Compute Suitable k1 x k2 Layout for Plotting
magic.dim.RdFor 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.
See also
primeFactors and bestCombination which are
internally used to complete the task.
n2mfrow is a similar function from package grDevices.