Colleages

I am running R 2.1.0 on a Mac (same problem occurs in Linux).  In  
some situations, I have mixed text/numeric data that is stored as  
characters in a matrix.  If I convert this matrix to a dataframe, the  
numeric data becomes factors, not what I intend.

     TEXT    <- paste("Text", 1:4, sep="")
     NUMBERS    <- 10 + 4:1
     MATRIX    <- cbind(TEXT, NUMBERS)
     FRAME    <- as.data.frame(MATRIX)

 > str(FRAME)
`data.frame':    4 obs. of  2 variables:
$ TEXT   : Factor w/ 4 levels "Text1","Text2",..: 1 2 3 4
$ NUMBERS: Factor w/ 4 levels "11","12","13",..: 4 3 2 1

One work-around is to write the matrix (or the dataframe) to a file,  
then read the file back using the as.is argument.
     write.table(MATRIX, "JUNK", row.names=F)
     NEWFRAME    <- read.table("JUNK", as.is=T, header=T)

 > str(NEWFRAME)
`data.frame':    4 obs. of  2 variables:
$ TEXT   : chr  "Text1" "Text2" "Text3" "Text4"
$ NUMBERS: int  14 13 12 11

This restores the NUMBERS to their intended mode (integers, not  
factors).  The text column is also not read as a factor (not a  
problem for me).

It appears that the function AsIs [I(x)] would enable me to  
accomplish this without the write/read steps.  However, it is not  
obvious to me how to implement I(x).  Can anyone advise?

Thanks in advance.

Dennis Fisher

Dennis Fisher MD
P < (The "P Less Than" Company)
Phone: 1-866-PLessThan (1-866-753-7784)
Fax: 1-415-564-2220
www.PLessThan.com


	[[alternative HTML version deleted]]


