plotting for cairo

I've been using cairo quite a bit recently. Inevitably, i've found myself wanting to do some graphs. Instead of doing an exhaustive search on the internet, I quickly decided that there was nothing suitable out there and I should do my plots manually for my application.

Some weeks (months?) on, I've noticed that this is not a sensible approach. I've spent a little more time on the internet looking for solutions, and had some helpful suggestions on email lists.

The primary candidate is:

• PLplot
• 
  

PLplot that provides an 'extcairo' driver. This driver will allow you to construct a cairo context in your app, pass it to PLplot, call PLplotting commands, and provide you with a nice graph plotted on your context.

An example is provided: http://plplot.sourcearchive.com/documentation/5.9.2/ext-cairo-test_8c-source.html

Up until now, I've been a heavy user of gnuplot. I'm currently interested in extending gnuplot to support this type of work-flow.