This is with matplotlib 1.1.0, via the Pylab interface (I'm using a version supplied with PythonXY):
import pylab as p
import numpy as np
x = np.arange(10)
y = np.arange(10)-1
Saving the plot as an EPS or PDF produces an invalid file; when opening the PDF, Adobe Reader says "Path lacks initial MOVETO". PNG output looks fine.
Granted, negative values can't be plotted on a log scale, but creating a bad output file seems like a bug. As a workaround, I now filter my data for negative values before plotting.
Fixed, I think, by #684. Although, admittedly, that bug threw an exception
Just tried it with matplotlib 1.2.0 (new install via pip on Linux). When saving a PDF, I get a popup saying "Can only output finite numbers in PDF". When saving EPS, the save completes but the file can't be opened in any EPS viewer I tried.
Good catch. This seems to be specific to path collections, which is rare on a log plot, so we haven't caught it. Expect a fix shortly.
Fix #1799: path collections with NaNs in the path cause exceptions in…
… vector backends.
@andrewcollette: Would you mind testing the attached patch to confirm that it addresses your issue?