Rosetta Code:Village Pump/BBC BASIC FFT possible error

From JohnMC. I am new to Rosetta Code, but was pleased to find an implementation of the Fast Fourier Transform FFT in many languages including BBC BASIC. I have used this. It works with the given data example, but seems to fail with other data. I made this change to 16 input points:

     DIM Complex{r#, i#}
     DIM in{(15)} = Complex{}, out{(15)} = Complex{}
     REM DATA 1, 1, 1, 1, 0, 0, 0, 0

     DATA  0, 0, 0, 0.2, 0.4, 0.6, 0.8, 1, 0.96, 0.84, 0.64, 0.36, 0, 0, 0, 0

     PRINT "Input (real, imag):"
     FOR I% = 0 TO 15
       READ in{(I%)}.r#
       PRINT in{(I%)}.r# "," in{(I%)}.i#
     NEXT

     PROCfft(out{()}, in{()}, 0, 1, DIM(in{()},1)+1)

     PRINT "Output (real, imag):"
     FOR I% = 0 TO 15
       PRINT out{(I%)}.r# "," out{(I%)}.i#
     NEXT
     END

No other change should be needed. However the output is just a list of zeros, which is incorrect. Can anyone comment, please?

Fixed, thanks. RichardRussell (talk) 03:49, 21 April 2023 (UTC)