There is a new project derived from wxMathPlot: it is gpPanel. It adds some new features like bar charts. Some bug fixes has been included in release 0.1.2 of wxMathPlot, but the new layers (for the moment) remains in a separate project, but I'm glad to it announce here. I believe that the codes can merge in the future, but I prefer to delay this, to ensure a more homogeneous interface.
Thanks to the author fot its work and useful new features.