On 2015/05/21 5:50 AM, Matteo Niccoli wrote: > I posted a question on stackoverflow about creating with making my own > shading effect (I want to use horizontal gradient for the shading). > http://stackoverflow.com/questions/30310002/issue-creating-map-shading-in-matplotlib-imshow-by-setting-opacity-to-data-gradi > > > Unfortunately I cannot share the data because I am using it for a > manuscripts, but my notebook with full code listing and plots, here: > http://nbviewer.ipython.org/urls/dl.dropbox.com/s/2pfhla9rn66lsbv/surface_shading.ipynb/%3Fdl%3D0 > > The shading using gradient is implemented in two ways as suggested in the > answer. What I do not understand is why the last plot comes out with a > rainbow-like colors, when I did specify cubehelix as colormap. > > hsv = cl.rgb_to_hsv(img_array[:, :, :3]) > hsv[:, :, 2] = tdx_n > rgb = cl.hsv_to_rgb(hsv) > plt.imshow(rgb[4:-3,4:-3], cmap='cubehelix') > plt.show() > > > Am I doing something wrong or is this unexpected behavior; is there a > workaround?
Colormapping occurs only when you give imshow a 2-D array of numbers to be mapped; when you feed it a 3-D array of RGB values, it simply shows those colors. For colormapping to occur, it must be done on a 2-D array as a step leading up to the generation of your img_array. Eric > > Thanks > Matteo > ------------------------------------------------------------------------------ One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
