Reputation: 179
I have a matrix in R that looks something like
T F T T F
F T F T T
T T T F F
What I want to do is to change, say, the first 2 columns to all T's. So, I want the output to look like:
T T T T F
T T F T T
T T T F F
Is there an easy way to do this? I'm new to R, so any help is appreciated!
Upvotes: 1
Views: 449
Reputation: 3243
If it's a logical matrix, use
x[,1:2] <- T
or better, a more secure (and clear)
x[,1:2] <- TRUE
why more secure? because different users can assign different values to T
, eg
> T <- 0
> T == TRUE
[1] FALSE
but weird things are not allowed on TRUE
:
> TRUE <- 0
Error in TRUE <- 0 :
An example of harmful error could be in function defaults definition, eg
my.print <- function(val = T) {
cat(val, "\n")
}
T <- "foo"
my.print()
# foo
Upvotes: 3