[Matplotlib-users] custom color cycle from cmap
Hi, I'm trying to plot a set of lines, 12 to be exact, and the default color cycle only supports 8 or 9 distinct colors. That said, I looked up the color maps and segmented it using 12 constant intervals with the hope of getting 12 distinct colors. The problem I'm running in to is that some of the line colors I get are too close to each other. This is because come shades in the colormap have a broader spectrum than others. Here is my code to set my custom default color cycle: import matplotlib as mpl cmap = mpl.cm.get_cmap(name='spectral') #I gues we can also use hsv or gist_rainbow nColors = 12 #number of colors incr = 0.9 / nColors self.mycolors = [] for i in np.arange(0,0.9,incr): self.mycolors.append(cmap(i)) mpl.axes.set_default_color_cycle(self.mycolors) Can anyone suggest a cleaner method? Or is there perhaps an existing class to provide distinct color lines? Thanks, Krishna -- View this message in context: http://old.nabble.com/custom-color-cycle-from-cmap-tp28177653p28177653.html Sent from the matplotlib - users mailing list archive at Nabble.com. -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] custom color cycle from cmap
On Apr 8, 2010, at 8:13 AM, KrishnaPribadi wrote: Hi, I'm trying to plot a set of lines, 12 to be exact, and the default color cycle only supports 8 or 9 distinct colors. That said, I looked up the color maps and segmented it using 12 constant intervals with the hope of getting 12 distinct colors. The problem I'm running in to is that some of the line colors I get are too close to each other. This is because come shades in the colormap have a broader spectrum than others. Here is my code to set my custom default color cycle: import matplotlib as mpl cmap = mpl.cm.get_cmap(name='spectral') #I gues we can also use hsv or gist_rainbow nColors = 12 #number of colors incr = 0.9 / nColors self.mycolors = [] for i in np.arange(0,0.9,incr): self.mycolors.append(cmap(i)) you could replace the loop with a list comprehension: mycolors = [cmap(i) for i in np.arange(0,0.9,incr)] Also, arange may not be a great fit for this task; maybe linspace would work better: mycolors = [cmap(i) for i in np.linspace(0, 0.9, nColors)] This allows you to eliminate the assignment of `incr`. Note: the above colormap is different than that created by arange because linspace includes the endpoint, while arange doesn't. Hope that helps, -Tony mpl.axes.set_default_color_cycle(self.mycolors) Can anyone suggest a cleaner method? Or is there perhaps an existing class to provide distinct color lines? Thanks, Krishna -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] custom color cycle from cmap
Thanks Tony. That helps clean up the code. Now that I think about it more, I actaually had 2 questions. The first you answered well. The second question relates to my problem when using this method in that it produces line colors where some colors are too similar. In other words, there isn't enough of a stark differnece in color between the lines. Can someone suggest a different method (or something that may already be built in) of coming up with 12 or more line colors (more than the built in 8) that are stark? (I know I'm nit-picking and can probably just pick out my own colors but it's an interesting excersize). -- View this message in context: http://old.nabble.com/custom-color-cycle-from-cmap-tp28177653p28180731.html Sent from the matplotlib - users mailing list archive at Nabble.com. -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
