title: How do i design a high pass filters in MATLAB without using the builtin function?
body: <p>i'm just not sure how to draw the frequency response (H) of the high pass filter? after drawing the frequency response I can get the b coefficient by taking the ifft of (H).
  So yeah, for a low pass filter, with a cutoff frequency of say pi/2 : the frequency response code will be <code>H = exp(-1*j*w*4).*(((0 &lt;= w) &amp; (w&lt;= pi/2)) | ((2*pi - pi/2 &lt;= w) &amp; (w&lt;=2*pi));</code>
  since the response is "1" between 0 and pi/2 and between (2*pi - pi/2) and 2*pi. 
  Can you help me write H for a high pass filter?
  Thanx in advance.</p>