I would like to do a logistic multiple regression on a binary variate, with what Genstat calls an offset, ie a regression variable with the coefficient constrained=1. I'm far from home and have Splus but not R here, but any information from either source would be very welcome. I'd hate to have to go back to using Genstat . . . Thanks, Ted. --------------- Dr E.A. (Ted) Catchpole School of Maths & Stats University College, UNSW Institute of Maths & Stats Australian Defence Force Academy University of Kent at Canterbury e-catchpole at adfa.edu.au Canterbury, CT2 7NF, England http://www.ma.adfa.edu.au/~eac E.A.Catchpole at ukc.ac.uk -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
offset
3 messages · E.A.Catchpole, Brian Ripley, Marlene Mueller
On Wed, 29 Nov 2000, E.A.Catchpole wrote:
I would like to do a logistic multiple regression on a binary variate, with what Genstat calls an offset, ie a regression variable with the coefficient constrained=1. I'm far from home and have Splus but not R here, but any information from either source would be very welcome. I'd hate to have to go back to using Genstat . . .
Use offset() in the formula to glm. In R only, you can also specify offset as a parameter to glm: there are examples on ?glm in R (I know, I added them).
Thanks, Ted. --------------- Dr E.A. (Ted) Catchpole School of Maths & Stats University College, UNSW Institute of Maths & Stats Australian Defence Force Academy University of Kent at Canterbury e-catchpole at adfa.edu.au Canterbury, CT2 7NF, England http://www.ma.adfa.edu.au/~eac E.A.Catchpole at ukc.ac.uk -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
"E.A.Catchpole" wrote:
I would like to do a logistic multiple regression on a binary variate, with what Genstat calls an offset, ie a regression variable with the coefficient constrained=1. I'm far from home and have Splus but not R here, but any information from either source would be very welcome. I'd hate to have to go back to using Genstat . . .
Offsets can be given in the same way in R, ie: use glm with binomial family and logit link; do not include your constrained variable into the formula but use it as the optional offset parameter. Alternatively (and I suppose, that is the way you have to go in Splus), you can use offset() in the formula for glm. Hope that helps, Marlene -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._