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RE: st: Suggestions for Second Edition of A Visual Guide to Stata Graphics


From   Fred Wolfe <fwolfe@arthritis-research.org>
To   statalist@hsphsun2.harvard.edu
Subject   RE: st: Suggestions for Second Edition of A Visual Guide to Stata Graphics
Date   Wed, 25 Jul 2007 13:26:13 -0500

I reply with great deference. Nick is the master of graph programs.

Perhaps I am wrong about the difficulty of this task.

Consider subjects who take one or more of 10 drugs at two time periods. I want to show the proportion of subjects taking each of the drugs at time 1 and time 2.

Drug 1 .................X................Y.........
Drug 2 ........................X..Y................
Drug 3 .. etc

If each drug was a category within "alldrugs" I could do this easily (over(alldrugs)). Because this is not the case, I have to overlay two graphs, perhaps fiddle with scaling, and maybe multiply variables, and so on. Have I missed something easy?

With respect to multiplying by 100, here's what I think I have to do. Either clone the variables of interest and multiply them by 100 or preserve, multiply, make the graph, restore. While this is a trivial task, it is also a nuisance.

The issue that I am raising is not that these tasks are not doable, but that it takes time to do them. Sometime a lot of time if one is not so facile or if one is working with multiple data sets. I would rather spend time analyzing data than fiddling with graph code. So, it would be nice if a graph book could address a series of simplifying issues like this. Stata, lets me type -or- after logit or clogit so that I don't have to take the time to do exponentiate separately. Stata doesn't yet allow similar ease of use extensions such as I have specified.

I hope I haven't missed something very easy. Michael Mitchell's book might add additional value by addressing a series of issues such as these and showing programs such as you have written to facilitate graphing.

Fred

At 12:34 PM 7/25/2007, you wrote:

Fred Wolfe replied to Michael Mitchell's request for suggestions
on a second edition of "A Visual Guide to Stata Graphics" with
several thoughts from his experience.

I have extracted two comments here, which should be of
interest beyond the book and before any second edition appears:

> For bar and dot graphs, orientation is almost exclusively to over()
> and by(). But I often have to make such graphs under circumstances
> where over groups are not mutually exclusive. For example, instead of
> having an over group for drugs that patients might take, I have
> situations where patients take more than one drug, making the over
> group option useless to me. So I would very much like to see an
> expanded section on handling overlapping groups - or non-grouped
> data. Too much group stuff for me, but perhaps not for others.

I am not clear what the difficulty here is at all. Please give
a specific example or more detail.

> Converting proportions to percentages is a frequent task. Maybe
> adding some lines of code to do simple tasks like this would be
> helpful.

Sorry, but what's the complication to be explained here?
Multiplication by 100?

Nick
n.j.cox@durham.ac.uk

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Fred Wolfe
National Data Bank for Rheumatic Diseases
Wichita, Kansas
Tel +1 316 263 2125
fwolfe@arthritis-research.org

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