[R] Log transformation and -Inf values for use in glm()
Paul Warren Simonin
Paul.Simonin at uvm.edu
Fri Feb 6 22:25:37 CET 2009
Hello,
I am writing regarding log transformation of data in a single
matrix column, and subsequent use of these data in a glm model fit. I
have a data matrix in which I am using the log function to transform
the values. This transformation results in -Inf values in some places,
though. I then receive an error when this matrix is used in the glm
function, and would like to know this can be avoided.
I have attempted several methods already including the use of
na.exclue commands in the glm statement:
> DistributionT<-glm(EarlyLn$yoyras~EarlyLn$temp,family=gaussian(link
> = "identity"),na.exclude)
I have also attempted to use the is.finite command:
EarlyLn$yoyras<-EarlyLn[is.finite(EarlyLn$yoyras)==T,]
I know another option would be to use a type of find and replace
command to remove entire rows of the matrix that contain 0's (before
log transformation) or -Inf (after transformation), but I do not know
how this is done.
Thank you for any advice or tips regarding conducting this
transformation and feeding the data matrix into glm.
Sincerely,
Paul S.
More information about the R-help
mailing list