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Added complex words and fft
Added some floating point primitives

    1: \           *** Fast Fourier Transformation ***        15may93py
    2: 
    3: require complex.fs
    4: 
    5: : Carray ( -- )  Create 0 ,  DOES> @ swap complex' + ;
    6: Carray values
    7: Carray expix
    8: 
    9: : r+ BEGIN 2dup xor -rot and dup WHILE 1 rshift REPEAT  drop ;
   10: : reverse  ( n -- )  2/ dup dup 2* 1
   11:   DO  dup I < IF  dup values I values 2dup z@ z@ z! z! THEN
   12:       over r+  LOOP  2drop ;
   13: 
   14: \ reverse carry add                                    23sep05py
   15: 8 Value #points
   16: : realloc ( n addr -- )
   17:     dup @  IF  dup @ free throw  THEN  swap allocate throw swap ! ;
   18: : points  ( n --- )  dup to #points dup complex' dup
   19:   ['] values >body realloc  2/
   20:   ['] expix  >body realloc
   21:   dup 0 DO  0e 0e I values z!  LOOP
   22:   1e 0e 0 expix z! 2/ dup 2/ dup 2/ dup 1+ 1
   23:   ?DO  pi I I' 1- 2* 2* fm*/ fsincos fswap   I expix z!  LOOP
   24:   ?DO  I' I - 1- expix z@ fswap    I 1+ expix z!  LOOP  dup 2/
   25:   ?DO  I' I -    expix z@ fswap fnegate fswap
   26:                                     I    expix z!  LOOP ;
   27: : .values  ( -- )  precision  4 set-precision
   28:   #points 0 DO  I values z@ z. cr  LOOP  set-precision ;
   29: : .expix  ( -- )   precision  4 set-precision
   30:   #points 2/ 0 DO  I expix z@ z. cr  LOOP  set-precision ;
   31: ' .values ALIAS .rvalues
   32: 
   33: \ FFT                                                  23sep05py
   34: 
   35: : z2dup+ zover zover z+ ;
   36: 
   37: : butterfly ( cexpix addr1 addr2 -- cexpix )
   38:   zdup over z@ z* dup z@ z2dup+ z! zr- z! ;
   39: : butterflies ( cexpix step off end start -- )
   40:   ?DO  dup I + values I values butterfly
   41:   over +LOOP  zdrop drop ;
   42: : fft-step ( n flag step steps -- n flag step )
   43:   0 DO  I 2 pick I' */ 2/ expix z@
   44:         2 pick IF  fnegate  THEN  I' 2 pick I butterflies
   45:   LOOP ;
   46: 
   47: \ FFT                                                  23sep05py
   48: 
   49: : (fft ( n flag -- )  swap dup reverse 1
   50:   BEGIN  2dup >  WHILE  dup 2* swap fft-step
   51:   REPEAT  2drop drop ;
   52: 
   53: : normalize ( -- )  #points dup s>f 1/f
   54:   0 DO  I values dup z@ 2 fpick zscale z!  LOOP  fdrop ;
   55: 
   56: : fft  ( -- )  #points  true (fft ;
   57: : rfft ( -- )  #points false (fft ;
   58: