Ada: plotting 2d graphs

Question

it would be interesting to be able to plot a 2D graph within an Ada code rather than having to save values say to file and use an external drawing software afterwards. A search

Answer 1

MathGL is cross-platform GPL plotting library. It have C interface, so you can use it from yours code too. Also it can create a window with graphics -- i.e. you don't need to study/use other widget libraries in simplest case.

Answer 2

PLplot is a cross-platform package for creating scientific plots. It has a well-documented Ada binding. For reference, this gallery illustrates a variety of plots. Click a thumbnail to view a full-size image. Click either Ada tab (standard or traditional) to see the corresponding source code.

Answer 3

It depends on exactly what you want to do. For graphing node-based diagrams, the first thing I'd look into using is Graphviz. It has its own special graphing language it uses, but I'm all about using Domain Specific Languages when appropriate. Ada has great interoperability, so using DSLs with it can really make it powerful.

An example I found is AdaDesigner, which generates Graphviz DOT files to help visualze the structure of Ada code.

The one time in the past I had to do simple plotting, it was for a web app. I ended up dynamically generating SVG pages on the server side (even though it was poorly supported then). Support is better now, so I'd definitely use it again today.

If working directly on a Windows PC display appeals more to you, there are several options for GUI bindings, all of which should support drawing lines and points on a canvas. In addtion to GTK (which is both powerful and portable), there are a few Win32 API's floating around. I think one comes with Gnat. Another you might not be aware of is GWindows. It is part of GNAVI, which aims to be sort of an OpenSource alternative to Delphi. It isn't the most active of projects, but is (reportedly) quite useable, and is still being worked on and used. Here are some screenshots of it being used for plotting.
_{(source: gnavi.org)}

Answer 4

I'd give a try to GTKAda. I'm not completely sure this subsystem would allow you to do 2D graphs as I've never used it for that purpose, but it can be done with GTK+ (C/C++).

There is also a guide on GTKAda and a reference manual, some documentation on the GTK toolkit itself may also come handy.