*** empty log message ***

migram.m

@@ -16,13 +16,16 @@ function [c_out, l_out, t_out] = migram(varargin)
 %   I = MIGRAM(A,B,MAXLAG,WINDOW,NOVERLAP,NBINS) calculates the mutual
 %   information based on histograms with the number of bins NBINS.
 %
+%   I = MIGRAM(...,'norm') calculates the renormalised mutual
+%   information, which is I/log(NBINS) and ensures a value range [0 1].
+%
 %   [I,L,T] = MIGRAM(...) returns a column of lag L and one of time T
 %   at which the mutual information is computed. L has length equal 
 %   to the number of rows of I, T has length k.
 %
 %   I = MIGRAM(A,B) calculates windowed mutual information using defeault
 %   settings; the defeaults are MAXLAG = floor(0.1*N), WINDOW = floor(0.1*N),
-%   NOVERLAP = 0 and NBINS = 10. You can tell CORRGRAM to use the defeault 
+%   NOVERLAP = 0 and NBINS = 10. You can tell MIGRAM to use the defeault 
 %   for any parameter by leaving it off or using [] for that parameter, e.g. 
 %   MIGRAM(A,B,[],1000).
 %
@@ -44,7 +47,7 @@ function [c_out, l_out, t_out] = migram(varargin)
 % $Revision$
 
 
-error(nargchk(2,6,nargin))
+error(nargchk(2,7,nargin))
 verbose = 0;
 
 x = varargin{1}; y = varargin{2};
@@ -66,32 +69,40 @@ maxlag = floor(nx/10);
 window = floor(nx/10);
 noverlap = 0;
 nbins = 10;
+norm = 0;
+
+i_num = find(cellfun('isclass',varargin,'double'));
+i_char = find(cellfun('isclass',varargin,'char'));
 
-if length(varargin) > 2 & ~isempty(varargin{3})
-    maxlag = varargin{3};
+if length(i_num) > 2 & ~isempty(varargin{i_num(3)})
+    maxlag = varargin{i_num(3)};
     if maxlag < 0, error('Requires positive integer value for maximum lag.'), end
     if length(maxlag) > 1, error('Requires MAXLAG to be a scalar.'), end
 end
 
-if length(varargin) > 3 & ~isempty(varargin{4})
-    window = varargin{4};
+if length(i_num) > 3 & ~isempty(varargin{i_num(4)})
+    window = varargin{i_num(4)};
     if window <= 0, error('Requires positive integer value for window length.'), end
     if length(window) > 1, error('Requires WINDOW to be a scalar.'), end
 end
 
-if length(varargin) > 4 & ~isempty(varargin{5})
-    noverlap = varargin{5};
+if length(i_num) > 4 & ~isempty(varargin{i_num(5)})
+    noverlap = varargin{i_num(5)};
     if noverlap < 0, error('Requires positive integer value for NOVERLAP.'), end
     if length(noverlap) > 1, error('Requires NOVERLAP to be a scalar.'), end
     if noverlap >= window, error('Requires NOVERLAP to be strictly less than the window length.'), end
 end
 
-if length(varargin) > 5 & ~isempty(varargin{6})
-    noverlap = varargin{6};
+if length(i_num) > 5 & ~isempty(varargin{i_num(6)})
+    noverlap = varargin{i_num(6)};
     if nbins <= 0, error('Requires positive integer value for NBINS.'), end
     if length(nbins) > 1, error('Requires NBINS to be a scalar.'), end
 end
 
+% normalise the result
+for i = 1:length(i_char)
+    if strcmpi(varargin(i_char(i)), 'norm'), norm = 1; end
+end
 
 
 % prepare time delayed signals
@@ -108,7 +119,6 @@ if verbose, h = waitbar(0,'Compute mutual information'); end
 
 % -MAXLAG:0
 [Yi dummy] = buffer(Y(:,1),window,noverlap,'nodelay'); 
-Yi = normalize(Yi);
 if exist('accumarray','builtin') == 5
     for i = 1:size(X,2), if verbose, waitbar(cnt/(2*size(X,2))), end
         [Xi dummy] = buffer(X(:,i),window,noverlap,'nodelay');
@@ -148,6 +158,12 @@ warning on
 t = (1:nx/size(Xi,2):nx)';
 l = (-maxlag:maxlag)';
 
+% if result has to be normalised
+if norm
+    C = C / log(nbins);
+end
+
+
 % display and output result
 if nargout == 0
     newplot
@@ -236,4 +252,3 @@ function Z = MI5(x, y, nbins)
         Z(i) = Ix + Iy - Ixy;
     end    
     
-