identical(x, y)

Check whether x and y are identical objects.

- x – Any R object.
- y – Any R object.

Example. Below we show that we can recreate two identical sets of pseudorandom numbers — exactly — by setting the seed. We verify that the two sets are identical using the identical function.

> set.seed(5) > x <- rnorm(3) > x [1] -0.8408555 1.3843593 -1.2554919 > set.seed(5) > y <- rnorm(3) > y [1] -0.8408555 1.3843593 -1.2554919 > identical(x, y) [1] TRUE > z <- c(-0.8408555, 1.3843593, -1.2554919) > identical(x, z) [1] FALSE

The objects x and y are not just really similar; they are identical. If we investigated z, we would find that x and z are different due to rounding errors.

Tip. The identical function may be applied to complex R objects, including lists and functions.