make_before_label_histgram.pl

use strict;
use GD::Graph::bars;
use Path::Class qw(dir); 

my $dir = dir('.');
my $handle = $dir->open;

while (my $file = $handle->read) {
    next unless $_ =‾ /log$/;

    my $data = get_data($filename);
    make_graph($data, $filename, "'Before' state histgram", 'before state', 'person number');
}

sub get_data {
    my $filename = shift;
    open(my $fh, $filename); 

    my @labels;
    my @dataset;
    while(<$fh>) {
       next if $_ =‾ /^#/; 

       my @strs = split ',', $_;
       push @labels, $strs[0];
       $strs[1] =‾ s/¥s*$//;
       push @dataset, $strs[1];
    }
    my @data    = ( ¥@labels, ¥@dataset);
    return ¥@data;
}

sub make_graph {
    my ($data, $filename, $title, $x_label, $y_label) = @_;

    my $graph = GD::Graph::bars->new( 800, 600 );
    $graph->set(title   => $title,
                x_label => $x_label,
                y_label => $y_label);
                
    $graph->set_title_font( "GOTHIC_FONT", 14 );
    $graph->set_legend_font( "GOTHIC_FONT", 8 );
    $graph->set_x_axis_font( "GOTHIC_FONT", 8 );
    $graph->set_x_label_font( "GOTHIC_FONT", 10 );
    $graph->set_y_axis_font( "GOTHIC_FONT", 8 );
    $graph->set_y_label_font( "GOTHIC_FONT", 8 );

    my $image = $graph->plot( $data );

    open( OUT, "> $filename.jpg") or die( "Cannot open file: $filename.jpg" );
    binmode OUT;
    print OUT $image->jpeg();
    close OUT;
}

make_staytime_histgram.pl

use strict;
use GD::Graph::bars;

my $filename = $ARGV[0];
if (!$filename) {
   die('please input data filename.');
} 
    
my $graph_filename = $ARGV[1] ? $ARGV[1] : 'graph';

my $data = get_data($filename);
make_graph($data, $graph_filename, 'stay time histgram (stay near bench)', 'stay duration(second)', 'stayed person number');

sub get_data {
    my $filename = shift;
    open(my $fh, $filename); 

    my @labels;
    my @dataset;
    while(<$fh>) {
       my @strs = split ',', $_;
       push @labels, $strs[0];
       $strs[1] =‾ s/¥s*$//;
       push @dataset, $strs[1];
    }
    my @data    = ( ¥@labels, ¥@dataset);
    return ¥@data;
}

sub make_graph {
    my ($data, $filename, $title, $x_label, $y_label) = @_;

    my $graph = GD::Graph::bars->new( 800, 600 );
    $graph->set(title   => $title,
                x_label => $x_label,
                y_label => $y_label);
                
    $graph->set_title_font( "GOTHIC_FONT", 14 );
    $graph->set_legend_font( "GOTHIC_FONT", 8 );
    $graph->set_x_axis_font( "GOTHIC_FONT", 8 );
    $graph->set_x_label_font( "GOTHIC_FONT", 10 );
    $graph->set_y_axis_font( "GOTHIC_FONT", 8 );
    $graph->set_y_label_font( "GOTHIC_FONT", 8 );

    my $image = $graph->plot( $data );

    open( OUT, "> $filename.jpg") or die( "Cannot open file: $filename.jpg" );
    binmode OUT;
    print OUT $image->jpeg();
    close OUT;
}