Multiple Recodes in R

I am looking to recode a large number of variables, and figure I can probably use some sort of loop to do so. W开发者_JAVA百科hat throws me is how to programmatically name each variable (I just want to keep the var name and append ".rc".

Here is an example. Lets say I have a set of variables, var.1 to var.5. I am looking to create a new variable in my dataframe that is var.1.rc <- var.1 / sum(var.1 to var1.5). Ill do the same for the next variable, and so on.

I am new to R but this would be a HUGE step forward for me.

Is it possible. Best ways to do it? Any help will be much appreciated!

Regards,

Brock

If I understand you correctly, there is actually a pretty easy way to do this. Assuming your original data frame is called dat, you can do this:

dat.rc <- dat/rowSums(dat)
names(dat.rc) <- paste(names(dat), ".rc", sep="")
dat <- data.frame(dat,dat.rc)

You could try the following loop.

Here the eval(parse(text="")) allows you evaluate a pasted together string containing the various static and dynamic portions of the expression to create each new variable.

for (i in 1:5) {
 X<-paste("var.",i,".rc<-var.",i,"/(var.1+var.2+var.3+var.4+var.5)",sep="")
 eval(parse(text=X))
}