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version 1.2, 2005/12/31 15:46:08	version 1.5, 2007/12/31 17:34:58
Line 1	Line 1
\ fast fourier transform	\ fast fourier transform

\ Copyright (C) 2005 Free Software Foundation, Inc.	\ Copyright (C) 2005,2007 Free Software Foundation, Inc.

\ This file is part of Gforth.	\ This file is part of Gforth.

Line 70 Carray expix	Line 70 Carray expix
BEGIN 2dup > WHILE dup 2* swap fft-step	BEGIN 2dup > WHILE dup 2* swap fft-step
REPEAT 2drop drop ;	REPEAT 2drop drop ;

: normalize ( -- ) #points dup s>f 1/f	: fftscale ( r -- )
0 DO I values dup z@ 2 fpick zscale z! LOOP fdrop ;	#points 0 DO I values dup z@ 2 fpick zscale z! LOOP fdrop ;
	: normalize ( -- ) #points s>f 1/f fftscale ;

: fft ( -- ) #points true (fft ;	: fft ( -- ) #points true (fft ;
: rfft ( -- ) #points false (fft ;	: rfft ( -- ) #points false (fft ;

	: hamming ( -- ) #points 0 DO
	I values dup z@ pi I #points fm/ fsin f2 f2 zscale z!
	LOOP ;