Ryan May wrote: > Hi, > > In trying to add a symbol for an empty wind barb, I ran into problem. > Traditionally, a smaller, non-filled circle is used for low wind speeds > when doing a barb plot. I can draw the circle easily as a polygon, > using CirclePolygon from patches, but unfortunately, the fill color for > this polygon ends up being the same as the color of the flags on the > barbs. Therefore, as currently implemented, the only way to have > unfilled circles is to have unfilled flags. > > The only technical solution I can think of here is to have separate > collections for the circles and the polygons. Unfortunately, I have no > idea how to begin to do that within a class that inherits from > collections. Another option would be to somehow manually set the fill > colors on the circles after the collection is initialized. Anyone have > suggestions on how to make this work, or maybe a better technical solution.
Ryan, Yes, this would require some bigger changes. Instead of inheriting from PolyCollection, it would have to contain two collections, or a collection and a Line2D with markers. An alternative would be to override the PolyCollection.draw() method with a near-copy, but with logic added right before the renderer call to set the alpha (column 3) of the rgba array to zero for the circles. A better way might be to modify the original draw method to use self.get_facecolors() instead of self._facecolors; then one could override the get_facecolors method, which would require much less code. Eric > > Jeff, how aesthetically displeasing do you think it would be to have > small (possibly colored) circles to represent the low winds instead of > the traditional (somewhat larger) hollow circle? It would make it > impossible to do sky cover in a traditional surface map, but maybe > Z-ordering could be used to hack around it. > > Thoughts, > > Ryan > ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Matplotlib-devel mailing list Matplotlib-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
