--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/classes/@mfir/fromAO.m	Wed Nov 23 19:22:13 2011 +0100
@@ -0,0 +1,120 @@
+% create FIR filter from magnitude of input AO/fsdata
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% FUNCTION:    mfirFromAO
+%
+% DESCRIPTION: create FIR filter from magnitude of input AO/fsdata
+%
+% CALL:        f = mfirFromAO(a, pli, version, algoname)
+%
+% PARAMETER:   a:        Analysis object
+%              pli:      Parameter list object
+%              version:  cvs version string
+%              algoname: The m-file name (use the mfilename command)
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+function filt = fromAO(filt, pli)
+  
+  import utils.const.*
+  
+  VERSION = '$Id: fromAO.m,v 1.25 2011/08/15 11:37:04 hewitson Exp $';
+  ii = mfir.getInfo('mfir', 'From AO');
+  % Set the method version string in the minfo object
+  ii.setMversion([VERSION '-->' ii.mversion]);
+  
+  % Add default values
+  pl = applyDefaults(ii.plists, pli);
+  
+  % Get parameters
+  a      = find(pl, 'AO');
+  N      = find(pl, 'N');
+  win    = find(pl, 'Win');
+  method = find(pl, 'method');
+  
+  if ischar(win)
+    name = win;
+    wlen = pl.find('length');
+    % if the plist contains a window length (like history plists do), use
+    % it; otherwise use the filter order N.
+    if isempty(wlen)
+      wlen = N;
+    end
+    
+    if strcmpi(name, 'kaiser')
+      psll = pl.find('psll');
+      win = specwin(name, wlen, psll);
+    else
+      win = specwin(name, wlen);
+    end
+  end
+  
+  % Check that a.data is a fsdata object
+  if ~isa(a.data, 'fsdata')
+    error('### Please use an analysis object with a fsdata data object to create a mfir object.');
+  end
+  
+  fs = a.data.fs;
+  f  = a.data.getX;
+  xx = abs(a.data.getY);
+  
+  ffm = f/(fs/2);
+  switch lower(method)
+    case 'frequency-sampling'
+      % check window
+      if ischar(win)
+        if strcmpi(win, 'kaiser')
+          win = specwin(win, N+1, win.psll);
+        else
+          win = specwin(win, N+1);
+        end
+      end
+      
+      if length(win.win) ~= N+1
+        warning('!!! resizing window function to match desired filter order.');
+        if strcmpi(win.type, 'Kaiser')
+          win = specwin(win.type, N+1, win.psll);
+        else
+          win = specwin(win.type, N+1);
+        end
+      end
+      utils.helper.msg(msg.OPROC2, 'designing filter using frequency-sampling method [help fir2]');
+      mtaps = fir2(N, ffm, xx, win.win);
+    case 'least-squares'
+      error('### this design method is not working properly yet.');
+      if mod(length(ffm),2)
+        ffm = ffm(1:end-1);
+        xx  = xx(1:end-1);
+      end
+      utils.helper.msg(msg.OPROC2, 'designing filter using least-squares method [help firls]');
+      mtaps = firls(N, ffm, xx);
+    case 'parks-mcclellan'
+      error('### this design method is not working properly yet.');
+      utils.helper.msg(msg.OPROC2, 'designing filter using Parks-McClellan method [help firpm]');
+      mtaps = firpm(N, ffm, xx);
+    otherwise
+      error('### unknown filter design method.');
+  end
+  
+  % Make mfir object
+  filt.fs      = fs;
+  filt.a       = mtaps;
+  filt.gd      = (filt.ntaps+1)/2;
+  filt.histout = zeros(1,filt.ntaps-1);
+  
+  % Override some properties of the input plist
+  if isempty(pl.find('name'))
+    pl.pset('name', sprintf('fir(%s)', a.name));
+  end
+  if isempty(pl.find('description'))
+    pl.pset('description', a.description);
+  end
+  
+  % Add history
+  pl.remove('AO'); % because the input AO goes in the history
+  filt.addHistory(ii, pl, [], a.hist);
+  
+  % Set object properties
+  filt.setObjectProperties(pl);
+  
+end % function f = mfirFromAO(a, pli, version, algoname)