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 argumentstrue_x     = Cm(:,1); % x     = in groupfalse_x    = Cm(:,2); % false = rule is falsetrue_y     = Cm(:,3); % true  = rule is truefalse_y    = Cm(:,4); % y     = not in grouptrue_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;