This is a utility function mostly for internal use.
Usage
fp_scale(fp, fct)
Value
A vector representing the factor range in scaled units; scales
must have been added with fp_add_scale. If scales are not
available, the range in coded units is returned (i.e. c(-1,1))
Arguments
fp
The factorial plan object
fct
The standard name of the factor as a string (e.g. "A", or "B", etc.)