In order ot see if any of these syntaxes work or not, I made the QQ plot. Attached files are showing the QQ plots made when log was inside the model formulation and outside teh model formulation. You can see that when transformation were done outside, then I have a general better QQ plot (straight line fitted to the data).
Saeed Philipp Pagel-5 wrote: > > On Tue, Feb 24, 2009 at 02:46:07AM -0800, Saeed Ahmadi wrote: >> I have a data set (weight) that does not follow the Gaussian (Normal) >> distribution. However, I have to transform the data before applying the >> Gaussian distribution. I used this syntax and used log(weight) as: >> posJy.model<-glm(log(weight) ~ factor(pos), >> family=gaussian(link='identity'), subset=Soil=="Jy"). This syntax COULD >> NOT >> transform the data. But if I transform the data before applying the >> model, >> then it works. The syntax is: >> >> weight<-log(weight) >> posJy.model<-glm(weight ~ factor(pos), family=gaussian(link='identity'), >> subset=Soil=="Jy") > > That should work. Maybe you should tell us what happened or why you > think it didn't work. Error messages? Unexpected results? > > cu > Philipp > > -- > Dr. Philipp Pagel > Lehrstuhl für Genomorientierte Bioinformatik > Technische Universität München > Wissenschaftszentrum Weihenstephan > 85350 Freising, Germany > http://mips.gsf.de/staff/pagel > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > > http://www.nabble.com/file/p22180394/qq%2Bplot%2Bwith%2Bthe%2Blog%2Btransformation%2Binside%2Bthe%2Bmodel.jpeg http://www.nabble.com/file/p22180394/qq%2Bplot%2Bwith%2Bthe%2Blog%2Btransformation%2Boutside%2Bthe%2Bmodel.jpeg -- View this message in context: http://www.nabble.com/Syntax-in-taking-log-to-transfrom-the-data-to-fit-Gaussian-distribution-tp22179656p22180394.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
