7 October   2023   7:48:05.848 AM      
 
fft_serial():
  FORTRAN77 version
  Demonstrate an implementation of the Fast Fourier Transform
  of a complex data vector,
 
  Accuracy check:
 
    FFT ( FFT ( X(1:N) ) ) == N * X(1:N)
 
             N      NITS    Error         Time          Time/Call     MFLOPS
 
             2     10000    0.7859E-16    0.118500E-02    0.5925E-07     168.8    
             4     10000    0.1210E-15    0.311800E-02    0.1559E-06     256.6    
             8     10000    0.6821E-16    0.557000E-02    0.2785E-06     430.9    
            16     10000    0.1439E-15    0.132910E-01    0.6646E-06     481.5    
            32      1000    0.1331E-15    0.360100E-02    0.1800E-05     444.3    
            64      1000    0.1777E-15    0.768600E-02    0.3843E-05     499.6    
           128      1000    0.1929E-15    0.148390E-01    0.7419E-05     603.8    
           256      1000    0.2092E-15    0.281130E-01    0.1406E-04     728.5    
           512       100    0.1927E-15    0.561600E-02    0.2808E-04     820.5    
          1024       100    0.2312E-15    0.128570E-01    0.6429E-04     796.5    
          2048       100    0.2445E-15    0.273370E-01    0.1367E-03     824.1    
          4096       100    0.2477E-15    0.610810E-01    0.3054E-03     804.7    
          8192        10    0.2571E-15    0.128090E-01    0.6405E-03     831.4    
         16384        10    0.2736E-15    0.279260E-01    0.1396E-02     821.4    
         32768        10    0.2924E-15    0.578140E-01    0.2891E-02     850.2    
         65536        10    0.2834E-15    0.126194        0.6310E-02     830.9    
        131072         1    0.3142E-15    0.257530E-01    0.1288E-01     865.2    
 
fft_serial():
  Normal end of execution.
 
 7 October   2023   7:48:06.402 AM