Well, it did help at least to understand a bit more, although I still fail to do it.
The code in the file axes3d.py says that keyword arguments passed to scatter3D are passed on to matplotlib.scatter, so I would expect the following two figures to work similarly in terms of color: import matplotlib as mpl import numpy as np from mpl_toolkits.mplot3d import Axes3D f1=mpl.figure() mpl.scatter(X,Z,c=np.abs(Z/3.0)) # My Z is in [-3.0, 3.0] f2=mpl.figure() ax=Axes3D(f2) ax.scatter3D(X,Y,Z,c=abs(Z/3.0)) mpl.show() It happens that f1 shows what I expect, a scatter in 2D with the colors of markers mapped to a colormap (I believe its jet). For f2, the markers appear as white filled circles. I am using python 2.6.6 in Debian squeeze (amd64) with python-matplotlib version 0.99.3-1 Thanks for any help or comment. On Thu, Oct 14, 2010 at 1:59 AM, Benjamin Root <ben.r...@ou.edu> wrote: > On Wed, Oct 13, 2010 at 5:46 PM, Pedro M. Ferreira <pmffferre...@gmail.com> > wrote: >> >> Hi All, >> >> I have been trying to make a 3D scatter plot using mplot3d and I would >> like the markers to have their colour according to the Z value. >> >From what I understood in the tutorial and API I have to use the cmap >> and norm kwargs, but all my attempts failed. >> >> I am trying to do it like this: >> ax.scatter(x,y,z,s=10,marker='o',c=????,cmap=????,norm=????) >> >> However I am not sure what to pass to c, cmap and norm. >> >> Any help ? >> Thanks. >> >> Cheers, >> Pedro >> > > It has been a while since I played around with this, and I am working > completely off my memory right now, but here goes... > > If I remember correctly, the 'c' values can be an array that is parallel to > the x, y, z arrays and specifies the color in one of two ways. First, the > array could have a list of color specs (e.g., 'k', 'r', 'b'). Second, the > array could contain values that would be passed to the colormap to retrieve > the colorspec according to where the value lies on the scale of 0 to 1. > > If you want to use just simple colors, go ahead and just make a list of > characters like so: > > ['k', 'r', 'g', 'g', 'b', 'k'] > > based on whatever the values are in z (I recommend using numpy's where() > function for this. > > I am not 100% sure if you need the following or if mpl will just autoscale > for you. So you might want to first just try out using the 'c' keyword. > > If you want to use the colormap, then the values passed into c either has to > be the normalized values of z > > c = (z - z.min()) / (z.max()-z.min()) > > or you can use one of the Normalize classes in matplotlib.color (assuming > you have imported matplotlib.pyplot as plt): > > norm = plt.Normalize(z.min(), z.max()) > > or whatever minimum and/or maximum values you wish. > > I believe you can use the default colormap by not specifying anything at all > for cmap, but I could be wrong here. You can also specify any colormap by > their name like 'spring', 'jet', 'bone' and so on. > > I hope that helps. > Ben Root > > ------------------------------------------------------------------------------ Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 & L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today. http://p.sf.net/sfu/beautyoftheweb _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
