--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/classes/+utils/@math/ri2fq.m	Wed Nov 23 19:22:13 2011 +0100
@@ -0,0 +1,24 @@
+% RI2FQ Convert complex pole/zero into frequency/Q pole/zero representation.
+%
+%  [f0, q]= ri2fq(c)
+%
+% M Hewitson 26-01-07
+%
+% $Id: ri2fq.m,v 1.3 2008/10/24 09:40:19 hewitson Exp $
+%
+
+function [f0, q]= ri2fq(c)
+  
+  if(nargin==0)
+    disp('usage: [f0, q]= ri2fq(c)');
+    return
+  end
+  
+  a = real(c(1));
+  b = imag(c(1));
+
+  f0 = sqrt(a^2 + b^2)/(2*pi);
+  q = 0.5*sqrt(1 + b^2/a^2);
+  
+end
+% END