compan — Companion matrix
compan returns the companion matrix of the argument matrix.
If the argument is an (n+1)-vector, the companion matrix is nxn. If
the argument is a scalar, say s, then compan(s) is the
sxs matrix formed by taking the companion of
[1, 2,…, s + 1]. If
the argument is a matrix, but is not a vector, an internal conversion
to vector format is done.
This is not an built-in function. This function
is normally loaded on start-up from the compan.r file in the
standard rlib directory. Use of the -r option, incorrectly
setting the RLAB_LIB_DIR environmental variable, or modifying
compan.r may make this function unavailable.
Subsections