--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/classes/@rational/fromPzmodel.m	Wed Nov 23 19:22:13 2011 +0100
@@ -0,0 +1,86 @@
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% FUNCTION:    fromPzmodel
+%
+% DESCRIPTION: Construct a rational from a pzmodel
+%
+% CALL:        r = fromPzmodel(a, pl)
+%
+% PARAMETER:   pl   - plist
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+function r = fromPzmodel(r, pli)
+  
+  VERSION = '$Id: fromPzmodel.m,v 1.11 2011/08/15 12:41:45 hewitson Exp $';
+  
+  
+  % get pzmodel info
+  ii = rational.getInfo('rational', 'From Pzmodel');
+  
+  % Set the method version string in the minfo object
+  ii.setMversion([VERSION '-->' ii.mversion]);
+  
+  % Combine input plist with default values
+  pl = applyDefaults(ii.plists, pli);
+  
+  % Set fields
+  pzm = find(pl, 'pzmodel');
+  
+  %--- Convert to rational
+  
+  % get normalising gains
+  pg = 1;
+  for jj=1:numel(pzm.poles)
+    if pzm.poles(jj).q > 0.5
+      pg = pg .* 4*pi*pi*pzm.poles(jj).f*pzm.poles(jj).f;
+    else
+      pg = pg .* 2*pi*pzm.poles(jj).f;
+    end
+  end
+  zg = 1;
+  for jj=1:numel(pzm.zeros)
+    if pzm.zeros(jj).q > 0.5
+      zg = zg .* 4*pi*pi*pzm.zeros(jj).f*pzm.zeros(jj).f;
+    else
+      zg = zg .* 2*pi*pzm.zeros(jj).f;
+    end
+  end
+  % construct rational terms
+  if isempty(pzm.poles) % in case on no poles
+    den = 1;
+  else
+    den = poly(vertcat(pzm.poles(:).ri))./pg;
+  end
+  if isempty(pzm.zeros) % in case on no zeros
+    num = pzm.gain;
+  else
+    num = pzm.gain.*poly(vertcat(pzm.zeros(:).ri))./zg;
+  end
+  
+  r.num = num;
+  r.den = den;
+  
+  % Override some properties from the input pzmodel
+  if isempty(pl.find('ounits'))
+    pl.pset('ounits', pzm.ounits);
+  end
+  
+  if isempty(pl.find('iunits'))
+    pl.pset('iunits', pzm.iunits);
+  end
+  
+  if isempty(pl.find('name'))
+    pl.pset('name', sprintf('rational(%s)', pzm.name));
+  end
+  
+  if isempty(pl.find('description'))
+    pl.pset('description', pzm.description);
+  end
+  
+  % Add history
+  r.addHistory(ii, pl, [], pzm.hist);
+  
+  % Set object properties
+  r.setObjectProperties(pl);
+  
+end