1 files changed, 83 insertions, 0 deletions
diff --git a/sourcecodes/bnt-master/SLP/examples/test_knn.m b/sourcecodes/bnt-master/SLP/examples/test_knn.m
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+++ b/sourcecodes/bnt-master/SLP/examples/test_knn.m
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+function [ratio, ratiominus, ratioplus, tps]  = test_knn(BD,BDT,class,K)
+% [epsilon, tps]  = test_knn(BD,BDT,class,K)
+%
+% epsilon = good classification rate on BDT,
+% tps = computation time,
+% BD = examples dataset using to find neighbors,
+% BDT = set of examples to class,
+% class = classification attribute number,
+% K = vote on the K nearest neighbor
+%
+% francois.olivier.c.h@gmail.com
+
+[N L]=size(BD);
+Ltest=size(BDT,2);
+fprintf(' test dataset size %d\r\n',Ltest);
+E=setdiff(1:N,class);
+place=0;
+%for k=K
+k=K;
+ place=place+1;
+ good=0;tic
+ for i=1:Ltest
+  %fprintf(' %d\r',i);
+  res=knn(BD(E,:)',BD(class,:)',[1 2],BDT(E,i)',k);
+  if res==BDT(class,i)
+    good=good+1;
+  end
+ end
+ tps(place)=toc;
+ epsilon(1,place)=k;
+ epsilon(2,place)=good/(Ltest);
+%end
+
+ratio = epsilon(2,place);
+[ratiominus ratioplus] = confiance(ratio,L);
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%�
+function [ypred]=knn(xapp,yapp,valY,X,k)
+% knn implementation
+%
+% USE : [ypred]=knn(xapp,yapp,valY,X,k)
+%
+% Vincent Guigue 08/01/03
+
+if nargin<4
+  error('too few argumemnts');
+elseif nargin<5
+  k=3;
+else
+  if mod(k,2)==0
+    error('k must be odd');
+  end
+end
+
+if size(xapp,2)~=size(X,2)
+  error('dimension incompatibility');
+end
+ndim = size(xapp,2);
+nptxapp = size(xapp,1);
+nptX = size(X,1);
+
+% distance de X a xapp :
+mat1 =  repmat(xapp, nptX,1);
+%mat21 = reshape(X',1,nptX*ndim)
+mat22 = repmat(X,1,nptxapp)';
+mat2 = reshape(mat22 ,ndim, nptxapp*nptX)';
+distance = mat1 - mat2 ;
+distance = sum(distance.^2,2);
+distance = reshape(distance,nptxapp,nptX);
+[val kppv] = sort(distance,1);
+% bilan sur les k premieres lignes
+kppv = reshape(kppv(1:k,:),k*nptX,1);
+Ykppv = yapp(kppv,1);
+Ykppv = reshape(Ykppv,k,nptX);
+% trouver le plus de reponses identique par colonne
+vote = [];
+for i=1:nptX
+  for j=1:length(valY)
+    vote(j,i)=size(find(Ykppv(:,i)==valY(j)),1);
+  end
+end
+[val ind]=max(vote,[],1);
+ypred = valY(ind);
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