If `r`

is a number, `square(r)`

is a shortcut for creating a window object
representing the square
\([0,r] \times [0,r]\).
It is equivalent to the command
`owin(c(0,r),c(0,r))`

.

If `r`

is a vector of length 2, then
`square(r)`

creates the square with `x`

and `y`

coordinates
ranging from `r[1]`

to `r[2]`

.

`unit.square`

creates the unit square
\([0,1] \times [0,1]\).
It is equivalent to
`square(1)`

or `square()`

or `owin(c(0,1),c(0,1))`

.

These commands are included for convenience,
and to improve the readability of some code.