Function: calcFunc-taylor

calcFunc-taylor is an autoloaded and byte-compiled function defined in calcalg2.el.gz.

Signature

(calcFunc-taylor EXPR VAR NUM)

Source Code

;; Defined in /usr/src/emacs/lisp/calc/calcalg2.el.gz
(defun calcFunc-taylor (expr var num)
  (let ((x0 0) (v var))
    (if (memq (car-safe var) '(+ - calcFunc-eq))
	(setq x0 (if (eq (car var) '+) (math-neg (nth 2 var)) (nth 2 var))
	      v (nth 1 var)))
    (or (and (eq (car-safe v) 'var)
	     (math-expr-contains expr v)
	     (natnump num)
	     (let ((accum (math-expr-subst expr v x0))
		   (var2 (if (eq (car var) 'calcFunc-eq)
			     (cons '- (cdr var))
			   var))
		   (n 0)
		   (nfac 1)
		   (fprime expr))
	       (while (and (<= (setq n (1+ n)) num)
			   (setq fprime (calcFunc-deriv fprime v nil t)))
		 (setq fprime (math-simplify fprime)
		       nfac (math-mul nfac n)
		       accum (math-add accum
				       (math-div (math-mul (math-pow var2 n)
							   (math-expr-subst
							    fprime v x0))
						 nfac))))
	       (and fprime
		    (math-normalize accum))))
	(list 'calcFunc-taylor expr var num))))