R help - Oct 2003 - List of lm objects

Hi R-Helpers:

I?m trying to fit the same linear model to a bunch of variables in a data
frame, so I was trying to adapt the codes John Fox, Spencer Graves and Peter
Dalgaard  proposed and discused yesterday on this e-mail list:

for (y in df[, 3:5]) {
mod = lm(y ~ Trt*Dose, data = x, contrasts = list(Trt contr.sum, Dose =
contr.sum))
Anova(mod, type = "III")
} ##  by John Fox

or
for (myname in names(myframe)){
  mycall <- substitute(lm(myvar~etc.etc.....),list(myvar=as.name(myname)))
  myfit <- eval(mycall)
  print(summary(myfit))
} ## by Peter Dalgaard

But instead of printing summary or Anova results, I need to generate a list
containing all the lm() objects.
Is that possible? How?

Thanks, Gabriela.

"CENDOYA, Gabriela" <gcendoya at balcarce.inta.gov.ar> writes:
> for (myname in names(myframe)){
>   mycall <-
substitute(lm(myvar~etc.etc.....),list(myvar=as.name(myname)))
>   myfit <- eval(mycall)
>   print(summary(myfit))
> } ## by Peter Dalgaard
> 
> But instead of printing summary or Anova results, I need to generate a list
> containing all the lm() objects.
> Is that possible? How?
Very easily:

f <- function(myname){
  mycall <- substitute(lm(myvar~etc.etc.....),list(myvar=as.name(myname)))
  myfit <- eval(mycall)
  print(summary(myfit))
}

lapply(names(myframe),f)

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907

How about the following:

AList <- vector(mode="list", length=3)
for(i in 1:3){
y <- df[,i])
mod <- lm(y~Tr*Dose, data=x, contrasts=list(Tr=contr.sum, Dose=contr.sum))
AList[[i]] <- Anova(mod, type="III")
}

hope this helps. spencer graves

CENDOYA, Gabriela wrote:
>Hi R-Helpers:
>
>I?m trying to fit the same linear model to a bunch of variables in a data
>frame, so I was trying to adapt the codes John Fox, Spencer Graves and Peter
>Dalgaard  proposed and discused yesterday on this e-mail list:
>
>for (y in df[, 3:5]) {
>mod = lm(y ~ Trt*Dose, data = x, contrasts = list(Trt >contr.sum, Dose =
contr.sum))
>Anova(mod, type = "III")
>} ##  by John Fox
>
>or
>for (myname in names(myframe)){
>  mycall <-
substitute(lm(myvar~etc.etc.....),list(myvar=as.name(myname)))
>  myfit <- eval(mycall)
>  print(summary(myfit))
>} ## by Peter Dalgaard
>
>But instead of printing summary or Anova results, I need to generate a list
>containing all the lm() objects.
>Is that possible? How?
>
>Thanks, Gabriela.
>
>______________________________________________
>R-help at stat.math.ethz.ch mailing list
>https://www.stat.math.ethz.ch/mailman/listinfo/r-help
>  
>

Thank you!!!
all the answers were really useful!!! and taught me something different!!

Gabriela