A 500 by 3 matrix in which the first column is the classification and
the remaining columns are two data from a simulation of two crossed
elliptical Gaussians.

## Examples

```
# This dataset was created as follows
# \donttest{
n <- 250
set.seed(0)
cross <- rbind(matrix(rnorm(n*2), n, 2) %*% diag(c(1,9)),
matrix(rnorm(n*2), n, 2) %*% diag(c(1,9))[,2:1])
cross <- cbind(c(rep(1,n),rep(2,n)), cross)
# }
```