Merging Two Matrixes... in LISP
- by abidikgubidik
(defun merge-matrix (matrix-1 matrix-2)
(if (not (or (eql (matrix-rows matrix-1) (matrix-rows matrix-2)) (null matrix-1) (null matrix-2))) (error "Invalid dimensions."))
(cond
((null matrix-1) (copy-tree matrix-2))
((null matrix-2) (copy-tree matrix-1))
(t (let ((result (copy-tree matrix-1)))
(dotimes (i (matrix-rows matrix-1))
(setf (nth i result) (nconc (nth i result) (nth i matrix-2))))
result))))
(merge-matrix '((3 1) (1 3)) '((4 2) (1 1)))
* - EVAL: variable NULL has no value
I receive an error like that how I can fix the problem, thanks
