Define Similarity Matrix
weight.taxo computes a matrix whose entries [i, j] are set to 1
if x[i] == x[j], 0 otherwise.
weight.taxo2 computes a matrix whose entries [i, j] are set to 1
if x[i] == x[j] AND y[i] != y[j], 0 otherwise.
The diagonal [i, i] is always set to 0.
The returned matrix can be used as a weight matrix in
y may be vectors of
See further details in
weight.taxo(x) weight.taxo2(x, y)
a square numeric matrix.