--- freqz.m.orig	2005-01-12 16:41:23.000000000 +0100
+++ freqz.m	2005-01-13 09:40:48.000000000 +0100
@@ -68,6 +68,10 @@
 ## than returning them.
 ## @end deftypefn
 
+## 12 JAN 2005: modified by <address@hidden>: 
+## -avoid recomputing length(a), length(b) when la, lb are available
+## -fix (inverted the polynomial order) such that 
+## 	[H1, W1]= freqz(B, A); [H2, W2]=freqz(B, A, W1) give the same result 
 ## Author: jwe ???
 
 function [h_r, w_r] = freqz (b, a, n, region, Fs)
@@ -125,6 +129,7 @@
     endif
     n = length (n);
     extent = 0;
+    q = exp(-j*w);
   elseif (strcmp (region, "whole"))
     w = 2 * pi * (0:n-1) / n;
     extent = n;
@@ -133,8 +138,8 @@
     extent = 2 * n;
   endif
 
-  if (length (b) == 1)
-    if (length (a) == 1)
+  if (1 == lb )
+    if (1 == la)
       hb = b * ones (1, n);
     else
       hb = b;
@@ -143,15 +148,15 @@
     hb = fft (postpad (b, extent));
     hb = hb(1:n);
   else
-    hb = polyval (postpad (b, k), exp (j*w));
+    hb = polyval (b(lb:-1:1), q);
   endif
-  if (length (a) == 1)
+  if (1 == la)
     ha = a;
   elseif (extent >= k)
     ha = fft (postpad (a, extent));
     ha = ha(1:n);
   else
-    ha = polyval (postpad (a, k), exp (j*w));
+    ha = polyval (a(la:-1:1), q);
   endif
   h = hb ./ ha;
   w = Fs * w / (2*pi);