RE: st: Arrow diagram connecting before and after categories

["David Radwin" <dradwin@mprinc.com>]

Stata 12 does include a facility for drawing path models as part of its
structural equation modeling capability. I'm not sure if it will solve
your problem or not. See
http://www.stata.com/stata12/structural-equation-modeling for an example.

David
--
David Radwin
Senior Research Associate
MPR Associates, Inc.
2150 Shattuck Ave., Suite 800
Berkeley, CA 94704
Phone: 510-849-4942
Fax: 510-849-0794

www.mprinc.com


> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-
> statalist@hsphsun2.harvard.edu] On Behalf Of Nick Cox
> Sent: Tuesday, August 07, 2012 2:16 AM
> To: statalist@hsphsun2.harvard.edu
> Subject: Re: st: Arrow diagram connecting before and after categories
> 
> -linkplot- is from SSC. Please note the request to explain where
> user-written programs you refer to come from. I see no problem in
> using one y variable with different labels, as marker labels exist for
> that purpose.
> 
> Multiple arrows from one node (vertex) to several others are no
> problem so long as each edge or link is represented by an observation.
> Thus if a preliminary diagnosis is refined to a final diagnosis for
> various persons
> 
> "A"   "beginner problem"   "didn't read manual"
> "A"   "beginner problem"  "model wrong for data"
> "A"   "beginner problem"  "needs new code"
> "B"   "beginner problem"  "syntax error"
> "C"   "beginner problem"  "data wrong for model"
> "C"   "beginner problem"  "version conflict"
> 
> that is unproblematic so long as the data structure is as above.
> 
> Your problem thus sounds easy but see for details
> 
> Cox, N.J. 2009. Paired, parallel, or profile plots for changes,
> correlations, and other comparisons.
> Stata Journal 9(4): 621-639
> 
> Abstract.  Paired, parallel, or profile plots showing the values of
> two variables may be constructed readily using a combination of graph
> twoway commands. This column explores the principles and practice of
> such plot-making, considering both wide and long (panel or
> longitudinal) data structures in which such data may appear.
> Applications include analysis of change over time or space and indeed
> any kind of correlation or comparison between variables. Such plots
> may be extended to show numeric values and associated name
> information.
> 
> That said, it is not clear how effective such graphs will be as
> numerous identical links are shown by the same arrow and Stata doesn't
> readily support lines proportional in thickness to some other
> variable. Depending on how many diagnoses you have I am led to suggest
> -tabplot- (SSC) as an alternative.
> 
> Nick
> 
> On Mon, Aug 6, 2012 at 11:56 PM, Mollie Hogan <hogan@post.harvard.edu>
> wrote:
> 
> > I am hoping to get some help with a graphing issue. I'm trying to
> > create what I can best describe as a before/after arrow diagram
> > showing reclassification of categorical variables.
> >
> > I have a dataset where each observation is one death. Each death goes
> > through a review process, and I have one variable showing the cause of
> > death before the review process, and another variable showing the
> > cause of death after the review process. I want a diagram that has, on
> > the left side, the list of causes BEFORE the review and then on the
> > right side, the list of causes AFTER the review. I want each case
> > represented by a line connecting the appropriate before and after
> > causes. Pretty straightforward, right? The hitch is that the "before"
> > categories are in broad groupings and the "after" causes are more
> > specific than that. So the list of causes before and after is not the
> > same.
> >
> > I have tried several things: linkplot got me the closest, but I cannot
> > label the "before" and "after" categories with different labels (since
> > it's just the one yvar). I have started trying to overlay many line
> > graphs, and then add text manually, but I have quite a lot of
> > categories and thought I would ask and see if anyone has any other
> > thoughts about a good approach or user-written command that might do
> > the trick.
> >
> > I am running Stata 11.2 on a Mac, but can access 12.1 on Windows if
> > the solution lies there!

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