samchristy / piechart

A simple class for drawing Pie Charts with ImageMagick or GD in PHP.

PieChart

A reasonably efficient* class for drawing pie charts with ImageMagick or GD in PHP. Intended as a learning exercise for using the NetBeans IDE and the Xdebug profiler and debugger. The code is available under the GNU GPL v3.0, so feel free to use it with attribution. I recommend using the Imagick version, PieChartImagick over the GD version, PieChartGD.

Demonstration

Below is the code required to generate a pie chart and echo it to the client's browser. The example uses the method outputPNG() to tell the browser to render the image. Alternatively, the function forceDownloadPNG() can be used to instruct the browser to bring up the save dialog.

Documentation

View the documentation (generated with ApiGen).

Installation

Use Composer!

Example Usage

<?php
require 'vendor/autoload.php';  // Composer's autoloader.
use SamChristy\PieChart\PieChartGD;

$chart = new PieChartGD(600, 375);

$chart->setTitle('Browser Usage Statistics (January - April)');
// Method chaining coming soon!
$chart->addSlice('Google Chrome',   27, '#4A7EBB');
$chart->addSlice('Mozilla Firefox', 23, '#DA8137');
$chart->addSlice('Apple Safari',    11, '#9BBB59');
$chart->addSlice('Opera',            3, '#BE4B48');
$chart->addSlice('Other',            5, '#7D60A0');

$chart->draw();
$chart->outputPNG();

Output

*This example took 150ms to execute on my laptop (i3-350M @ 2.27 GHz).

© Sam Christy 2013

piechart's Issues

Add transparency feature

Hey, I have used this library in one of my projects and wondered if you were thinking of adding transparency to the features?

I have added it to my fork, in a really nasty and basic way; if I get time I shall work on making it an alpha transparency so it doesn't end up with nasty edges when in png mode.

Slice arcs that are larger than 180 degrees will overlap previously drawn slices

If a piechart has a large slice that takes up more than 50% of the piechart the filling of the arc shape might overlap previous slices.

It can be solved by checking if the to be drawn slice has a start and end difference > 180 in the _drawSlice function. If so I divide the slice in 2 parts and draw those using the same _drawSlice function.

Some complete graphics and some not

I am making a loop in several items to get the graph of each one

` $chart = new PieChartGD(450, 350);

    $chart->setTitle($questao->questaoEnunciado);

    foreach ($questao->relatorio as $x) {
        $chart->addSlice($x->resposta,$x->total,colorHEX($x->resposta));
    }
    
    $chart->draw();
    $chart->savePNG(FCPATH.'/graficos/'.$questao->questaoID.'.png');`