How can i rescale every column in my data frame to a 0-100 scale? (in r)

Question

i am trying to get all the colums of my data frame to be in the same scale..

right now i have something like this... where a is on a 0-1 scale b is on a 100 scale and

Answer 1

Using scale, if dat is the name of your data frame:

## for one column
dat$a <- scale(dat$a, center = FALSE, scale = max(dat$a, na.rm = TRUE)/100)
## for every column of your data frame
dat <- data.frame(lapply(dat, function(x) scale(x, center = FALSE, scale = max(x, na.rm = TRUE)/100)))

For a simple case like this, you could also write your own function.

fn <- function(x) x * 100/max(x, na.rm = TRUE)
fn(c(0,1,0))
# [1]   0 100   0
## to one column
dat$a <- fn(dat$a)
## to all columns of your data frame
dat <- data.frame(lapply(dat, fn))