Re: [R] splitting into multiple dataframes and then create a loop to work

2011-08-30 Thread Nilaya Sharma
Thank you for the help. My focus was to split data frame for a different function, not lm. I could provide detail of that lengthy function instead I provided the lm function. The comment were very helpful. Thanks; NIL On Mon, Aug 29, 2011 at 3:37 PM, Dimitris Rizopoulos

[R] splitting into multiple dataframes and then create a loop to work

2011-08-29 Thread Nilaya Sharma
Dear All Sorry for this simple question, I could not solve it by spending days. My data looks like this: # data set.seed(1234) clvar - c( rep(1, 10), rep(2, 10), rep(3, 10), rep(4, 10)) # I have 100 level for this factor var; yvar - rnorm(40, 10,6); var1 - rnorm(40, 10,4); var2 - rnorm(40,

Re: [R] splitting into multiple dataframes and then create a loop to work

2011-08-29 Thread Dennis Murphy
Hi: This is straightforward to do with the plyr package: # install.packages('plyr') library('plyr') set.seed(1234) df - data.frame(clvar = rep(1:4, each = 10), yvar = rnorm(40, 10, 6), var1 = rnorm(40, 10, 4), var2 = rnorm(40, 10, 4), var3 = rnorm(40, 5, 2),

Re: [R] splitting into multiple dataframes and then create a loop to work

2011-08-29 Thread Dimitris Rizopoulos
You can do this using function lmList() from package nlme, without having to split the data frames, e.g., library(nlme) mlis - lmList(yvar ~ . - clvar | clvar, data = df) mlis summary(mlis) I hope it helps. Best, Dimitris On 8/29/2011 5:37 PM, Nilaya Sharma wrote: Dear All Sorry for

Re: [R] splitting into multiple dataframes and then create a loop to work

2011-08-29 Thread Dennis Murphy
Hi: Dimitris' solution is appropriate, but it needs to be mentioned that the approach I offered earlier in this thread differs from the lmList() approach. lmList() uses a pooled measure of error MSE (which you can see at the bottom of the output from summary(mlis) ), whereas the plyr approach

Re: [R] splitting into multiple dataframes and then create a loop to work

2011-08-29 Thread Dimitris Rizopoulos
well, if a pooled estimate of the residual standard error is not desirable, then you just need to set argument 'pool' of lmList() to FALSE, e.g., mlis - lmList(yvar ~ . - clvar | clvar, data = df, pool = FALSE) summary(mlis) Best, Dimitris On 8/29/2011 9:20 PM, Dennis Murphy wrote: Hi: