|| package:hmatrix

horizontal concatenation
>>> ident 3 ||| konst 7 (3,4)
(3><7)
[ 1.0, 0.0, 0.0, 7.0, 7.0, 7.0, 7.0
, 0.0, 1.0, 0.0, 7.0, 7.0, 7.0, 7.0
, 0.0, 0.0, 1.0, 7.0, 7.0, 7.0, 7.0 ]