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From |
Robert Duval <rduval@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
st: Re: Nice Margins programming challenge |

Date |
Sat, 4 Dec 2010 09:30:45 -0600 |

I think the answer can be found in here http://www.ats.ucla.edu/stat/stata/faq/ > Date: Fri, 3 Dec 2010 17:52:20 -0000 > From: Stephen Kay <stephen.kay@adelphigroup.com> > Subject: st: Nice Margins programming challenge > > This message is in MIME format. Since your mail reader does not understand > this format, some or all of this message may not be legible. > > - ------_=_NextPart_001_01CB9312.D55BA0FC > Content-Type: text/plain > > I'm using MFP command combined with xtgee to model a fractional logistic > model (dependent variable is a percent varying from 0 to 100% inclusive; > patients are clustered within a doctor). Command is: > > > > mfp,select(0.05): xtgee actimpair age bmi comorbidities > female > > > > The mfp command creates new tranformed age variables (lets call them age1 > and age2) based on the fractional polynomial terms it thinks best (and very > kindly gives the formula so they are easy to reproduce). > > > > I want to run Stata 11's Margins command to give predictions on the > dependent variable with 95% CI's across a large range of age values. > > > > It looks (to me at least) that I need to program a routine that for every > age value needing a prediction: > > (1) Generate the appropriate age1 and age2 values > > (2) Input these into the margins command using the "at" option > > (3) Store/append the resultant prediction plus SE, plus relevant age value > into a matrix holding all such results. > > (4) Compute the 95% CI's for the predictions and store them in the > relevant place in the matrix mentioned in (3). > > > > Final tasks after looping through all such ages populating the matrix > holding relevant results is to convert the matrix into data and graph from > it (this task at least I can do). > > > > I don't program often enough to accomplish the steps above quickly. > Hopefully some bright, public spirited spark can do it for me or show how it > can be done even more efficiently. To be honest I'm surprised I've not found > any previous posts or web files on this as I'd have thought quite a lot of > people would want to do this sort of thing. > > > > Any help much appreciated. > > > > Thanks, > > > > Steve > * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**Re: st: Re: Nice Margins programming challenge***From:*Steve Kay <arw.steve@googlemail.com>

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