Computes ordinary or generalized least squares coefficients
over the permutations of an lm.rrpp
model fit with predefined random permutations.
For each coefficient vector, the Euclidean distance is calculated as an estimate of
the amount of change in Y, the n x p matrix of dependent variables; larger distances mean more change
in location in the data space associated with a one unit change in the model design, for the parameter
described. Random coefficients are based on either RRPP or FRPP, as defined by the
lm.rrpp
model fit. If RRPP is used, all distributions of coefficient vector distances are
based on appropriate null models as defined by SS type.
This function can be used to test the specific coefficients of an lm.rrpp fit. The test
statistics are the distances (d), which are also standardized (Z-scores). The Z-scores might be easier to compare,
as the expected values for random distances can vary among coefficient vectors (Adams and Collyer 2016).