Fabrice Silva wrote: > Le lundi 10 novembre 2008, wbrevis a écrit : >> I'm trying to plot one of my experimental data using scipy. Until now, >> all the work I did was using Matlab. For one of my normal data- >> visualization, I read ASCII or Binary files containing 4 columns: The >> first contains the x coordinate, the second the y one, and the third >> and fourth columns the velocity in the x and y directions (u and v), >> i.e. file= x y u v (ordered in columns). After reading the data in >> Matlab, I normally do: pcolor(x,y,sqrt(u.^2+v.^2)), in order to >> visualize in colors the velocity magnitude and then quiver(x,y,u,v) in >> order to see the associated vectors. I was reading the manual of >> scipy, including the plotting tools, but I am a bit lost (too much >> information to start). Can somebody help me with suggestions on how to >> read data using scipy and the best way to plot (pcolor+quiver)?. What >> about the function quiver3d of mlab, can be used for 2d representation >> of a flow field, together with surf (also mlab). >> >> Thank you in advance for your help and suggestions > > (Let's discuss the second point in the matplotlib list only.) > Can you try the following code : > > import matplotlib.pyplot as plt > import numpy as np > x, y= np.arange(0,2*np.pi,.2), np.arange(0,2*np.pi,.2) > X,Y = np.meshgrid(x,y) > U,V = np.cos(X), np.sin(Y) > plt.pcolor(X,Y,U**2+V**2) > plt.quiver(X,Y,U,V) > plt.show() > > If it is what you do want, then you then only need to import your own > data...
If you have a reasonably recent version of numpy, then you can use numpy.loadtxt; if the data file is as simple as it sounds, you can also use numpy.fromfile, even with an older numpy version. Or you can use matplotlib.mlab.load, from which numpy.loadtxt was derived, I believe. The docstrings for numpy.loadtxt and mlab.load are very thorough. Eric > ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
