On 06/13/2012 07:31 AM, jonasr wrote: > > Hi, > > im actually trying to make a countour plot Z=f(X,Y) from two variables X,Y . > My Problem is that i have to use a logarithmic scale for the Z values. > If i plot the data with the logarithmic scale it gets pretty ugly, because i > have a lot of values which are zero, > which means on the log scale the value goes to -inf. > Here is an example what i mean > > http://www.imagebanana.com/view/qh1khpxp/example.png > > I acutally have no idea how to make the plot look better, > maybe somebody has an idea ?
Use np.ma.masked_less to mask out values below some threshold before taking the log. e.g., import matplotlib.pyplot as plt import numpy as np x = np.arange(0, 1, 0.01) y = np.arange(0, 8, 0.05) X, Y = np.meshgrid(x, y) Z = 10 ** (-5 + 11 * X * np.sin(Y)) Z = np.ma.masked_less(Z, 1e-4) Zlog = np.ma.log10(Z) CS = plt.contourf(X, Y, Zlog, levels=np.arange(-3, 5.01, 1.0), extend='both') plt.colorbar() Eric > > thank you ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
