- (or (natnump n)
- (math-reject-arg n 'fixnatnump))
- (let ((res (make-vector n 0))
- (vp vec)
- (wvec (Math-vectorp wts))
- (wp wts)
- bin)
- (while (setq vp (cdr vp))
- (setq bin (car vp))
- (or (natnump bin)
- (setq bin (math-floor bin)))
- (and (natnump bin)
- (< bin n)
- (aset res bin (math-add (aref res bin)
- (if wvec (car (setq wp (cdr wp))) wts)))))
- (cons 'vec (append res nil))))
+ (cond ((natnump n)
+ (let ((res (make-vector n 0))
+ (vp vec)
+ (wvec (Math-vectorp wts))
+ (wp wts)
+ bin)
+ (while (setq vp (cdr vp))
+ (setq bin (car vp))
+ (or (natnump bin)
+ (setq bin (math-floor bin)))
+ (and (natnump bin)
+ (< bin n)
+ (aset res bin
+ (math-add (aref res bin)
+ (if wvec (car (setq wp (cdr wp))) wts)))))
+ (cons 'vec (append res nil))))
+ ((Math-vectorp n) ;; n is a vector of midpoints
+ (let* ((bds (math-vector-avg n))
+ (res (make-vector (1- (length n)) 0))
+ (vp (cdr vec))
+ (wvec (Math-vectorp wts))
+ (wp wts)
+ num)
+ (while vp
+ (setq num (car vp))
+ (let ((tbds (cdr bds))
+ (i 0))
+ (while (and tbds (Math-lessp (car tbds) num))
+ (setq i (1+ i))
+ (setq tbds (cdr tbds)))
+ (aset res i
+ (math-add (aref res i)
+ (if wvec (car (setq wp (cdr wp))) wts))))
+ (setq vp (cdr vp)))
+ (cons 'vec (append res nil))))
+ (t
+ (math-reject-arg n "*Expecting an integer or vector"))))
+
+;;; Replace a vector [a b c ...] with a vector of averages
+;;; [(a+b)/2 (b+c)/2 ...]
+(defun math-vector-avg (vec)
+ (let ((vp (sort (copy-sequence (cdr vec)) 'math-beforep))
+ (res nil))
+ (while (and vp (cdr vp))
+ (setq res (cons (math-div (math-add (car vp) (cadr vp)) 2) res)
+ vp (cdr vp)))
+ (cons 'vec (reverse res))))