Artifact e0dda0f9110997f9fe31475e7b8cfc2ffdbf3ff3143af2d4d87b0b05573b501f:

• File mtt/lib/control/PPP/ppp_butter.m — part of check-in [af3953deae] at 2021-03-01 11:39:42 on branch master — Cleanup repository after cvs2git conversion. (user: jeff@gridfinity.com, size: 465) [annotate] [blame] [check-ins using] [more...]
• File mttroot/mtt/lib/control/PPP/ppp_butter.m — part of check-in [182384e0d6] at 2001-04-02 15:02:35 on branch origin/master — Putting the PPP library under cvs (user: gawthrop@users.sourceforge.net, size: 465) [annotate] [blame] [check-ins using]

function pol = ppp_butter (order,radius)

  ## usage:  pol = cgpc_butter (order,radius)
  ##
  ## Butterworth polynomial of given order and pole radius
  ## Copyright (C) 1999 by P.J. Gawthrop

  ## 	$Id$	

  theta = pi/(2*order);		# Angle with real axis

  even = (floor(order/2)==order/2);
  if even
    pol=1; N=order/2;
  else
    pol=[1 radius]; N=(order-1)/2;
  endif
  
  for i=1:N
    pol=conv(pol, [1 2*radius*cos(i*theta) radius^2]);
  endfor

endfunction