Thanks to Kit Baum, the -spineplot- package on SSC has been updated.
-spineplot- implements spine plots for two-way categorical data.
Stata 8.2 is required. Use -ssc- to install or update if interested.
In this version there are various changes, as in part previously
promised:
1. A -text()- option allows showing text at the centre of each tile.
This grows out of a suggestion on Statalist by Peter Jepsen, to whom
thanks for a good idea (which I initially resisted).
2. -aweights- are now supported.
3. Several detailed changes have been made to the help, which is
quite detailed (20 references).
The immediate trigger for writing this program, as has been previously
reported, was a Statalist posting by Matthias Schonlau. Further
off-list discussions with him and with Antony Unwin have underlined,
to my surprise, that the original definition of spine plots was much
more restrictive than is implemented here. This was in a paper by
Hummel (1996), which I cite in the help: so far no paper or electronic
version has come to my hand. However, offering a program that can draw a
wider variety of graphs than the original definition seems no great
vice to me, and I don't feel obliged to follow the original narrow
definition slavishly when a wider definition is very useful. However,
on some terminology what -spineplot- draws are not just spine plots
strict sense, but rather mosaic plots for two variables.
I did also look at the implementation of spine plots in R, which
at a wild guess is the software most frequently used for drawing them,
and it takes a similar stance.
I've kept the name -spineplot-, not least because the only obvious
alternative -mosaicplot- would be even more misleading, as the program
does not implement mosaic plots as usually understood for three or
more variables. I've no ambitions to extend the program that far.
I've yet to see a mosaic plot for so many variables that didn't
seem to cry out for a simpler alternative, ingenious though the idea
remains.
Nick
[email protected]
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