IFFT! Scaling Error
[email protected] Mon, 05 Apr 2004 07:45:06 -0400
| Newsgroups | gmane.lisp.matlisp.user |
|---|---|
| Message-ID | <[email protected]> |
All,
1. I noted a 1/N scaling error in IFFT! in the CVS code. This was
not present in my local working copy. I suspect I caused this
some time back and apologize.
2. Can someone verify this change and update CVS? The simple test
I used was (m:ifft! (m:fft (m:ones 8 3))) and (m:ifft! (m:fft (m:ones 8 1)))
3. The diff's are...
*** /home/mak/src/matlisp/src/fft.lisp 2003-02-24 17:30:21.000000000 -0500
--- /usr/local/src/matlisp/src/fft.lisp 2004-04-02 14:07:09.000000000 -0500
***************
*** 395,401 ****
(if (row-or-col-vector-p x)
(progn
(zfftb n (store x) wsave)
! x)
;; IFFT by column
(scal! (/ (float n 1d0))
--- 395,401 ----
(if (row-or-col-vector-p x)
(progn
(zfftb n (store x) wsave)
! (scal! (/ (float n 1d0)) x))
;; IFFT by column
(scal! (/ (float n 1d0))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
tnx
mike
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