--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/classes/+utils/@math/intfact.m	Wed Nov 23 19:22:13 2011 +0100
@@ -0,0 +1,107 @@
+% INTFACT computes integer factorisation
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% INTFACT tries to find two integers, P and Q, that satisfy
+%
+%          y = P/Q * x
+%
+%   >> [p,q] = intfact(y,x)
+%
+% The following call returns a parameter list object that contains the
+% default parameter values:
+%
+% >> pl = intfact(utils, 'Params')
+%
+% The following call returns a string that contains the routine CVS version:
+%
+% >> version = intfact(utils,'Version')
+%
+% The following call returns a string that contains the routine category:
+%
+% >> category = intfact(utils,'Category')
+%
+% VERSION: $Id: intfact.m,v 1.9 2009/02/06 12:03:52 hewitson Exp $
+%
+% M Hewitson 26-05-08
+%
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+function varargout = intfact(varargin)
+  
+  % Get input sample rates
+  fs2 = floor(1e10*varargin{1});
+  fs1 = floor(1e10*varargin{2});
+  
+  g = gcd(fs2,fs1);
+  
+  varargout{1} = fs2/g;
+  varargout{2} = fs1/g;
+  
+  return
+  
+  % Get min and max fs
+  x = max(fs1,fs2);
+  y = min(fs1,fs2);
+  
+  % If we already have two integers then it's easy
+  if rem(fs2,1) == 0 && rem(fs1,1) == 0
+    P = fs2;
+    Q = fs1;
+    % Get the greatest common divisor
+    g = gcd(P,Q);
+    % factor that out
+    P = P / g;
+    Q = Q / g;
+    % If fs1 and fs2 are factors of each other, then it's easy
+  elseif  rem(fs1,fs2) == 0
+    P = fs1/fs2;
+    Q = 1;
+  elseif rem(fs2,fs1) == 0
+    Q = fs2/fs1;
+    P = 1;
+    % Otherwise we search for two integers
+  else
+    % Start from N=0
+    N = 0;
+    s = x * 10^N;
+    % Now compute initial P and Q
+    if fs2 > fs1
+      P  = 10^N;
+      Q  = s / y;
+    else
+      Q  = 10^N;
+      P  = s / y;
+    end
+    % Now look for the integers
+    while rem(s,1) > 0 || rem(P,1) > 0 || rem(Q,1) > 0
+      s = x * 10^N;
+      % Now compute P and Q
+      if fs2 > fs1
+        P  = 10^N;
+        Q  = s / y;
+      else
+        Q  = 10^N;
+        P  = s / y;
+      end
+      N = N+1;
+    end
+    
+    % Get the greatest common divisor
+    g = gcd(P,Q);
+    
+    % factor that out
+    P = P / g;
+    Q = Q / g;
+  end
+  
+  % Set outputs
+  if nargout == 2
+    varargout{1} = P;
+    varargout{2} = Q;
+  else
+    error('### Incorrect number of outputs');
+  end
+  
+end
+% END
\ No newline at end of file