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From |
Roger Harbord <Roger.Harbord@bristol.ac.uk> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
RE: st: how to make xi dummies inherit labels |

Date |
Thu, 03 Oct 2002 13:39:27 +0100 |

Hi John,

I've just installed the latest version of desmat available on SSC - Distribution-Date: 20011111. (I had the STB-61: dm73.3 version before.)However an -exp- option still doesn't exist:

. desmat: logistic siweekT2 age10yy2, exp

exp invalid

r(198);

. which desmat

c:\ado\stbplus\d\desmat.ado

*! version 3.0, 30Mar2001, John_Hendrickx@yahoo.com

And I'm not including any continuous covariates - only a single categorical one with 6 categories at present. -desmat- takes around 2 minutes even if I give an outcome variable that doesn't exist so that all it gives is an error message to that effect. (If given a non-existent covariate it complains straight away though.)

I suppose I could drop all those variables corresponding to questions that we're not using (data is results of a survey with a *long* questionnaire) but that would be some extra work to create and maintain a 'keep list' of variables I'm actually interested in.

Roger.

--On 03 October 2002 04:33 -0700 John Hendrickx <john_hendrickx@yahoo.com> wrote:

Hi Roger, -desmat- should add a few seconds to your calculations but two minutes is way too much. One explanation might be that a continuous variable wasn't specified as such, then -desmat- will create dummies for all 100+ categories and estimation will take a long time. Let me know if -desmat- really slows things down that much on a large dataset, maybe it would be worthwhile to create a lite version. As for exponential coefficients, use the -exp- option, desmat: logistic y x, exp will give the same results as xi: logistic y i.x -logistic- prints exponential coefficients but saves them as loglinear values. Good luck, John Hendrickx --- Roger Harbord <Roger.Harbord@bristol.ac.uk> wrote:What I was really after in the end was similar to the output of e.g. . xi: logistic y i.x . reformat, eform - but with the coefficients labelled using the value labels assigned to x. -desmat- does achieve this, but I had a couple of different problems when I tried -desmat-: 1) It takes over 2 minutes to run the first univariable logistic regression with -desmat- on my data , when -xi- is seemingly instant. May be connected to the fact that my dataset has 1100 variables (and 2400 observations). Much quicker subsequently though, even run on different variables. 2) I can't see how to get -desmat- to exponentiate the coefficients (to give odds ratios with logistic regression) when used as a command prefix: . desmat: logistic y i.x gives the same output as: . desmat: logit y i.x - and there's no -eform- option as there is with -outreg- and -reformat-. Also I think -reformat- or -outreg- give me more flexibility in deciding what I want in the output, so I don't need to do so much work on the output before I present it to my client, which is ultimately my aim. In conclusion i'll probably use Nick's 'canned solution' for transferring value labels to variable labels of dummies, in combination with -reformat- or -outreg-. But maybe it would be nice if there was an option for -xi- to tell it to inherit the labels in this way. Put that on the wish list for Stata 8... Roger. ---------------------------------------------------- Roger Harbord mailto:roger.harbord@bristol.ac.uk Department of Social Medicine, University of Bristol --On 03 October 2002 09:33 +0100 Nick Cox <n.j.cox@durham.ac.uk> wrote: > John Hendrickx > >> -desmat- will do this. Try -ssc describe desmat- > > I tried -desmat- after my posting. I couldn't > see that it did quite this. > > Example: > >----------------------------------------------------------------------> ------------------------------------- > log: C:\Stata7\desmat.log > log type: text > opened on: 3 Oct 2002, 09:30:21 > > . u auto > (1978 Automobile Data) > > . desmat : regress mpg foreign >----------------------------------------------------------------------> --------- > regress >----------------------------------------------------------------------> --------- > < snip > >----------------------------------------------------------------------> --------- > nr Effect Coeff > s.e. >----------------------------------------------------------------------> --------- > foreign > 1 Foreign 4.946** > 1.362 > 2 _cons 19.827** > 0.743 >----------------------------------------------------------------------> --------- > * p < .05 > ** p < .01 > > . d _x_1 > > storage display value > variable name type format label variable label >----------------------------------------------------------------------> --------- > _x_1 byte %8.0g foreign==1 > > > . tab foreign > > Car type | Freq. Percent Cum. > ------------+----------------------------------- > Domestic | 52 70.27 70.27 > Foreign | 22 29.73 100.00 > ------------+----------------------------------- > Total | 74 100.00 > > > That is, the variables created do not inherit value labels, > which I understood be what Roger wanted. > > Nick > n.j.cox@durham.ac.uk > > * > * For searches and help try: > * http://www.stata.com/support/faqs/res/findit.html > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/__________________________________________________ Do you Yahoo!? New DSL Internet Access from SBC & Yahoo! http://sbc.yahoo.com * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

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**Follow-Ups**:**RE: st: how to make xi dummies inherit labels***From:*John Hendrickx <john_hendrickx@yahoo.com>

**References**:**RE: st: how to make xi dummies inherit labels***From:*John Hendrickx <john_hendrickx@yahoo.com>

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