How to create grid / heatmap images in Ruby?

Question

Looking for a way to visualize data by generating simple graphics in Ruby.

Is there a gem that allows you to crete simple images, such as a checkerboard?

It should be:

• Easy to use
• Ruby 1.9.3
• Not require Rails
• Saves image in at least one common format such as jpeg, gif or png

EDIT: After doing more research, I found that the name of the chart is grid or heatmap. Found this RubyVis library.

Answer 1

Chris Lowis gave a talk at Ruby Manor conference in London in December 2009 on doing visualizations in Ruby. Perhaps you might be interested in his slides[pdf] and examples?

Answer 2

RMagick is well-documented and supports several common file formats. It's an interface to ImageMagick, so you need to have that installed to use it.