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From |
John Hendrickx <john_hendrickx@yahoo.com> |

To |
statalist@hsphsun2.harvard.edu |

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

Date |
Thu, 3 Oct 2002 06:37:04 -0700 (PDT) |

Hello once again, I've forgoten my own command syntax, it should be: desmat: logistic siweekT2 age10yy2, desrep(exp) There's an example on this in the help file although I suppose you do have to know where to find it. As for the speed problems, I'm mystified. I just tried a dataset with 20375 cases and 238 variables and that was no problem (although I did have to increase matsize and memory). You might want to try desmat as a command, see if that sheds some light on the problem: desmat age10yy2 logistic siweekT2 _x_* desrep, exp drop _x_* Of course, if you already have an alternative solution then there's no need to waste any more time, but I'm curious about this speed problem with desmat. Pretty strange. John Hendrickx --- Roger Harbord <Roger.Harbord@bristol.ac.uk> wrote: > 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 > >> > > >> > > > ---------------------------------------------------------------------- > === message truncated === __________________________________________________ Do you Yahoo!? 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**Follow-Ups**:**RE: st: how to make xi dummies inherit labels***From:*Roger Harbord <Roger.Harbord@bristol.ac.uk>

**References**:**RE: st: how to make xi dummies inherit labels***From:*Roger Harbord <Roger.Harbord@bristol.ac.uk>

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