Dr. Ruben Rao Thanks for your reply .But I don't know that how should I reparameterise the model.can you reply me in detail for reparameterization and taylor series for delta method . Thanks
--- On Tue, 7/13/10, Rubén Roa <r...@azti.es> wrote: From: Rubén Roa <r...@azti.es> Subject: RE: [R] ed50 To: "Dipa Hari" <harid...@yahoo.com>, r-help@r-project.org Date: Tuesday, July 13, 2010, 6:27 AM > -----Mensaje original----- > De: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] En nombre de Dipa Hari > Enviado el: lunes, 12 de julio de 2010 22:19 > Para: r-help@r-project.org > Asunto: [R] ed50 > > I am using semiparametric Model > library(mgcv) > sm1=gam(y~x1+s(x2),family=binomial, f) > > How should I find out standard error for ed50 for the above > model ED50 =( -sm1$coef[1]-f(x2)) / sm1$coef [2] > > f(x2) is estimated value for non parametric term. > > Thanks Two ways, 1) Re-parameterise the model so that ed50 is an explicit parameter in the model, or 2) Taylor series (aka Delta method) using the standard errors of coef[1], coef[2] and their correlation. HTH ____________________________________________________________________________________ Dr. Rubén Roa-Ureta AZTI - Tecnalia / Marine Research Unit Txatxarramendi Ugartea z/g 48395 Sukarrieta (Bizkaia) SPAIN [[alternative HTML version deleted]]
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