Grant Edwards wrote: > I downloaded examples/contour_demo.py, and it doesn't run. > > I've searched both the user guide and the Wiki for "contour" > and got zero hits. > > http://matplotlib.sourceforge.net/matplotlib.pylab.html#-contour > appears to be a good reference if you already know how to use > contour(), but I could glean zero clues from it on how to > actually use contour(). For example, it doesn't explain what > the actual formats/types of the parameters. It explains what > the parameters do, but not what they _are_
Yes, unfortunately, much of the documentation was written by people who were very familiar with the Matlab interfaces that these functions are emulating. > For example one parameter is specied as "an array". No clue as > to how many dimensions or what the axis are. > > In another place it says "the X,Y parameters specify the (x,y) > coordinates of a surface". _How_ do they specify the surface? > Are they just equal length lists of x and y coordinates that > specify len(X) points. Or do they specify a len(X) x len(Y) > grid of points? > Why would my Z values be a 2D array? contour() only does contouring on gridded data. If you want to handle scattered datapoints, you will have to do some interpolation. http://www.scipy.org/Cookbook/Matplotlib/Gridding_irregularly_spaced_data So X, Y, and Z are all 2-D arrays laid out corresponding to the grid that you have sampled. I thought the contour_demo.py example was reasonably clear on this, but if you didn't get it to run, then I can see why you wouldn't have read it. Talking about this on matplotlib-users will probably get these problems fixed faster: https://lists.sourceforge.net/lists/listinfo/matplotlib-users -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco -- http://mail.python.org/mailman/listinfo/python-list
