Steve, I guess I should have highlighted the difference. For my application I need the circle radii to be given in data coordinates. For the curious, I'm plotting something very similar to Dorling Cartograms. I did look in the source of "scatter" for clues, but it uses a 20 sided polygon to approximate a circle. It looks like scatter_classic did what I wanted, but that's been removed :-(.
- Andrew Stephen George wrote: > It *seems* like it already does what you are trying to do?, maybe I'm > missing something in my understanding. > > Steve > > > > Andrew McLean wrote: >> I'm a new user of matplotlib (athough I have been using both Matlab and >> Python for years). >> >> I have an application where I need to display data as a set of filled >> circles. The centre and the radius of the circles are both specified in >> data coordinates. The data points have an additional scalar attribute, >> which is displayed using a pseudo-colour mapping. >> >> I've hacked something together where the circles are approximated by >> polygons using either the axis fill method or the pylab fill function. I >> select the colour by calling the get_rgba method of a ScalarMappable >> object. In the following code snippet c is a tuple containg the x and y >> coords of the centre of the circle, the radius, and a scalar "value" >> >> theta = arange(numSegs+1) * 2.0 * math.pi / numSegs >> cos_theta = cos(theta) >> sin_theta = sin(theta) >> for c in cart: >> x = c[1] + c[3] * cos_theta >> y = c[2] + c[3] * sin_theta >> v = c[4] >> fill(x, y, facecolor=mapper.to_rgba(v), linewidth=0.5) >> >> It all works. However, I saw in the API documentation (and the source) >> that there is a Circle object in patch. I was hoping that using this >> rather than polygons would give better quality output and possibly >> smaller files. Now I can instantiate it >> >> circle = Circle((x,y), c[3], facecolor=cmapper.to_rgba(v)) >> >> but can't work out what to do with it! I've tried >> >> ax.add_patch( circle ) >> >> and also >> >> trans = blend_xy_sep_transform( ax.transAxes, ax.transData ) >> circle.set_transform( trans ) >> ax.add_patch( circle ) >> >> Neither work. Any ideas? >> >> Regards, >> >> Andrew >> >> ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
