>From: "Liaw, Andy" >To: "'nuvo nuvo'" ,[EMAIL PROTECTED] >Subject: RE: [R] Better way to find function >Date: Wed, 21 Jan 2004 09:10:06 -0500 > >For #1, could you clarify what you mean by `function', an R function, or a
>regression function? I mean to choose a functional form automatically, e.g. 1/( a+exp[b+cx]), a+bx, ... [ I saw some of the commercial software can do it ]. >For #2, there are several packages on CRAN (and in the R distribution >itself) that fit regression splines, if that's what you meant by `piecewise >regression'. For logistic regression, you can either use the bs() term in >glm(), or gam() in the `mgcv' package. I don't want to use Spline, because I need the functional form and also parameters. Moreover I have 3 independent variables, not only one. I want to do only 2 piecewise regression by using the logistic function i.e. c/( 1+exp[a+bx]). Then it will be difficult where to put the knot and also it may not be continuous at the knot. > >HTH, >Andy > > > From: nuvo nuvo > > > > To whom it may concern, > > > > 1. I would like to know if there is a command in R to choose > > a function for > > a given dataset. I am facing a difficult question about how > > to fit the data > > [ please attachment ] > > > > 2. Are there any function that will allow users to do the piecewise > > regression? > > > > If not, is it going to be provide in the new updated version? > > What I am > > using is the piecewise logistic regression, but it doesn't > > have a continuous > > function though. I hope that R would have a specific command > > to do the > > piecewise (non)linear regression. > > > > I would apprecaite your suggestion. > > > > Sincerely yours, > > > > Nhum > > > > _________________________________________________________________ > > Rethink your business approach for the new year with the > > helpful tips here. > > > > ______________________________________________ > > [EMAIL PROTECTED] mailing list > > https://www.stat.math.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! > > http://www.R-project.org/posting-guide.html > > > > > > >--------------------------------------------------------------------- --------- >Notice: This e-mail message, together with any attachments, contains >information of Merck & Co., Inc. (One Merck Drive, Whitehouse Station, New >Jersey, USA 08889), and/or its affiliates (which may be known outside the >United States as Merck Frosst, Merck Sharp & Dohme or MSD and in Japan, as >Banyu) that may be confidential, proprietary copyrighted and/or legally >privileged. It is intended solely for the use of the individual or entity >named on this message. If you are not the intended recipient, and have >received this message in error, please notify us immediately by reply e-mail >and then delete it from your system. >--------------------------------------------------------------------- --------- _________________________________________________________________ [1]Learn how to choose, serve, and enjoy wine at Wine @ MSN. References 1. http://g.msn.com/8HMBENUS/2749??PS= ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
