[Matplotlib-users] semilogy seems to only work once

Hi all,

I'm making multiple semilogy histograms, which for now are on separate
figures and not in subplots. Here's something patched together:
def makehistogram(data,strtitle, filename):
    fig = Figure()
    pylab.hold(False)
    pylab.semilogy(base=10)
    n, bins, patches = pylab.hist(data, 50, normed=1)
    pylab.setp(patches, 'facecolor', 'g', 'alpha', 0.75)
    pylab.xlabel('bins')
    pylab.ylabel('logP')
    pylab.title(strtitle)
    pylab.grid(True)
    pylab.savefig(filename,dpi=72)

The first call to makehistogram() saves the semilogy histogram I want, but
the subsequent calls create regular cartesian histograms. Am I missing
something?

Thanks