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Text File  |  1998-10-30  |  4.8 KB  |  133 lines
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  4. ccccfffffffftttt2222ddddiiii,,,,zzzzfffffffftttt2222ddddiiii((((3333FFFF))))                                        ccccfffffffftttt2222ddddiiii,,,,zzzzfffffffftttt2222ddddiiii((((3333FFFF))))
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  8. NNNNAAAAMMMMEEEE
  9.      ccccfffffffftttt2222ddddiiii,,,, zzzzfffffffftttt2222ddddiiii ---- initialize the coefficient array for complex-to-
  10.      complex 2D FFT modules.
  11.  
  12. SSSSYYYYNNNNOOOOPPPPSSSSYYYYSSSS
  13.      _F_O_R_T_R_A_N _S_P_E_C_I_F_I_C_A_T_I_O_N
  14.      ssssuuuubbbbrrrroooouuuuttttiiiinnnneeee CCCCFFFFFFFFTTTT2222DDDDIIII(((( nnnn1111,,,, nnnn2222,,,, ccccooooeeeeffffffff ))))
  15.      iiiinnnntttteeeeggggeeeerrrr                  nnnn1111,,,, nnnn2222
  16.      ccccoooommmmpppplllleeeexxxx             ccccooooeeeeffffffff((((((((nnnn1111++++11115555)))) ++++ ((((nnnn2222++++11115555))))))))
  17.  
  18.      ssssuuuubbbbrrrroooouuuuttttiiiinnnneeee ZZZZFFFFFFFFTTTT2222DDDDIIII(((( nnnn1111,,,, nnnn2222,,,, ccccooooeeeeffffffff ))))
  19.      iiiinnnntttteeeeggggeeeerrrr                  nnnn1111,,,, nnnn2222
  20.      ddddoooouuuubbbblllleeee ccccoooommmmpppplllleeeexxxx      ccccooooeeeeffffffff((((((((nnnn1111++++11115555)))) ++++ ((((nnnn2222++++11115555))))))))
  21.  
  22.      _C _S_P_E_C_I_F_I_C_A_T_I_O_N
  23.      ####iiiinnnncccclllluuuuddddeeee <<<<fffffffftttt....hhhh>>>>
  24.      ccccoooommmmpppplllleeeexxxx ****ccccfffffffftttt2222ddddiiii(((( iiiinnnntttt nnnn1111,,,, iiiinnnntttt nnnn2222,,,, ccccoooommmmpppplllleeeexxxx ****ccccooooeeeeffffffff))));;;;
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  26.      zzzzoooommmmpppplllleeeexxxx ****zzzzfffffffftttt2222ddddiiii(((( iiiinnnntttt nnnn1111,,,, iiiinnnntttt nnnn2222,,,, zzzzoooommmmpppplllleeeexxxx ****ccccooooeeeeffffffff))));;;;
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  29. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  30.      Initialize the coefficient array which is used in the 2D FFT modules.
  31.      This array contains the different twiddle factors and the factorization
  32.      of N1 and N2 into prime numbers.
  33.      As the FFT modules cfft2d or zfft2d only read the _c_o_e_f_f array, it may be
  34.      reused as long as necessary once it has been initialized.
  35.  
  36.      In C, if _p_t_r is NULL, _c_f_f_t_2_d_i or _z_f_f_t_2_d_i returns a pointer to an
  37.      allocated buffer.
  38.  
  39.      CFFT2DI should be used to initialize the coefficient array before any
  40.      call to CFFT2D
  41.      ZFFT2DI should be used to initialize the coefficient array before any
  42.      call to ZFFT2D
  43.  
  44. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS
  45.      NNNN1111 ---- Integer, the first dimension size of the 2D sequence.
  46.      Unchanged on exit.
  47.  
  48.      NNNN2222 ---- Integer, the second dimension size of the 2D sequence.
  49.      Unchanged on exit.
  50.  
  51.      CCCCOOOOEEEEFFFFFFFF ---- Array (C or Fortran) or NULL pointer(C).
  52.  
  53. EEEExxxxaaaammmmpppplllleeee ooooffff CCCCaaaalllllllliiiinnnngggg SSSSeeeeqqqquuuueeeennnncccceeee
  54.      Initializing a coefficient array for complex-to-complex FFTs of size 200
  55.      x 300.
  56.  
  57.      _F_o_r_t_r_a_n :
  58.           complex coeff((200+15)+(300+15))
  59.           call cfft2di( 200, 300, coeff)
  60.  
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  63.                                                                         PPPPaaaaggggeeee 1111
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  70. ccccfffffffftttt2222ddddiiii,,,,zzzzfffffffftttt2222ddddiiii((((3333FFFF))))                                        ccccfffffffftttt2222ddddiiii,,,,zzzzfffffffftttt2222ddddiiii((((3333FFFF))))
  71.  
  72.  
  73.  
  74.      _C :
  75.           #include <fft.h>
  76.           complex *coeff;
  77.           coeff = cfft2di( 200, 300, NULL);
  78.  
  79. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  80.           fft, cfft2d, zfft2d
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  129.                                                                         PPPPaaaaggggeeee 2222
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