title: How can I get DFT/FFT output frequencies in Hertz?
body: <p>I want to develop musical notes detector as my degree project and I want to do it from scratch. I have written code for ".wav" file which extracts all info from that audio music file and gives me amplitude as a result.</p>
  
  <p>Then I have written a code for DFT - it gives me output as a complex number where one of the axis (real/imaginary) is amplitude/magnitude and other is Phase.</p>
  
  <p>Now the question I want the answer in frequency (in Hertz not in vector) so I can check whether my DFT gives me the proper output or not. How can i convert my DFT output into frequency ?</p>
  
  <p>I have to code this in C language and I don't want to use any built-in library</p>