For a given number k, magic.dim provides a vector
containing two elements, the number of rows (k1) and columns (k2),
respectively, which can be used to set the
dimension of a single graphic device so that k1*k2 plots can be
drawn by row (or by column) on the device.
magic.dim(k)numeric vector with two elements
an integer
primeFactors and bestCombination which are
internally used to complete the task.
n2mfrow is a similar function from package grDevices.