comparison toolboxes/MIRtoolbox1.3.2/somtoolbox/som_drsignif.m @ 0:e9a9cd732c1e tip

first hg version after svn

+function sig = som_drsignif(sigmea,Cm)
+
+% SOM_DRSIGNIF Significance measure from confusion matrix between two clusters and a rule.
+%
+% sig = som_drsignif(sigmea,Cm)
+% 
+%  sigmea   (string) significance measure: 'accuracy', 
+%                    'mutuconf' (default), or 'accuracyI'.
+%                    (See definitions below).
+%  Cn                Vectorized confusion matrix, or a matrix of such vectors.
+%           (vector) [a, c, b, d] (see below)
+%           (matrix) [[a1,c1,b1,d1], ..., [an,cn,bn,dn]]
+%
+%  sig      (vector) length=n, significance values 
+%
+% The confusion matrix Cm below between group (G) and contrast group (not G)
+% and rule (true - false) is used to determine the significance values:
+%
+%          G    not G    
+%       ---------------    accuracy  = (a+d) / (a+b+c+d)
+% true  |  a  |   b   |    
+%       |--------------    mutuconf  =  a*a  / ((a+b)(a+c)) 
+% false |  c  |   d   | 
+%       ---------------    accuracyI =   a   / (a+b+c)
+%
+% See also  SOM_DREVAL, SOM_DRMAKE.
+
+% Contributed to SOM Toolbox 2.0, March 4th, 2002 by Juha Vesanto
+% Copyright (c) by Juha Vesanto
+% http://www.cis.hut.fi/projects/somtoolbox/
+
+% Version 2.0beta juuso 040302
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%% input arguments
+
+true_x     = Cm(:,1); % x     = in group
+false_x    = Cm(:,2); % false = rule is false
+true_y     = Cm(:,3); % true  = rule is true
+false_y    = Cm(:,4); % y     = not in group
+
+true_items = true_x + true_y; 
+x_items    = true_x + false_x; 
+all_items  = true_x + false_x + true_y + false_y; 
+true_or_x  = x_items + true_items - true_x; 
+
+switch sigmea, 
+case 'mutuconf',
+    % mutual confidence, or relevance (as defined in WSOM2001 paper)
+    sig = zeros(size(true_x)); 
+    i = find(true_items>0 & x_items>0); 
+    sig(i) = (true_x(i).^2) ./ (true_items(i).*x_items(i)); 
+case 'accuracy', 
+    % accuracy 
+    sig = (true_x + false_y) ./ all_items;
+case 'accuracyI', 
+    % accuracy such that false_y is left out of consideration
+    sig = true_x./true_or_x;
+otherwise, 
+    error(['Unrecognized significance measures: ' sigmea]);
+end 
+
+return;