gnuplot_input .= 'set grid'.$/ if ($plot{'grid'} eq 'on');
+    # border
+    $gnuplot_input .= ($plot{'border'} eq 'on'?
+		       'set border'.$/           :
+		       'set noborder'.$/         );
+    # sampling rate for non-data curves
+    $gnuplot_input .= "set samples $plot{'samples'}\n";
+    # title, xlabel, ylabel
+    # titles
+    if ($target eq 'tex') {
+        $gnuplot_input .= "set title  \"$title\" font \"Helvetica,".$pt."pt\"\n"  if (defined($title)) ;
+        $gnuplot_input .= "set xlabel \"$xlabel\" font \"Helvetica,".$pt."pt\" \n" if (defined($xlabel));
+        $gnuplot_input .= "set ylabel \"$ylabel\" font \"Helvetica,".$pt."pt\"\n" if (defined($ylabel));
+    } else {
+        $gnuplot_input .= "set title  \"$title\"  \n"  if (defined($title)) ;
+        $gnuplot_input .= "set xlabel \"$xlabel\" \n" if (defined($xlabel));
+        $gnuplot_input .= "set ylabel \"$ylabel\" \n" if (defined($ylabel));
+    }
+    # tics
+    if (%xtics) {    
+	$gnuplot_input .= "set xtics $xtics{'location'} ";
+	$gnuplot_input .= ( $xtics{'mirror'} eq 'on'?"mirror ":"nomirror ");
+	$gnuplot_input .= "$xtics{'start'}, ";
+	$gnuplot_input .= "$xtics{'increment'}, ";
+	$gnuplot_input .= "$xtics{'end'}\n";
+        if ($xtics{'minorfreq'} != 0) {
+            $gnuplot_input .= "set mxtics ".$xtics{'minorfreq'}."\n";
+        } 
+    }
+    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";
+        if ($ytics{'minorfreq'} != 0) {
+            $gnuplot_input .= "set mytics ".$ytics{'minorfreq'}."\n";
+        } 
+    }
+    # axis
+    if (%axis) {
+	$gnuplot_input .= "set xrange \[$axis{'xmin'}:$axis{'xmax'}\]\n";
+	$gnuplot_input .= "set yrange \[$axis{'ymin'}:$axis{'ymax'}\]\n";
+    }
+    # Key
+    if (%key) {
+	$gnuplot_input .= 'set key '.$key{'pos'}.' ';
+	if ($key{'title'} ne '') {
+	    $gnuplot_input .= 'title "'.$key{'title'}.'" ';
+	} 
+	$gnuplot_input .= ($key{'box'} eq 'on' ? 'box ' : 'nobox ').$/;
+    } else {
+	$gnuplot_input .= 'set nokey'.$/;
+    }
+    # labels
+    my $label;
+    foreach $label (@labels) {
+	$gnuplot_input .= 'set label "'.$label->{'text'}.'" at '.
+	    $label->{'xpos'}.','.$label->{'ypos'}.' '.$label->{'justify'}.' font "Helvetica,'.$pt.'pt"'.$/ ;
+    }
+    if ($target eq 'tex') {
+        $gnuplot_input .="set size 1,".$plot{'height'}/$plot{'width'}*1.38;
+        $gnuplot_input .="\n";
+        }
+    # curves
+    $gnuplot_input .= 'plot ';
+    for (my $i = 0;$i<=$#curves;$i++) {
+	$curve = $curves[$i];
+	$gnuplot_input.= ', ' if ($i > 0);
+	if (exists($curve->{'function'})) {
+	    $gnuplot_input.= 
+		$curve->{'function'}.' title "'.
+		$curve->{'name'}.'" with '.
+                $curve->{'linestyle'};
+            $gnuplot_input.= ' linewidth 4 ' if ($target eq 'tex');
+            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 (exists($curve->{'data'})) {
+	    # Store data values in $datatext
+	    my $datatext = '';
+	    #   get new filename
+	    my $datafilename = "$tmpdir/$filename.data.$i";
+	    my $fh=Apache::File->new(">$datafilename");
+	    # Compile data
+	    my @Data = @{$curve->{'data'}};
+	    my @Data0 = @{$Data[0]};
+	    for (my $i =0; $i<=$#Data0; $i++) {
+		my $dataset;
+		foreach $dataset (@Data) {
+		    $datatext .= $dataset->[$i] . ' ';
+		}
+		$datatext .= $/;
+	    }
+	    #   write file
+	    print $fh $datatext;
+	    close ($fh);
+	    #   generate gnuplot text
+	    $gnuplot_input.= '"'.$datafilename.'" title "'.
+		$curve->{'name'}.'" with '.
+		$curve->{'linestyle'};
+            $gnuplot_input.= ' linewidth 4 ' if ($target eq 'tex');
+            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'};
+            }
+	}
+    }
+    # Write the output to a file.
+    my $fh=Apache::File->new(">$tmpdir$filename.data");
+    print $fh $gnuplot_input;
+    close($fh);
+    # That's all folks.
+    return ;
+}
+
+#---------------------------------------------- check_inputs
+sub check_inputs {
+    ## Note: no inputs, no outputs - this acts only on global variables.
+    ## Make sure we have all the input we need:
+    if (! %plot) { &set_defaults(\%plot,\%gnuplot_defaults); }
+    if (! %key ) {} # No key for this plot, thats okay
+#    if (! %axis) { &set_defaults(\%axis,\%axis_defaults); }
+    if (! defined($title )) {} # No title for this plot, thats okay
+    if (! defined($xlabel)) {} # No xlabel for this plot, thats okay
+    if (! defined($ylabel)) {} # No ylabel for this plot, thats okay
+    if ($#labels < 0) { }      # No labels for this plot, thats okay
+    if ($#curves < 0) { 
+	&Apache::lonxml::warning("No curves specified for plot!!!!");
+	return '';
+    }
+    my $curve;
+    foreach $curve (@curves) {
+	if (!defined($curve->{'function'})&&!defined($curve->{'data'})){
+	    &Apache::lonxml::warning("One of the curves specified did not contain any curve data or curve function declarations\n");
+	    return '';
+	}
+    }
+}
+
+#------------------------------------------------ make_edit
+sub edit_attributes {
+    my ($target,$token,$defaults,$keys) = @_;
+    my ($result,@keys);
+    if ($keys && ref($keys) eq 'ARRAY') {
+        @keys = @$keys;
+    } else {
+	@keys = sort(keys(%$defaults));
+    }
+    foreach my $attr (@keys) {
+	# append a ' ' to the description if it doesn't have one already.
+	my $description = $defaults->{$attr}->{'description'};
+	$description .= ' ' if ($description !~ / $/);
+	if ($defaults->{$attr}->{'edit_type'} eq 'entry') {
+	    $result .= &Apache::edit::text_arg
+		($description,$attr,$token,
+		 $defaults->{$attr}->{'size'});
+	} elsif ($defaults->{$attr}->{'edit_type'} eq 'choice') {
+	    $result .= &Apache::edit::select_arg
+		($description,$attr,$defaults->{$attr}->{'choices'},$token);
+	} elsif ($defaults->{$attr}->{'edit_type'} eq 'onoff') {
+	    $result .= &Apache::edit::select_arg
+		($description,$attr,['on','off'],$token);
+	}
+	$result .= '<br />';
+    }
+    return $result;
+}
+
+
+###################################################################
+##                                                               ##
+##           Insertion functions for editing plots               ##
+##                                                               ##
+###################################################################
+
+sub insert_gnuplot {
+    my $result = '';
+    #  plot attributes
+    $result .= "\n<gnuplot ";
+    foreach my $attr (keys(%gnuplot_defaults)) {
+	$result .= "\n     $attr=\"$gnuplot_defaults{$attr}->{'default'}\"";
+    }
+    $result .= ">";
+    # Add the components (most are commented out for simplicity)
+    # $result .= &insert_key();
+    # $result .= &insert_axis();
+    # $result .= &insert_title();    
+    # $result .= &insert_xlabel();    
+    # $result .= &insert_ylabel();    
+    $result .= &insert_curve();
+    # close up the <gnuplot>
+    $result .= "\n</gnuplot>";
+    return $result;
+}
+
+sub insert_tics {
+    my $result;
+    $result .= &insert_xtics() . &insert_ytics;
+    return $result;
+}
+
+sub insert_xtics {
+    my $result;
+    $result .= "\n    <xtics ";
+    foreach my $attr (keys(%tic_defaults)) {
+	$result .= "\n        $attr=\"$tic_defaults{$attr}->{'default'}\" ";
+    }
+    $result .= "/>";
+    return $result;
+}
+
+sub insert_ytics {
+    my $result;
+    $result .= "\n    <ytics ";
+    foreach my $attr (keys(%tic_defaults)) {
+	$result .= "\n        $attr=\"$tic_defaults{$attr}->{'default'}\" ";
+    }
+    $result .= "/>";
+    return $result;
 }
 
+sub insert_key {
+    my $result;
+    $result .= "\n    <key ";
+    foreach my $attr (keys(%key_defaults)) {
+	$result .= "\n         $attr=\"$key_defaults{$attr}->{'default'}\"";
+    }
+    $result .= " />";
+    return $result;
+}
 
+sub insert_axis{
+    my $result;
+    $result .= "\n    <axis ";
+   foreach my $attr (keys(%axis_defaults)) {
+	$result .= "\n         $attr=\"$axis_defaults{$attr}->{'default'}\"";
+    }
+    $result .= " />";
+    return $result;
+}
+
+sub insert_title  { return "\n    <title></title>"; }
+sub insert_xlabel { return "\n    <xlabel></xlabel>"; }
+sub insert_ylabel { return "\n    <ylabel></ylabel>"; }
+
+sub insert_label {
+    my $result;
+    $result .= "\n    <label ";
+    foreach my $attr (keys(%label_defaults)) {
+	$result .= "\n         $attr=\"".
+            $label_defaults{$attr}->{'default'}."\"";
+    }
+    $result .= "></label>";
+    return $result;
+}
+
+sub insert_curve {
+    my $result;
+    $result .= "\n    <curve ";
+    foreach my $attr (keys(%curve_defaults)) {
+	$result .= "\n         $attr=\"".
+	    $curve_defaults{$attr}->{'default'}."\"";
+    }
+    $result .= " >";
+    $result .= &insert_data().&insert_data()."\n    </curve>";
+}
+
+sub insert_function {
+    my $result;
+    $result .= "\n        <function></function>";
+    return $result;
+}
+
+sub insert_data {
+    my $result;
+    $result .= "\n        <data></data>";
+    return $result;
+}
+
+##----------------------------------------------------------------------
+# Javascript functions to display help for tags
+
+sub make_javascript {
+    my $helpwindowwidth  = 400;
+    my $helpwindowheight = 400;
+    my $result = '';
+    $result.=<<"ENDFUNCTION";
+<script language="JavaScript">
+function openWin(text)
+{
+  newWin = open("", "new_W", "width=$helpwindowwidth,height=$helpwindowheight,resizable=1,scrollbars=1");
+  newWin.document.open("text/html", "replace");
+  newWin.document.writeln(text);
+  newWin.document.writeln('<center><a href=\"javascript:window.close()\">close this window</a></center>');
+  newWin.document.close();
+}
+</script>
+ENDFUNCTION
+    return $result;
+}
+
+sub help_win {
+    my ($helptext)=@_;
+    $helptext =~ s/\n/ /g;
+    $helptext =~ s/\'/\\\'/g;
+    my $result = '';
+    $result.=<<"ENDWIN";
+<table width="100%"><tr><td align="right">
+<a href="javascript:openWin('$helptext')">help</a>
+</td></tr></table><hr />
+ENDWIN
+    return $result;
+}
+##----------------------------------------------------------------------
 1;
 __END__
+
+