--- loncom/xml/lonplot.pm	2002/02/05 15:05:44	1.47
+++ loncom/xml/lonplot.pm	2002/02/06 10:24:55	1.48
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Dynamic plot
 #
-# $Id: lonplot.pm,v 1.47 2002/02/05 15:05:44 matthew Exp $
+# $Id: lonplot.pm,v 1.48 2002/02/06 10:24:55 matthew Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -29,7 +29,7 @@
 # 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 Matthew
+# 01/21 02/05 Matthew
 
 package Apache::lonplot;
 
@@ -115,6 +115,37 @@ my $words_test     = sub {$_[0]=~s/\s+/
 ###################################################################
 my @gnuplot_edit_order = 
     qw/bgcolor fgcolor height width font transparent grid border align/;
+
+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>
+ENDPLOTHELP
+
 my %gnuplot_defaults = 
     (
      height       => {
@@ -307,6 +338,37 @@ my %axis_defaults =
 	 }
      );
 
+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.  Be careful using this
+tag - 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_defaults = 
     (
      color     => {
@@ -359,6 +421,8 @@ sub start_gnuplot {
 			$tagstack->[-1]);
     } elsif ($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') {
@@ -644,6 +708,7 @@ sub start_curve {
 	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,$token,\%curve_defaults);
     } elsif ($target eq 'modified') {
 	my $constructtag=&Apache::edit::get_new_args
@@ -1122,6 +1187,40 @@ sub insert_data {
 }
 
 ##----------------------------------------------------------------------
+# 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__