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Text File  |  1996-03-14  |  4KB  |  133 lines
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  4. ssssccccfffffffftttt1111dddduuuuiiii,,,,ddddzzzzfffffffftttt1111dddduuuuiiii((((3333FFFF))))                                ssssccccfffffffftttt1111dddduuuuiiii,,,,ddddzzzzfffffffftttt1111dddduuuuiiii((((3333FFFF))))
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  8. NNNNAAAAMMMMEEEE
  9.      ssssccccfffffffftttt1111dddduuuuiiii,,,, ddddzzzzfffffffftttt1111dddduuuuiiii ---- initialize the coefficient array for real-to-
  10.      complex 1D 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 SSSSCCCCFFFFFFFFTTTT1111DDDDUUUUIIII(((( nnnn,,,, ccccooooeeeeffffffff ))))
  15.      iiiinnnntttteeeeggggeeeerrrr                  nnnn
  16.      rrrreeeeaaaallll           ccccooooeeeeffffffff((((nnnn++++11115555))))
  17.  
  18.      ssssuuuubbbbrrrroooouuuuttttiiiinnnneeee DDDDZZZZFFFFFFFFTTTT1111DDDDUUUUIIII(((( nnnn,,,, ccccooooeeeeffffffff ))))
  19.      iiiinnnntttteeeeggggeeeerrrr                  nnnn
  20.      rrrreeeeaaaallll****8888              ccccooooeeeeffffffff((((nnnn++++11115555))))
  21.  
  22.      _C _S_P_E_C_I_F_I_C_A_T_I_O_N
  23.      ####iiiinnnncccclllluuuuddddeeee <<<<fffffffftttt....hhhh>>>>
  24.      ffffllllooooaaaatttt ****ssssccccfffffffftttt1111dddduuuuiiii(((( iiiinnnntttt nnnn,,,, ffffllllooooaaaatttt ****ccccooooeeeeffffffff))));;;;
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  26.      ddddoooouuuubbbblllleeee ****ddddzzzzfffffffftttt1111dddduuuuiiii(((( iiiinnnntttt nnnn,,,, ddddoooouuuubbbblllleeee ****ccccooooeeeeffffffff))));;;;
  27.  
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  29. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  30.      Initialize, the coefficient array which is used in the FFT modules.  This
  31.      array contains the different twiddle factors and the factorization of N
  32.      into prime numbers.
  33.      As the FFT modules scfft1d or dzfft1d only read the _c_o_e_f_f array, it may
  34.      be reused as long as necessary once it has been initialized.
  35.  
  36.      In C, if _p_t_r is NULL, _s_c_f_f_t_1_d_u_i or _d_z_f_f_t_1_d_u_i returns a pointer to an
  37.      allocated buffer.
  38.  
  39.      SCFFT1DUI should be used to initialize the coefficient array before any
  40.      call to SCFFT1DU
  41.      DZFFT1DUI should be used to initialize the coefficient array before any
  42.      call to DZFFT1DU
  43.  
  44. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS
  45.      NNNN ---- Integer. Specifies the length of the sequence to be transformed.
  46.       Unchanged on exit.
  47.  
  48.      CCCCOOOOEEEEFFFFFFFF ---- Array (C or Fortran) or NULL pointer(C).
  49.  
  50. EEEExxxxaaaammmmpppplllleeee ooooffff CCCCaaaalllllllliiiinnnngggg SSSSeeeeqqqquuuueeeennnncccceeee
  51.      Initializing a coefficient array for real-to-complex FFTs of size 200.
  52.  
  53.      _F_o_r_t_r_a_n :
  54.           float coeff(200+15)
  55.           call scfft1dui( 200, coeff)
  56.  
  57.      _C :
  58.           #include <fft.h>
  59.           float *coeff;
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  63.                                                                         PPPPaaaaggggeeee 1111
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  70. ssssccccfffffffftttt1111dddduuuuiiii,,,,ddddzzzzfffffffftttt1111dddduuuuiiii((((3333FFFF))))                                ssssccccfffffffftttt1111dddduuuuiiii,,,,ddddzzzzfffffffftttt1111dddduuuuiiii((((3333FFFF))))
  71.  
  72.  
  73.  
  74.          coeff = scfft1dui( 200, NULL);
  75.  
  76. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  77.           fft, scfft1du, dzfft1du
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  129.                                                                         PPPPaaaaggggeeee 2222
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