Re: [Matplotlib-users] Plotting curves filled with nonuniform color patch
http://matplotlib.1069221.n5.nabble.com/Plotting-curves-filled-with-nonuniform-color-patch-td25773.html Raising an old thread here, but does anyone know how to make this work with 'fill_between'? -- Try New Relic Now We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_may___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Plotting curves filled with nonuniform color patch
line 1486 of _backend_agg.cpp says /* TODO: Support clip paths */ So, it seems that, apparently, clipping with arbitrary path has not been implemented yet for gouraud shading (pcolormesh will be properly clipped if shading is not used). I hope Michael pick this up some time soon. Meanwhile, you may open a feature request ticket on this. Regards, -JJ On Wed, Dec 2, 2009 at 5:13 PM, Tony S Yu tsy...@gmail.com wrote: On Dec 2, 2009, at 3:53 PM, Tony S Yu wrote: Hi, I'm having hard time understanding some of the differences between functions used to plot color patches (not sure what to call them). I'm trying to fill a curve with a nonuniform color patch (like fill or fill_between but the color in the patch varies). I've attached code that almost does what I want; my question concerns the color patch (which is created by the call to plt.pcolor in the code below). I'd like to have nonuniform grid spacing in the color values, and also shading (i.e. interpolation of color between points). Here's what I understand: pcolor: allows nonuniform grid spacing, but it doesn't do shading. imshow: allows color shading, but requires uniform spacing pcolormesh: allows color interpolation and nonuniform grid spacing pcolormesh seems like the ideal candidate, but when I replace pcolor with pcolormesh (code commented out below pcolor call), the path doesn't get clipped by set_clip_path (but no errors are raised); in other words, the color shading fills the entire plot area. Is this a bug? Is there a way of making this plot work that I've overlooked? Thanks! -Tony Nevermind, I found NonUniformImage after some digging. The working code is attached below if anyone is interested. If anyone knows the answer, I'm still curious if the clipping behavior for pcolormesh is a bug. Thanks, -Tony # example code import numpy as np import matplotlib.pyplot as plt from matplotlib.image import NonUniformImage def nonuniform_imshow(x, y, C, **kwargs): Plot image with nonuniform pixel spacing. This function is a convenience method for calling image.NonUniformImage. ax = plt.gca() im = NonUniformImage(ax, **kwargs) im.set_data(x, y, C) ax.images.append(im) return im def plot_filled_curve(x, y, c): Plot curve filled with linear color gradient Parameters -- x, y : arrays points describing curve c : array color values underneath curve. Must match the lengths of `x` and `y`. # add end points so that fill extends to the x-axis x_closed = np.concatenate([x[:1], x, x[-1:]]) y_closed = np.concatenate([[0], y, [0]]) # fill between doesn't work here b/c it returns a PolyCollection, plus it # adds the lower half of the plot by adding a Rect with a border patch, = plt.fill(x_closed, y_closed, facecolor='none') im = nonuniform_imshow(x, [0, y.max()], np.vstack((c, c)), interpolation='bilinear', cmap=plt.cm.gray) im.set_clip_path(patch) if __name__ == '__main__': line = np.linspace(0, 1, 6) x = np.hstack((line, [1, 2])) y = np.hstack((line**2, [1, 1])) c = np.hstack((line, [0, 0])) plot_filled_curve(x, y, c) plt.show() -- Join us December 9, 2009 for the Red Hat Virtual Experience, a free event focused on virtualization and cloud computing. Attend in-depth sessions from your desk. Your couch. Anywhere. http://p.sf.net/sfu/redhat-sfdev2dev ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users -- Join us December 9, 2009 for the Red Hat Virtual Experience, a free event focused on virtualization and cloud computing. Attend in-depth sessions from your desk. Your couch. Anywhere. http://p.sf.net/sfu/redhat-sfdev2dev ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Plotting curves filled with nonuniform color patch
On Dec 3, 2009, at 3:58 PM, Jae-Joon Lee wrote: line 1486 of _backend_agg.cpp says /* TODO: Support clip paths */ So, it seems that, apparently, clipping with arbitrary path has not been implemented yet for gouraud shading (pcolormesh will be properly clipped if shading is not used). I hope Michael pick this up some time soon. Meanwhile, you may open a feature request ticket on this. Regards, -JJ Hey Jae-Joon, Thanks for digging into this. Feature request added. By the way, I was looking through the feature requests and noticed an open feature request (ID: 2112292) that was satisfied by the addition of spines in the last major release. Just an FYI, if someone with privileges wants to close the request. Thanks, -Tony -- Join us December 9, 2009 for the Red Hat Virtual Experience, a free event focused on virtualization and cloud computing. Attend in-depth sessions from your desk. Your couch. Anywhere. http://p.sf.net/sfu/redhat-sfdev2dev ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] Plotting curves filled with nonuniform color patch
On Dec 2, 2009, at 3:53 PM, Tony S Yu wrote: Hi, I'm having hard time understanding some of the differences between functions used to plot color patches (not sure what to call them). I'm trying to fill a curve with a nonuniform color patch (like fill or fill_between but the color in the patch varies). I've attached code that almost does what I want; my question concerns the color patch (which is created by the call to plt.pcolor in the code below). I'd like to have nonuniform grid spacing in the color values, and also shading (i.e. interpolation of color between points). Here's what I understand: pcolor: allows nonuniform grid spacing, but it doesn't do shading. imshow: allows color shading, but requires uniform spacing pcolormesh: allows color interpolation and nonuniform grid spacing pcolormesh seems like the ideal candidate, but when I replace pcolor with pcolormesh (code commented out below pcolor call), the path doesn't get clipped by set_clip_path (but no errors are raised); in other words, the color shading fills the entire plot area. Is this a bug? Is there a way of making this plot work that I've overlooked? Thanks! -Tony Nevermind, I found NonUniformImage after some digging. The working code is attached below if anyone is interested. If anyone knows the answer, I'm still curious if the clipping behavior for pcolormesh is a bug. Thanks, -Tony # example code import numpy as np import matplotlib.pyplot as plt from matplotlib.image import NonUniformImage def nonuniform_imshow(x, y, C, **kwargs): Plot image with nonuniform pixel spacing. This function is a convenience method for calling image.NonUniformImage. ax = plt.gca() im = NonUniformImage(ax, **kwargs) im.set_data(x, y, C) ax.images.append(im) return im def plot_filled_curve(x, y, c): Plot curve filled with linear color gradient Parameters -- x, y : arrays points describing curve c : array color values underneath curve. Must match the lengths of `x` and `y`. # add end points so that fill extends to the x-axis x_closed = np.concatenate([x[:1], x, x[-1:]]) y_closed = np.concatenate([[0], y, [0]]) # fill between doesn't work here b/c it returns a PolyCollection, plus it # adds the lower half of the plot by adding a Rect with a border patch, = plt.fill(x_closed, y_closed, facecolor='none') im = nonuniform_imshow(x, [0, y.max()], np.vstack((c, c)), interpolation='bilinear', cmap=plt.cm.gray) im.set_clip_path(patch) if __name__ == '__main__': line = np.linspace(0, 1, 6) x = np.hstack((line, [1, 2])) y = np.hstack((line**2, [1, 1])) c = np.hstack((line, [0, 0])) plot_filled_curve(x, y, c) plt.show() -- Join us December 9, 2009 for the Red Hat Virtual Experience, a free event focused on virtualization and cloud computing. Attend in-depth sessions from your desk. Your couch. Anywhere. http://p.sf.net/sfu/redhat-sfdev2dev ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
