How to standardize a data frame which contains both numeric and factor variables

Question

My data frame, my.data, contains both numeric and factor variables. I want to standardise just the numeric variables in this data frame.

> mydata2=data.frame(scale(my.data, center=T, scale=T))
Error in colMeans(x, na.rm = TRUE) : 'x' must be numeric

Could the standardising work by doing this? I want to standardise the columns 8,9,10,11 and 12 but I think I have the wrong code.

mydata=data.frame(scale(flowdis3[,c(8,9,10,11,12)], center=T, scale=T,))

Thanks in advance

Answer 1

Here is one option to standardize

 mydata[] <- lapply(mydata, function(x) if(is.numeric(x)){
                     scale(x, center=TRUE, scale=TRUE)
                      } else x)