st: formatting bar graph by(groups)

["B. Timothy Walsh" <btw1@columbia.edu>]

I am attempting to build a graphical summary of 4 studies using bar graphs 
in Stata12. Two studies need 3 bars and 2 need 2 bars (corresponding to 
different numbers of Treatment cells in the various studies). I am very 
close to having what I want but have a minor annoying problem.
The command I am using includes the following elements, plus some 
formatting directions:
graph bar (asis) Baseline Change, stack over(Treatment) nofill ///
	by(study, cols(3) holes(4 6) title("Title")

The first 3 graphs—2 with 3 bars and 1 with 2—are fine. Each plot area 
is of the same width and the bars in the 2-bar graph are wider so they are 
nicely centered in the plot region. The problem is with the 4th graph: the 
2 bars are of the same width as in the 3-bar graphs, so they are over to 
the left and there's a space on the right side where a third bar would go, 
even though there is no third Treatment in that study.
I would like the bars in the 4th graph to be centered within the plot 
region, and of the same width as the other 2-treatment graph.
I hope this description is clear. Happy to supply any additional 
information. Thanks in advance!
Tim



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