src/math/matrices.lisp

   1
   2 (defun mtrix-transpose (mtrix)
   3   (apply #'mapcar #'list mtrix))
   4
   5 (defun mtrix-addn (&rest matrs)
   6   (apply #'mapcar #'tuple-addn matrs))
   7
   8 (defun mtrix-subtrn (&rest matrs)
   9   (apply #'mapcar #'tuple-subtrn matrs))
  10
  11 (defun scalar-mtrix-multn (k a)
  12   "Multiply a scalar /k/ and matrix /a/."
  13   (mapcar
  14     (lambda (arow)
  15       (scalar-tuple-multn k arow))
  16     a))
  17
  18 (defun mtrix-mult2n (a b)
  19   "Multiply 2 matrices."
  20   (mapcar
  21     (lambda (arow)
  22       (apply #'tuple-addn
  23              (mapcar #'scalar-tuple-multn
  24                      arow b)))
  25     a))
  26
  27 (defun mtrix-multn (&rest mats)
  28   "Standard matrix multiplication."
  29   (do ((a (car mats) (mtrix-mult2n a (car tomult)))
  30        (tomult (cdr mats) (cdr tomult)))
  31     ((endp tomult) a)))
  32
  33 (defun mtrix-coltuple-multn (a u)
  34   (declare (inline dot-prod))
  35   "Multiply matrix /a/ and column vector /u/."
  36   (loop :for row :in a
  37         :collect (dot-prod row u)))
  38
  39