Re: [R] question about formula for lm
Yet another solution: with(X,lm(get(Ytext)~Xvar)) On 14-Jun-07, at 5:18 PM, Greg Snow wrote: Try: lm( formula( paste( Ytext, '~ Xvar' ) ), data=X) -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare [EMAIL PROTECTED] (801) 408-8111 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Pedro Mardones Sent: Thursday, June 14, 2007 1:14 PM To: R-help@stat.math.ethz.ch Subject: [R] question about formula for lm Dear all; Is there any way to make this to work?: .x-rnorm(50,10,3) .y-.x+rnorm(50,0,1) X-data.frame(.x,.y) colnames(X)-c(Xvar,Yvar) Ytext-Yvar lm(Ytext~Xvar,data=X) # doesn't run lm(Yvar~Xvar,data=X) # does run The main idea is to use Ytext as input in a function, so you just type Yvar and the model should fit Also, I need to avoid the expression X$Yvar~X$Xvar Thanks for any idea PM __ R-help@stat.math.ethz.ch 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. __ R-help@stat.math.ethz.ch 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. -- Mike Lawrence Graduate Student, Department of Psychology, Dalhousie University Website: http://myweb.dal.ca/mc973993 Public calendar: http://icalx.com/public/informavore/Public The road to wisdom? Well, it's plain and simple to express: Err and err and err again, but less and less and less. - Piet Hein __ R-help@stat.math.ethz.ch 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.
Re: [R] question about formula for lm
On 6/14/07, Greg Snow [EMAIL PROTECTED] wrote: Try: lm( formula( paste( Ytext, '~ Xvar' ) ), data=X) That type of construction is perilously close to parse(paste(...)) and we know what Thomas said about that (see fortune(parse)). A safer way of constructing a formula from names stored in a character variable is substitute(foo ~ Xvar, list(foo = as.name(Ytext)) -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Pedro Mardones Sent: Thursday, June 14, 2007 1:14 PM To: R-help@stat.math.ethz.ch Subject: [R] question about formula for lm Dear all; Is there any way to make this to work?: .x-rnorm(50,10,3) .y-.x+rnorm(50,0,1) X-data.frame(.x,.y) colnames(X)-c(Xvar,Yvar) Ytext-Yvar lm(Ytext~Xvar,data=X) # doesn't run lm(Yvar~Xvar,data=X) # does run The main idea is to use Ytext as input in a function, so you just type Yvar and the model should fit Also, I need to avoid the expression X$Yvar~X$Xvar Thanks for any idea PM __ R-help@stat.math.ethz.ch 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. __ R-help@stat.math.ethz.ch 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. __ R-help@stat.math.ethz.ch 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.
Re: [R] question about formula for lm
A couple of easy ways are to create the calling sequence as a call or character string and then evaluate it: eval(bquote(lm(.(as.name(Ytext)) ~ Xvar, X))) eval(parse(text = paste(lm(, Ytext, ~ Xvar, X Note that these solutions both have the advantage over some of the prior solutions that the output from print.lm shows which variable was actually used after Call: eval(bquote(lm(.(as.name(Ytext)) ~ Xvar, X))) Call: lm(formula = Yvar ~ Xvar, data = X) --- This line comes out meaningfully!!! Coefficients: (Intercept) Xvar 0.3300 0.9729 On 6/14/07, Pedro Mardones [EMAIL PROTECTED] wrote: Dear all; Is there any way to make this to work?: .x-rnorm(50,10,3) .y-.x+rnorm(50,0,1) X-data.frame(.x,.y) colnames(X)-c(Xvar,Yvar) Ytext-Yvar lm(Ytext~Xvar,data=X) # doesn't run lm(Yvar~Xvar,data=X) # does run The main idea is to use Ytext as input in a function, so you just type Yvar and the model should fit Also, I need to avoid the expression X$Yvar~X$Xvar Thanks for any idea PM __ R-help@stat.math.ethz.ch 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. __ R-help@stat.math.ethz.ch 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.
Re: [R] question about formula for lm
Why not using: lm(X[[Ytext]]~Xvar,data=X) ThPe Pedro Mardones wrote: Dear all; Is there any way to make this to work?: .x-rnorm(50,10,3) .y-.x+rnorm(50,0,1) X-data.frame(.x,.y) colnames(X)-c(Xvar,Yvar) Ytext-Yvar lm(Ytext~Xvar,data=X) # doesn't run lm(Yvar~Xvar,data=X) # does run The main idea is to use Ytext as input in a function, so you just type Yvar and the model should fit Also, I need to avoid the expression X$Yvar~X$Xvar Thanks for any idea PM __ R-help@stat.math.ethz.ch 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. __ R-help@stat.math.ethz.ch 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.
Re: [R] question about formula for lm
First check the value of Ytext. Try Ytext - X$Yvar --- Pedro Mardones [EMAIL PROTECTED] wrote: Dear all; Is there any way to make this to work?: .x-rnorm(50,10,3) .y-.x+rnorm(50,0,1) X-data.frame(.x,.y) colnames(X)-c(Xvar,Yvar) Ytext-Yvar lm(Ytext~Xvar,data=X) # doesn't run lm(Yvar~Xvar,data=X) # does run The main idea is to use Ytext as input in a function, so you just type Yvar and the model should fit Also, I need to avoid the expression X$Yvar~X$Xvar Thanks for any idea PM __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] question about formula for lm
Try: lm( formula( paste( Ytext, '~ Xvar' ) ), data=X) -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare [EMAIL PROTECTED] (801) 408-8111 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Pedro Mardones Sent: Thursday, June 14, 2007 1:14 PM To: R-help@stat.math.ethz.ch Subject: [R] question about formula for lm Dear all; Is there any way to make this to work?: .x-rnorm(50,10,3) .y-.x+rnorm(50,0,1) X-data.frame(.x,.y) colnames(X)-c(Xvar,Yvar) Ytext-Yvar lm(Ytext~Xvar,data=X) # doesn't run lm(Yvar~Xvar,data=X) # does run The main idea is to use Ytext as input in a function, so you just type Yvar and the model should fit Also, I need to avoid the expression X$Yvar~X$Xvar Thanks for any idea PM __ R-help@stat.math.ethz.ch 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. __ R-help@stat.math.ethz.ch 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.
