/ featweighted-svm --username avenkatesan2005/code/Svmclassification.m

  1function Svmclassification
  2% Example MultiClass SVM Classifiction
  3% "One against Others"
  4%
  5%
  6%
  7clc;
  8clear all;
  9close all;
 10
 11
 12%--------------------------------------------------
 13%n=;
 14sigma=1;
 15
 16% Location of the data.
 17subjects = {'../mock-data/wesubj1.mat','../mock-data/wesubj2.mat','../mock-data/wesubj3.mat','../mock-data/wesubj4.mat','../mock-data/wesubj5.mat'};
 18
 19%% Compute the Feature Vectors.
 20% Create the features, for each activity, for
 21% each sample for each subject.
 22for subj = 1:5
 23    load(subjects{subj});
 24    feat = [];
 25    label = [];
 26    for activity =  1: 5
 27        for i = 1 : actionsample{activity}.tsamples            
 28            temp = [];
 29            
 30                temp = [temp computestatfeatures([actionsample{activity}.sample{i}.acc1,actionsample{activity}.sample{i}.acc2])];
 31                      
 32                %temp = [temp computefirstderivativehist(actionsample{activity}.sample{i}.acc1)];                
 33                %temp = [temp computerawhist(actionsample{activity}.sample{i}.acc1)];
 34                
 35            feat = [feat;temp];
 36            label = [label; activity];
 37        end       
 38    end
 39    save(sprintf('feat%d.mat',subj),'feat','label');
 40end
 41
 42% Perform a 5 fold cross validation on the feature vectors (histograms)
 43% using SVM.
 44% Variable for storing the confusion matrix.
 45cfmatrix = zeros(5);
 46%% SVM Classification.
 47for fold = 1:5
 48%     if fold == 4
 49%         continue;
 50%     end;
 51    % Create the train and test data set.
 52    trdata = [];
 53    trlabel = [];
 54    tstdata = [];
 55    tstlabel = [];
 56    trdata_norm= [];
 57    tstdata_norm= [];
 58    for j = 1 : 5
 59        load(sprintf('feat%d.mat',j));
 60        % Subject Independent
 61        if fold == j
 62            tstdata = feat;
 63            tstlabel = label;
 64          else
 65            trdata = [trdata;feat];
 66            trlabel = [trlabel;label];
 67        end       
 68    end
 69
 70  %Normalize the trdata and tstdata before running SVM training
 71  
 72    for i= 1: 39   %size(trdata,2)
 73        trdata_norm(:,1)=(trdata(:,1)-min(trdata(:,1)))/(max(trdata(:,1))-min(trdata(:,1)));
 74        if (max(trdata(:,i))-min(trdata(:,i)))~= 0
 75        trdata_norm(:,i)= (trdata(:,i)-min(trdata(:,i)))/(max(trdata(:,i))-min(trdata(:,i)));
 76        else
 77            trdata_norm(:,i)= trdata(:,i);
 78        end
 79    end
 80
 81    for i= 1: 39  %size(tstdata,2)
 82        if (max(tstdata(:,i))-min(tstdata(:,i)))~= 0
 83        tstdata_norm(:,i)= (tstdata(:,i)-min(trdata(:,i)))/(max(trdata(:,i))-min(trdata(:,i)));
 84        else
 85          tstdata_norm(:,i)= tstdata(:,i);  
 86        end
 87    end
 88
 89    %xapp=trdata_norm;
 90    xapp=trdata_norm;
 91    yapp= trlabel;
 92
 93    nbclass=5;
 94    [n1, n2]=size(xapp);
 95
 96    %-----------------------------------------------------
 97    %   Learning and Learning Parameters
 98    c = 1;
 99    lambda = 1e-7;
100    kerneloption= 2;
101    kernel='gaussian';
102    verbose =0;
103
104    % % %---------------------One Against All algorithms----------------
105    nbclass=5;
106    [xsup,w,b,nbsv]=svmmulticlassoneagainstall(xapp,yapp,nbclass,c,lambda,kernel,kerneloption,verbose);
107    [ypred_trn] = svmmultival(xapp,xsup,w,b,nbsv,kernel,kerneloption);
108    fprintf( '\nRate of correct class in training data : %2.2f \n',100*sum(ypred_trn==yapp)/length(yapp)); 
109
110    %-------------------------------------------------------
111    % Testing
112    %-------------------------------------------------------
113    xtest=tstdata_norm;
114
115    [ypred,maxi] = svmmultival(xtest,xsup,w,b,nbsv,kernel,kerneloption);
116    accuracy(fold)=100*sum(ypred==tstlabel)/length(tstlabel);
117    tcmatrix = computeconfusionmatrix(tstlabel,ypred);
118    cfmatrix = cfmatrix + tcmatrix;
119end
120%% Display the results.
121% Display Accuracy
122disp('Results with SVM');
123disp(sprintf('Accuracy over 5 folds'));
124disp(accuracy);
125disp(sprintf('Overall Accuracy over 5 folds %f ',(sum(accuracy)/5)));
126% Display Confusion Matrix
127disp(sprintf('Confusion Matrix'));
128disp(cfmatrix);
129
130function cfmatrix = computeconfusionmatrix(ytest,yest)
131
132    % this function computes the confusion matrix, given the estimated and
133    % actual labels.
134    cfmatrix = zeros(max(ytest),max(ytest));
135    for i = 1 : size(ytest,1)
136        cfmatrix(ytest(i),yest(i)) = cfmatrix(ytest(i),yest(i)) + 1;
137    end    
138return;
139
140function derivhist = computefirstderivativehist(data)
141    % centers for the histogram
142    centers = -50:50;
143    l = data(2:end,:);
144    d = data(1:end-1,:)-l;
145    histx = hist(d(:,1),centers);
146    histy = hist(d(:,2),centers);
147    histz = hist(d(:,3),centers);
148    derivhist = [histx/sum(histx) histy/sum(histy) histz/sum(histz)];
149return;
150
151function rawhist = computerawhist(data)
152    % centers for the histogram
153    % X - Axis
154    centersx = 100:450;
155    % Y - Axis
156    centersy = 0:700;
157    % Z - Axis
158    centersz = 250:600;
159    histx = hist(data(:,1),centersx);
160    histy = hist(data(:,2),centersy);
161    histz = hist(data(:,3),centersz);
162    rawhist = [histx/sum(histx) histy/sum(histy) histz/sum(histz)];
163return;
164
165function feature = computestatfeatures(data)
166    fnorm=true;
167
168    % mean of the data
169    m = mean(data);
170
171    % variance of the data
172    v = var(data);
173
174    % correlation between the axis.
175    c = corr(data);
176
177    % absolute value of the fourier transform.
178    fftdata = abs(fft(data));
179
180    % remove the mean value.
181    fftdata = fftdata(2:end,:);
182
183    % energy.
184    e = sum(fftdata.^2)/size(fftdata,1);
185
186    % spectral entropy
187    fftdata = 1 + fftdata/size(data,1);
188    temp = [fftdata(:,1)/sum(fftdata(:,1)), fftdata(:,2)/sum(fftdata(:,2)),...
189                                            fftdata(:,3)/sum(fftdata(:,3)),...
190                                            fftdata(:,4)/sum(fftdata(:,4)),...
191                                            fftdata(:,5)/sum(fftdata(:,5)),...
192                                            fftdata(:,6)/sum(fftdata(:,6))];
193    ent = -sum(temp.*log(temp),1);
194    feature = [m v c(1,2:6) c(2,3:6) c(3,4:6) c(4,5:6) c(5,6) e ent];
195return;