use strict; 
use Chart::Gnuplot; 

# Date array 
my @x = qw( 2007-01-01 
            2007-01-10 
            2007-01-24 
            2007-02-01 
            2007-02-14 ); 
my @b = ([1, 2, 3, 4, 5],
	 [6, 7, 8, 9, 10]);
my @p;
my @n;

# Create the chart object 
my $chart = Chart::Gnuplot->new( output => 'datetime_1.png', xlabel => 'Date axis', timeaxis => "x", ); 

# Data set object 
for my $i ( 1 .. 1) {
      @n = (); 
      for my $j ( 0 .. $#{$b[$i]}) {
      print "b[$i][$j] is $b[$i][$j]\n";
      push(@n,$b[$i][$j]);
      }
      
      my $plot = Chart::Gnuplot::DataSet->new( 
          xdata => \@x, 
          ydata => \@n, 
          style => 'linespoints', 
          timefmt => '%Y-%m-%d', );
     
      $chart->plot2d($plot);
}

##</code><code>##

$chart->plot2d($val1) if $val == 1;
$chart->plot2d($val1,$val2) if $val == 2;
$chart->plot2d($val1,$val2,$val3) if $val == 3;
etc...