Maybe I understand what he means. How can a user override some value in a colormap? Lets say, in general user wants to inherit some ready made colormap but in addition wants to force certain colors to some data items. M.
Eric Firing wrote: > On 2014/03/02 1:02 AM, ChaoYue wrote: >> Dear Eric, >> >> This solved part of my problem. thanks a lot. >> I think I will revisit this issue when I have time (not promised). >> do you think this could be some feature desirable? > > I don't understand what feature you are referring to; evidently I don't > understand what the problem is, so I don't know what part remains unsolved. > > Eric > > >> >> Cheers, >> >> Chao >> >> >> On Sat, Mar 1, 2014 at 10:39 PM, Eric Firing [via matplotlib] <[hidden >> email] </user/SendEmail.jtp?type=node&node=42956&i=0>> wrote: >> >> On 2014/03/01 11:03 AM, ChaoYue wrote: >> > The most correct way might be to design a new colormap with white >> color >> > exactly in the middle, however this is very tedious, especially if I >> > want to try >> > different colormaps. so the alternative approach would be to set >> the values >> > falling in (-1,1) as being masked, so they will be the same as >> the axes >> > background color as you mentioned (in our case it's white). My >> question is, >> > how can I put this background color (which shows maksed data) in the >> > colorbar, >> > by avoiding design a new colormap? >> >> It's not the answer you want to hear, but I think the correct answer is >> that you should do this via the colormap, and not by masking the low >> values. It doesn't have to be painful. If, in contourf, you use a >> diverging colormap with white already in the middle >> (http://matplotlib.org/examples/color/colormaps_reference.html) and a >> norm with symmetric limits (vmin and vmax; you can let them be set >> automatically after you specify your symmetric set of contour >> boundaries >> appropriately) then it will be done for you. >> >> e.g., >> >> z = 10 * np.random.randn(20, 30) >> clevs = [-10, -5, -2, -1, 1, 2, 5, 10] >> cs = plt.contourf(z, levels=clevs, cmap=plt.get_cmap('PRGn'), >> extend='both') >> cbar = plt.colorbar(cs, spacing='uniform') >> >> Eric >> >> >> ------------------------------------------------------------------------------ > > > ------------------------------------------------------------------------------ > Flow-based real-time traffic analytics software. Cisco certified tool. > Monitor traffic, SLAs, QoS, Medianet, WAAS etc. with NetFlow Analyzer > Customize your own dashboards, set traffic alerts and generate reports. > Network behavioral analysis & security monitoring. All-in-one tool. > http://pubads.g.doubleclick.net/gampad/clk?id=126839071&iu=/4140/ostg.clktrk > _______________________________________________ > Matplotlib-users mailing list > Matplotlib-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-users > ------------------------------------------------------------------------------ Subversion Kills Productivity. Get off Subversion & Make the Move to Perforce. With Perforce, you get hassle-free workflows. Merge that actually works. Faster operations. Version large binaries. Built-in WAN optimization and the freedom to use Git, Perforce or both. Make the move to Perforce. http://pubads.g.doubleclick.net/gampad/clk?id=122218951&iu=/4140/ostg.clktrk _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
