(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...
···
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
--
Fabricio
Fabrice Silva wrote:
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
···
Le lundi 10 novembre 2008, wbrevis a écrit :