Greetings, folks. I am a Matplotlib novice.

I'm trying to produce a 2D plot of data points where the X-axis

represents a sequence of named events. A grid and xticklabels have

been enabled for clarity.

For a sample size of 11, all the points fall on the grid. For 12,

they do not. Beyond that seems to be on a case-by-case basis.

I'm sure I must be abusing the relationship between ticks and data,

but the proper solution eludes me.

Below is a distilled version of the script. This was run on

Matplotlib 0.65 and Numarray 1.1.1. We have similar problems with

Matplotlib 0.80 and Numeric 23.8. What am I doing wrong?

--Rick Kwan

---- novice script starts here ----

from pylab import *

# top = 11 # 11 produces point on grid

top = 12 # 12 produces skewed data points

iter = [i for i in range(top)]

ax = subplot(111)

plot(iter, iter, 'gd-')

grid(True)

ax.xaxis.set_major_locator(LinearLocator(top))

xlabs = ax.set_xticklabels(['evt%d'%i for i in range(top)])

show()