How modify numbers in a region by a multiplier?

[Seweryn Kokot]

Hi,

I would like to modify numbers in a region/buffer by a given multiplier.

Imagine that I have some numbers

33.444 3333 4433.4443 3344 .34234

and I want them multiplied for example by 0.1

to receive

3.3444 333.3 443.34443 334.4 .034234

I tried with this function I wrote, but it doesn't work properly.
Any idea why?

(defun my-multiply-numbers-in-region-or-buffer (multiplier)
  (interactive "nGive multiplier: ")
  (let (beg end object)
        (if (use-region-p)
        (progn
          (setq object "region")
          (setq beg (region-beginning))
          (setq end (region-end)))
      (setq object "buffer")
      (setq beg (point-min))
      (setq end (point-max)))
        (goto-char beg)
        (while (re-search-forward "\\([0-9]*\\.?[0-9]*\\)" end t)
          (replace-match (format "%.3f" (* (string-to-number (match-string 1)) 
multiplier))))
        (message "Numbers in %s modified by multiplier %s." object 
multiplier)))