--- loncom/xml/lonplot.pm	2012/07/03 11:29:57	1.156
+++ loncom/xml/lonplot.pm	2012/07/17 10:49:53	1.162
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Dynamic plot
 #
-# $Id: lonplot.pm,v 1.156 2012/07/03 11:29:57 foxr Exp $
+# $Id: lonplot.pm,v 1.162 2012/07/17 10:49:53 foxr Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -98,11 +98,16 @@ BEGIN {
 my $max_str_len = 50;    # if a label, title, xlabel, or ylabel text
                          # is longer than this, it will be truncated.
 
-my %linetypes =
+my %linetypes =			# For png use these linetypes.
     (
      solid          => 1,
      dashed         => 0
     );
+my %ps_linetypes = 		# For ps the line types are different!
+   (
+    solid          => 0,
+    dashed         => 7
+   );
 
 my %linestyles = 
     (
@@ -134,6 +139,10 @@ my $sml_test       = sub {$_[0]=~/^(\d+|
 my $linestyle_test = sub {exists($linestyles{$_[0]})};
 my $words_test     = sub {$_[0]=~s/\s+/ /g;$_[0]=~/^([\w~!\@\#\$\%^&\*\(\)-=_\+\[\]\{\}:\;\'<>,\.\/\?\\]+ ?)+$/};
 
+my $arrowhead_test = sub{$_[0]=~/^(nohead|head|heads| )+$/};
+my $arrowstyle_test= sub{$_[0]=~/^(filled|empty|nofilled)+$/};
+my $degree_test  = sub{&$pos_real_test($_[0]) && ($_[0] <= 360.0)};
+
 ###################################################################
 ##                                                               ##
 ##                      Attribute metadata                       ##
@@ -528,7 +537,10 @@ my %axis_defaults =
      	},
      );
 
-my @curve_edit_order = ('color','name','linestyle','linewidth','linetype','pointtype','pointsize','limit');
+my @curve_edit_order = ('color','name','linestyle','linewidth','linetype',
+			'pointtype','pointsize','limit', 'arrowhead', 'arrowstyle', 
+			'arrowlength', 'arrowangle', 'arrowbackangle'
+    );
 
 my %curve_defaults = 
     (
@@ -589,6 +601,43 @@ my %curve_defaults =
          edit_type   => 'choice',
          choices     => ['above', 'below', 'closed','x1','x2','y1','y2']
          },
+     arrowhead => {
+         default     => 'head',
+	 test        => $arrowhead_test,
+	 description => 'Vector arrow head type',
+	 edit_type   => 'choice',
+	 choices     => ['nohead', 'head', 'heads']
+     },
+     arrowstyle => {
+	 default     => 'filled',
+	 test        => $arrowstyle_test,
+	 description => 'Vector arrow head style',
+	 edit_type   => 'choice',
+	 choices     => ['filled', 'empty', 'nofilled']
+     },
+     arrowlength => {
+	 default     => 0.02,
+	 test        => $pos_real_test,
+	 description => "Length of vector arrow (only applies to vector plots)",
+	 edit_type   => 'entry',
+	 size        => '5'
+     },
+     arrowangle  => {
+	default      => 10.0,
+	test         => $degree_test,
+	description  => 'Angle of arrow branches to arrow body (only applies to vector plots)',
+	edit_type    => 'entry',
+	size         => '5'
+     },
+
+     arrowbackangle => {
+	 default    => 90.0,
+	 test       => $degree_test,
+	 descripton => 'Angle of arrow back lines to branches.',
+	 edit_type  => 'entry',
+	 size       => '5'
+     }
+
      );
 
 ###################################################################
@@ -1587,6 +1636,48 @@ sub get_attributes{
     }
     return ;
 }
+##
+# Generate tic mark specifications.
+# 
+# @param type - type of tics (xtics or ytics).
+# @param spec - Reference to a hash that contains the tic specification.
+# @param target - 'tex' if hard copy target.
+#
+# @return string - the tic specification command.
+#
+sub generate_tics {
+    my ($type, $spec, $target) = @_;
+    my $result   = '';
+
+
+    if (defined %$spec) {
+
+
+
+	# Major tics:
+
+	$result .= "set $type $spec->{'location'}  ";
+	$result .= ($spec->{'mirror'} eq 'on') ? 'mirror ' : 'nomirror ';
+	$result .= "$spec->{'start'}, ";
+	$result .= "$spec->{'increment'}, ";
+	$result .= "$spec->{'end'} ";
+	if ($target eq 'tex' ) {
+	    $result .= 'font "Helvetica,22"';
+	}
+	$result .= "\n";
+
+	# minor frequency:
+
+	if ($spec->{'minorfreq'} != 0) {
+	    $result .= "set m$type $spec->{'minorfreq'}\n";
+	}
+    } else {
+	$result .= "set $type font " . '"Helvetica,22"' ."\n";
+    }
+
+
+    return $result;
+}
 
 ##------------------------------------------------------- write_gnuplot_file
 sub write_gnuplot_file {
@@ -1648,6 +1739,7 @@ sub write_gnuplot_file {
 	$gnuplot_input .= "set encoding iso_8859_1\n"; # Get access to extended font.
 
     }
+    $gnuplot_input .= "set encoding utf8\n";
     # cartesian or polar plot?
     if (lc($Apache::lonplot::plot{'plottype'}) eq 'polar') {
         $gnuplot_input .= 'set polar'.$/;
@@ -1728,42 +1820,10 @@ sub write_gnuplot_file {
         $gnuplot_input .= "set ylabel \"$ylabel\" $extra_space_y \n" if (defined($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'} ";
-	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'} ";
-        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.
-	}
-    }
+    $gnuplot_input .= &generate_tics('xtics', \%xtics, $target);
+
+    $gnuplot_input .= &generate_tics('ytics', \%ytics, $target);
+
     # axis
     if (%axis) {
         if ($axis{'xformat'} ne 'on') {
@@ -1842,10 +1902,13 @@ sub write_gnuplot_file {
     #  type (solid/dashed), color, width
     #
     my $linestyle_index = 50;
-    my $line_type    = '';     
-    my $line_color   = '';
     my $line_width   = '';
 
+    # If arrows are needed there will be an arrow style for each as well:
+    #
+
+    my $arrow_style_index = 50;
+
     my $plot_command;
     my $plot_type;
 
@@ -1855,6 +1918,7 @@ sub write_gnuplot_file {
 	if ($target eq 'tex') {
 	    $curve->{'linewidth'} *= 2;
 	}
+	$line_width = $curve->{'linewidth'};
 	if (exists($curve->{'function'})) {
 	    $plot_type    = 
 		$curve->{'function'}.' title "'.
@@ -1884,31 +1948,75 @@ sub write_gnuplot_file {
 		$curve->{'name'}.'" with '.
 		$curve->{'linestyle'};
 	}
+	my $pointtype = '';
+	my $pointsize = '';
+
+	# Figure out the linestyle:
+
+	my $lt = $curve->{'linetype'} ne '' ? $curve->{'linetype'} 
+	                : 'solid';	# Line type defaults to solid.
+	# The mapping of lt -> the actual gnuplot line type depends on the target:
+
+	if ($target eq 'tex') {
+	    $lt = $ps_linetypes{$lt};
+	} else {
+	    $lt = $linetypes{$lt}
+	}
+
+	my $color = $curve->{'color'};
+	$color =~ s/^x/#/;	        # Convert xhex color -> #hex color.   
+
+	my $style_command = "set style line $linestyle_index $pointtype $pointsize linetype $lt linewidth $line_width lc rgb '$color'\n";
+	$gnuplot_input .= $style_command;
+
+
+
 	if (($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'};
+	    
+	    $pointtype =' pointtype '.$curve->{'pointtype'};
+	    $pointsize =' pointsize '.$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.= $curve->{'color'}.'"';
+	} elsif ($curve->{'linestyle'} eq 'vector') {
+
+	    # Create the arrow head style add it to 
+	    # $gnuplot_input..and ensure it gets
+	    # Selected in the plot command.
+
+	    $gnuplot_input .= "set style arrow $arrow_style_index ";
+	    $gnuplot_input .= ' ' . $curve->{'arrowhead'};
+	    $gnuplot_input .= ' size ' . $curve->{'arrowlength'};
+	    $gnuplot_input .= ','.$curve->{'arrowangle'};
+	    $gnuplot_input .= ',' . $curve->{'arrowbackangle'}; 
+	    $gnuplot_input .=  ' ' . $curve->{'arrowstyle'} . " ls $linestyle_index\n";
+
+
+	    $plot_command  .= "  arrowstyle $arrow_style_index ";
+	    $arrow_style_index++;
+	}
+
+
+
+
+	# The condition below is because gnuplot lumps the linestyle in with the 
+	# arrowstyle _sigh_.
+
+	if ($curve->{'linestyle'} ne 'vector') {
+	    $plot_command.= " ls $linestyle_index";
 	}
-	$plot_command.= ' linewidth '.$curve->{'linewidth'};
+
 	$gnuplot_input .= 'plot ' . $plot_type . ' ' . $plot_command . "\n";
+	$linestyle_index++;	# Each curve get a unique linestyle.
     }
     # Write the output to a file.
-    open (my $fh,">$tmpdir$filename.data");
-    binmode($fh, ":utf8");
+    &Apache::lonnet::logthis($gnuplot_input);
+    open (my $fh, "> $tmpdir$filename.data");
+    binmode($fh, ':utf8');
     print $fh $gnuplot_input;
     close($fh);
     # That's all folks.