Hi Robin, >> I ... can't get lm to work despite reading the help. I can get it to work >> with a single >> explanatory variable, EG model <- lm(data$admissions~data$maxitemp)
I'll answer just the second of your questions. Advice: don't just read the help file, look at the examples and run them; look at how the calls are made. lm() and many other programs use (or can use) the ?formula interface, so learn how to use it. For your "example," rather do ## EGModel <- lm(admissions ~ maxitemp, data = data) where data is your data set (to avoid confusion call it something else, e.g. mydata). To add another variable/predictor, which should be in your data frame (for simplicity) called data, simply do EGModel <- lm(admissions ~ maxitemp+another.var, data = data) If your maxitemp(s) occur at different sites, then you might be interested in a nested model EGModel1 <- lm(admissions ~ site/maxitemp - 1, data = data) EGModel2 <- lm(admissions ~ site*maxitemp, data = data) ## alt. parameterization anova(EGModel1, EGModel2) anova(EGModel, EGModel1, EGModel2, test="Chi") This shows part of the power of using the formula interface. HTH, Mark. Williams, Robin wrote: > > Hi all, > Thanks for the help with my previous post. > I have just two more questions for the minute. > I think I said in a previous post that I like to use the terminal, > i.e. run rterm.exe. On exiting the terminal, I am asked if I want to > save the workspace. If I hit y (yes), the workspace is just saved as > .rdata in my working directory, does anyone know how I can name it > directly from the terminal? > More importantly, I can't then open this file from the terminal. > Obviously loading the file from windows explorer brings up the GUI. > Anyone know the command I need? All I can think of doing is adding > rterm.exe to my path and running it from the command prompt (adding the > file as an argument to my command), but surely there is an easy way to > do this from R? Of course I would like to have the terminal open and > open and close various workspaces in one session, without wanting to > restart R all the time. > > Finally, I rather embarrasingly can't get lm to work despite reading > the help. I can get it to work with a single explanatory variable, EG > model <- lm(data$admissions~data$maxitemp) > but how to include a second explanatory variable (minitemp)? I keep > getting errors. Surely I don't need to use > c(data$maxitemp,data$minitemp) etc? > > All help greatly appreciated - I am getting there slowly! > > > Robin Williams > Met Office summer intern - Health Forecasting > [EMAIL PROTECTED] > > > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > > -- View this message in context: http://www.nabble.com/Just-2-more-questions---for-now%21-tp18629686p18630709.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.
