Chris, The point is that contouring and gridding are two entirely separate operations--and this is true in general, not just for matplotlib. Contouring algorithms--at least all the ones I have looked at--work with data on a regular grid. There are many ways to map scattered data to a regular grid, so it makes sense to do this as a separate step, so you can choose a gridding method that works well for your particular type of data set. See http://www.scipy.org/Cookbook/Matplotlib/Gridding_irregularly_spaced_data
Now, if your data are already on a quadrilateral grid, as in the example you give, but your arrays have been flattened, then all you need to do is reshape your arrays so that they are 2-D, with the row number corresponding to Y (vertical on the plot) and the column index corresponding to X (horizontal). Filling in your example below to include 2 values of x, and assuming all three variables are numpy ndarrays, you could do something like this: x.shape = 2,3 y.shape = 2,3 z.shape = 2,3 contour(x.transpose(), y.transpose(), z.transpose()) The transposes are needed because your original z is arranged with y varying fastest. Eric Chris wrote: > I may be a bit thick, but I am having a heck of a time figuring out how to > use contour() properly. > Specifically, I do not see why the z dimension should be a 2d array. > It should only take a set of x,y,z > coordinates to produce a surface -- what is the extra dimension for? More > importantly, how do I take > "canonical" 3-d data, e.g.: > > x y z > 1 1 2.3 > 1 2 4.5 > 1 3 6.1 > 2 1 7.3 > . > . > . > > > and get it into the form that matplotlib demands? > > Thanks, > cf > > > ------------------------------------------------------------------------- > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services for > just about anything Open Source. > http://sourceforge.net/services/buy/index.php > _______________________________________________ > Matplotlib-users mailing list > Matplotlib-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-users ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
