The function jj_abc(u) corresponds to j_abc but has a matrix argument u.
It acts on the first index in the same way as j_abc for all values of the second index.
function jj_abc extends Icons.Function; input Real[3, :] u "array of 3-vectors (voltage, current)"; output Real[3, size(u, 2)] y "array of rotated vectors (voltage, current)"; end jj_abc;