%GETCOST Get classification cost matrix
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% [COST,LABLIST] = GETCOST(W)
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% Returns the classification cost matrix as set in the classifier W.
% An empty cost matrix is interpreted as equal costs for misclassification.
% In that case COST = ONES(C+1) - EYE(C+1) is returned, if C is the number
% of classes. Row C+1 and column C+1 in COST refer to unlabeld objects.
% In LABLIST the class labels are returned.
% Getcost will return [] when no costmatrix is defined.
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% If A has target labels an error is returned as in that case no classes
% and thereby no costs are defined.
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% See MAPPINGS