# [Rd] Trouble with ifelse and if statement (PR#7962)

Martin Maechler maechler at stat.math.ethz.ch
Wed Jun 22 10:06:34 CEST 2005

```
<........nonsense non-bug report by Woolton........>

Marc> This is not a bug and yes you have missed something.

Marc> Read R FAQ 7.31 Why doesn't R think these numbers are equal?

Marc> http://grouper.ieee.org/groups/754/

thank you, Marc.

Marc> One possible solution:

>> i
Marc> [1] 0.08 0.00 0.33 0.00 0.00 0.00 0.00 0.33 0.00 0.00 0.08 0.08 0.20
Marc> [14] 0.00 0.13

Note that a slightly more recommended way for the following is

as.integer(sapply(i, function(x) isTRUE(all.equal(x, 0.33))))

using the    isTRUE(all.equal(...))  idiom
which I'd recommend quite generally.

Martin

>> ifelse(sapply(i, function(x) all.equal(x, 0.33)) == "TRUE", 1, 0)
Marc> [1] 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0

>> ifelse(sapply(i, function(x) all.equal(x, 0.08)) == "TRUE", 1, 0)
Marc> [1] 1 0 0 0 0 0 0 0 0 0 1 1 0 0 0

>> ifelse(sapply(i, function(x) all.equal(x, 0.2)) == "TRUE", 1, 0)
Marc> [1] 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0

Martin

```