load(lapack)$   /* This may hang up in wxMaxima, if this happens, use xMaxima or plain Maxima in a terminal */

a: matrix([12, -51,   4],
          [ 6, 167, -68],
          [-4,  24, -41])$

[q, r]: dgeqrf(a)$

mat_norm(q . r - a, 1);
4.2632564145606011E-14

/* Note: the lapack package is a lisp translation of the fortran lapack library */