myclass() function
added July 22, 2010
Code File
The code for the myclass() function is contained in the file classfunction.R. You can source the file directly into R by calling
source("http://www.biostat.jhsph.edu/~pmurakam/classfunction.R")
The code is licensed under the GNU General Public License version 3, or (at your option) any later version.
Manual page
Description:
This function is a quick and safe way to convert the class of a scalar or vector variable.
It can convert to character, factor, numeric, or integer, but is of most use when converting
to numeric or integer, when there can be problems with converting from factors if not done right.
Usage:
goodclass(x,whatclass)
Arguments:
x - scalar or vector variable
whatclass - desired class
Example:
dat <- data.frame(cbind(letters[1:10],seq(1,5.5,by=.5)))
dat$col3 <- as.numeric(1:10)
dat$col4 <- factor(11:20)
dat$col5 <- factor(21:30)
dat$col6 <- seq(6,10.5,by=.5)
dat$col7 <- factor(rep(c("A","B"),5),levels=c("B","A"))
for(j in 1:ncol(dat)) print(class(dat[,j]))
classes <- c("character","numeric","integer","number","numeric","number","factor")
for(j in 1:ncol(dat)) dat[,j] <- goodclass(dat[,j],classes[j])
for(j in 1:ncol(dat)) print(class(dat[,j]))
levels(dat$col7) #factor levels are retained as well.