色々日記（ざ・めも）

■GD::Graphの生成画像にイメージマップを貼る

use GD::Graph::points;
my $graph = GD::Graph::points->new(400,300);

@data = (
	['1st', '2nd', '3rd'],
	[1, 2, 3],
);

my $image = $graph->plot(\@data) or die;
my @ret = $graph->get_hotspot(1);
for(my $i = 0; $i < @ret; $i++) &#123;
	print "<area shape=$ret[$i][0] Coords=$ret[$i][1],$ret[$i][4],$ret[$i][2],$ret[$i][3]>\n";
&#125;

■numerical X（x軸を数字として扱う）

1. x_min_value, x_max_value, x_tick_numberの３つを設定する


2. データ系列が３つ以上の値を含む


3. x軸のデータが全て数字

use GD::Graph::points;
my $graph = GD::Graph::points->new(400,300);

@data = (
	[1 ,1, 10],
	[1, 2, 3],
);

$graph->set(
	x_min_value => 0,
	x_max_value => 30,
	x_tick_number => 10,
);

my $image = $graph->plot(\@data) or die;

open(OUT, ">test.png") or die;
binmode OUT;
print OUT $image->png();
close(OUT);

■グラフ座標を画像のピクセル座標に変換

use GD::Graph::points;
my $graph = GD::Graph::points->new(400,300);

@data = (
	['1st', '2nd', '3rd'],
	[1, 2, 3],
);

my $image = $graph->plot(\@data) or die;
my $green = $image->colorAllocate(0, 255, 0);

my @p1 = $graph->val_to_pixel(1, 1);
my @p2 = $graph->val_to_pixel(3, 3);
$image->line(@p1, @p2, $green);

open(OUT, ">test.png") or die;
binmode OUT;
print OUT $image->png();
close(OUT);