ruby-gdchart

= Ruby/GDChart 1.0.0

This is an extension library designed by Arjen Laarhoven, Takehiro Yonekura, and most recently Daniel Wislocki, to wrap the GDChart C library written by Bruce Verderaime (http://www.fred.net/brv/chart/). Arjen Laarhoven wrote the original version back in 2000, and Takehiro Yonekura updated it in 2002. Compared to them, I've done relatively little other than to turn the package into a gem, add a few missing (but extremely important) constant definitions, and upgrade the GDChart library itself to 0.11.5dev. (Note: The C library that this gem wraps is included, but requires the installation of gd-2.0.28 or higher.)

== A Brief Example

The following example creates a simple 200x200 PNG chart and writes it to STDOUT:

require 'rubygems' require_gem 'ruby-gdchart'

GDChart.title = "A Chart" GDChart.xtitle = "X-axis" GDChart.ytitle = "Y-axis" data = [1, 2, 3, 4, 5, 6]

the wrong number of labels cause Ruby/GDChart to segfault!

labels = ["label 1", "label 2", "label 3", "label 4", "label 5", "label 6"] numpoints = 6 numsets = 1 xsize = 200 ysize = 200 GDChart.out_graph(xsize, ysize, $stdout, GDChart::LINE, numpoints, labels, numsets, data)

== Caveats

This library works, but there has been practically no testing. Documentation is also extremely sparse (this goes for the original C library as well), which I hope to rectify in the future. It's recommended that you take a look at Bruce Verderaime's page (http://www.fred.net/brv/chart/) to get a good sense of how the library works, since the extension has an almost 1-1 mapping with the C library.

== License

This extension is distributed under the same terms as Ruby (see http://www.ruby-lang.org/en/LICENSE.txt. The included gd-1.8.3 (needed by GDCHART) and gdchart0.11.5dev libraries have their own license terms.