dat
data to rescale. matrix object, with elements as rows, and variables as columns (i.e. variables are rescaled).
span
new domain to which dat is rescaled. If type is numeric and length = 1: [-span, span] is used for all variables. If type is numeric and length = 2: [span[1], span[2]] is used for all variables. If a list object: [span[[1]]_i, span[[2]]_i] is used for each variable i.
oldspan
if NULL, old domains are computed from dat inspection. Otherwise, is structured as span and replaces inspected values for rescaling.