;;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; Base: 10 -*-
;;;; *************************************************************************
;;;; FILE IDENTIFICATION
;;;;
;;;; Name:          math.lisp
;;;; Purpose:       General purpose math functions
;;;; Programmer:    Kevin M. Rosenberg
;;;; Date Started:  Nov 2002
;;;;
;;;; $Id: math.lisp,v 1.3 2003/04/28 23:51:59 kevin Exp $
;;;;
;;;; This file, part of KMRCL, is Copyright (c) 2002 by Kevin M. Rosenberg
;;;;
;;;; KMRCL users are granted the rights to distribute and use this software
;;;; as governed by the terms of the Lisp Lesser GNU Public License
;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
;;;; *************************************************************************


(in-package :kmrcl)

(defun deriv (f dx)
  #'(lambda (x)
      (/ (- (funcall f (+ x dx)) (funcall f x))
	 dx)))

(defun sin^ (x)
    (funcall (deriv #'sin 1d-8) x))

;;; (sin^ pi)

(defmacro ensure-integer (obj)
  "Ensure object is an integer. If it is a string, then parse it"
  `(if (stringp ,obj)
      (parse-integer ,obj)
     ,obj))