This function returns the modulus of frequency response of function H.
 Frequently H will be a FIR filter.

  If  H    = [h0 h1 h2 ... h(M-1)] then your Z transform is:
  M2=floor(M/2);
  $H[Z] = h0 Z^{+M2} + h1 Z^{+M2-1} + ...  h(M-1) Z^{+M2-(M-1)}$ 
  and the function return $AH=|H[Z=e^{jW}]|$ for W from 0 to pi.


  After starting the main routine just type the following command at the
  prompt:
  AH=freqmod(H,N)
  [AH FREQN]=freqmod(H,N);
  
  Input:
  H     is a vector with the parameters of H function. 
  N     is the number of analysis points in the frequency response.
  Output:
  AH     is the modulus of frequency response of function H. 
         $AH=|H[Z=e^{jW}]|$ for W from 0 to pi.
  FREQN  [OPTIONAL] is the normalized frequency of points in AH, thus for the 
         point AH(id) we have W=FREQN(id)*pi.
  

  For help, bug reports and feature suggestions, please visit:
  http://nongnu.org/bsltl/

Package: bsltl