title: FFT Algorithm C Code Explaination
body: <p><a href="http://www.tech.dmu.ac.uk/~eg/tensiometer/fft/fft.c" rel="nofollow">http://www.tech.dmu.ac.uk/~eg/tensiometer/fft/fft.c</a></p>
  
  <p><a href="http://www.tech.dmu.ac.uk/~eg/tensiometer/fft/fft_test.c" rel="nofollow">http://www.tech.dmu.ac.uk/~eg/tensiometer/fft/fft_test.c</a></p>
  
  <p>I have found a good working C Code for FFT Algorithm for converting Time Domain to Frequency Domain and vice versa in the above links. But I wanted to know the flowchart or step by step process of how this code works. I am trying to analyze the code with butterfly method of decimation in time for FFT but i am facing difficulties in understanding the code. The code is working very well and giving me the correct results but it would be very helpful to me if someone could give a brief or detailed explaination on how this code works.</p>
  
  <p>I am confused with the array and the pointers used in the fft.c code. Also I am not getting what are the variables <strong>offset</strong> and <strong>delta</strong> mean in the code. How the rectangular matrix of real and imaginary terms are considered/used in the code?? Please guide me.</p>
  
  <p>Thanks,
  Psbk</p>