adaboost_te.m

boost算法

function [L,hits] = ADABOOST_te(adaboost_model,te_func_handle,test_set,...
                                true_labels)
%
% ADABOOST TESTING
%
%  [L,hits] = ADABOOST_te(adaboost_model,te_func_handle,train_set,
%                         true_labels)
%
%           'te_func_handle' is a handle to the testing function of a
%           learning (weak) algorithm whose prototype is shown below.
%
%           [L,hits,error_rate] = test_func(model,test_set,sample_weights,true_labels)
%                    model: the output of train_func
%                    test_set: a KxD dimensional matrix, each of whose row is a
%                        testing sample in a D dimensional feature space.
%                    sample_weights:  a Dx1 dimensional vector, the i-th entry 
%                        of which denotes the weight of the i-th sample.
%                    true_labels: a Dx1 dimensional vector, the i-th entry of which
%                        is the label of the i-th sample.
%                    L: a Dx1-array with the predicted labels of the samples.
%                    hits: number of hits, calculated with the comparison of L and
%                        true_labels.
%                    error_rate: number of misses divided by the number of samples.
%
%           It is the corresponding testing 
%           module of the function that is specified in the training phase.
%           'test_set' is a NxD matrix where N is the number of samples
%           in the test set and D is the dimension of the feature space.
%           'true_labels' is a Nx1 matrix specifying the class label of
%           each corresponding sample's features (each row) in 'test_set'.
%           'adaboost_model' is the model that is generated by the function
%           'ADABOOST_tr'.
%
%           'L' is the likelihoods that are assigned by the 'ADABOOST_te'.
%           'hits' is the number of correctly predicted labels.
%
%        Specific Properties That Must Be Satisfied by The Function pointed
%        by 'func_handle'
%        ------------------------------------------------------------------
%
% Notice: Labels must be positive integer values from 1 upto the number classes.
%
% Bug Reporting: Please contact the author for bug reporting and comments.
%
% Cuneyt Mertayak
% email: [e-mail]
% version: 1.0
% date: 21/05/2007
%

hypothesis_n = length(adaboost_model.weights);
sample_n = size(test_set,1);
class_n = length(unique(true_labels));
temp_L = zeros(sample_n,class_n,hypothesis_n);		% likelihoods for each weak classifier

% for each weak classifier, likelihoods of test samples are collected
for i=1:hypothesis_n
	[temp_L(:,:,i),hits,error_rate] = te_func_handle(adaboost_model.parameters{i},...
													 test_set,ones(sample_n,1),true_labels);
	temp_L(:,:,i) = temp_L(:,:,i)*adaboost_model.weights(i);
end

L = sum(temp_L,3);
hits = sum(likelihood2class(L)==true_labels);