Winpython is a project which brings together a number of scientific python programs and modules. For me such programs are always going to struggling to become a complete alternative to Matlab (while I have access to a matlab license at least…).
I’ve not used it in anger, but this project does look pretty good. It pulls together a whole load of scientific programming modules/features for python and bundles them all together. It’s actively developed, too.
Plotting is taken care of by matplotlib. I really like the appearance of the figures it produces, such this one from the gallery on the webpage:
One very nice touch is the Spyder user interface: it has an ipython shell which is set up for scientific programming, and a variable explorer from which I can select and plot data. It just works.
Winpython Spyder interface showing Ipython command line, script editor and easy to use documentation viewer.
The Ipython command line interface seems to work well, and I had no problem creating arrays and making basic plots.
Of course there may be some ‘killer features’ which you just have to use matlab for, but Winpython seems like a very solid, capable alternative. And let’s not forget this one comes for free!