Added --style.

Use Pod::Usage.
Improved doc.

tsplotv

@@ -4,24 +4,53 @@
 
 tsplotv - plot time series given in vertical format
 
+=head1 SYNOPSIS
+
+tsplotv
+[--legend-position pos]
+[--output-format format ]
+[--stacked]
+[--style style]
+[file ...]
+
 =head1 DESCRIPTION
 
 This program expects time series data in vertical format, I.e.,
 each line contains a tripel <time, series, value>. 
 
+The default legend position is "top right", same as with gnuplot.
+Another frequently useful position (especially if you have lots of series)
+is "below. Note that positions which consist of several world (such as
+"top right" need to be passed to tsplotv as a single argument, so the 
+space needs to be hidden from the shell by use of quotes or a backslash.
+
+The default output format is "png", the default style is "lines".
+
+See L<TimeSeries> for a description of possible legend positions,
+output formats, and styles.
+
+The --stacked option causes the time series to be stacked on top of each
+other.
+
 =cut
 
 use strict;
 use TimeSeries;
 use Getopt::Long;
+use Pod::Usage;
 
+my $help;
+my $legend_position = 'top right';
 my $output_format ='png';
 my $stacked = 0;
-my $legend_position = 'top right';
-GetOptions('output_format|output-format=s' => \$output_format,
-	   'stacked' => \$stacked,
+my $style = "lines";
+GetOptions('help|?' => \$help,
 	   'legend_position|legend-position=s' => \$legend_position,
-) or die "Usage: $0 [--output_format format] [files...]\n";
+	   'output_format|output-format=s' => \$output_format,
+	   'stacked' => \$stacked,
+	   'style:s' => \$style,
+	  ) or pod2usage(2);
+pod2usage(1) if $help;
 
 
 binmode STDOUT, ':raw';
@@ -41,6 +70,8 @@ my @series = sort { $series{$a} <=> $series{$b} } keys %series;
 $ts->legend(@series);
 $ts->legend_position($legend_position);
 $ts->stacked($stacked);
+$ts->style($style);
+
 for my $timestamp (sort keys %data) {
     my %d = %{$data{$timestamp}};
     my @values = @d{@series};