How to select only numeric columns from a data table

Another solution without with = FALSE is the .SDcols parameter:

x[, .SD, .SDcols = which(sapply(x, is.numeric))]

This also works:

x[, .SD, .SDcols = sapply(x, is.numeric)]

The current development version (as of 2020-04-16) also makes this one step simpler:

x[ , .SD, .SDcols = is.numeric]

data.table needs the with=FALSE to grab column numbers.

tokeep <- which(sapply(x,is.numeric))
x[ , tokeep, with=FALSE]

Related