Function: math-identity-matrix-p

math-identity-matrix-p is a byte-compiled function defined in calc-ext.el.gz.

Signature

(math-identity-matrix-p MAT &optional MUL)

Source Code

;; Defined in /usr/src/emacs/lisp/calc/calc-ext.el.gz
;;; True if MAT is an identity matrix.
(defun math-identity-matrix-p (mat &optional mul)
  (if (math-square-matrixp mat)
      (let ((a (if mul
                   (nth 1 (nth 1 mat))
                 1))
            (n (1- (length mat)))
            (i 1))
        (while (and (<= i n)
                    (math-ident-row-p (nth i mat) i a))
          (setq i (1+ i)))
        (if (> i n)
            a
          nil))))