Gaps between bars with pyplot.bar

Hello developers,

I'm seeing what appears to be a bug when plotting bars next to each
other without edges. In pdf output, you can see that there is a tiny
gap in between each bar, which renders as one pixel wide no matter how
far I zoom in. It's also visible in interactive or png output:

http://www.dumpt.com/img/viewer.php?file=mc0wf07aksrzqs1h8j5k.png

You can generate the above by running a slightly modified demo:

···

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#!/usr/bin/env python
# a stacked bar plot with errorbars
import numpy as np
import matplotlib.pyplot as plt

N = 5
menMeans = (20, 35, 30, 35, 27)
womenMeans = (25, 32, 34, 20, 25)
menStd = (2, 3, 4, 1, 2)
womenStd = (3, 5, 2, 3, 3)
ind = np.arange(N) # the x locations for the groups
width = 1.0 # CHANGED from 0.35 in the demo

# CHANGED: adding linewidth=0 to these calls
p1 = plt.bar(ind, menMeans, width, color='r', yerr=womenStd, linewidth=0)
p2 = plt.bar(ind, womenMeans, width, color='y', linewidth=0,
             bottom=menMeans, yerr=menStd)

plt.ylabel('Scores')
plt.title('Scores by group and gender')
plt.xticks(ind+width/2., ('G1', 'G2', 'G3', 'G4', 'G5') )
plt.yticks(np.arange(0,81,10))
plt.legend( (p1[0], p2[0]), ('Men', 'Women') )

plt.show()
-------------------------------------------

Any thoughts on why there's always a tiny gap between bars?

Thanks,
Jeff

Jeff Klukas
Physics Lecturer, University of Wisconsin -- Whitewater
Research Assistant, University of Wisconsin -- Madison
jeff.klukas@...830... | jeffyklukas@...831... | jeffklukas@...832...
http://hep.wisc.edu/~jklukas/