The results of Plot ROC is strange

can someone correct my code. I tried to draw ROC but when I run it, the plot is not normal as usual. this is the code

data = [170 66 ; 160 50 ; 170 63 ; 173 61 ; 168 58 ; 184 88 ; 189 94 ; 185 88 ]

   labels=[0;0;0;0;0;1;1;1];
  opts = '-s 0 -t 2 -c 32 -g  1';    %# libsvm training options
  nfold=5;
  indices = crossvalind('Kfold', labels, nfold);
  cp=classperf(labels)
  acc = zeros(nfold,1);
      for i=1:nfold
          testIdx = (indices == i); trainIdx = ~testIdx;
            trainLabel = labels(trainIdx);
            trainData = data(trainIdx,:);
            testData=data(testIdx,:);
            testLabel=labels(testIdx);  

            model = svmtrain(trainLabel, trainData, opts);
  [predTestLabel, acc, decVals] = svmpredict(testLabel, testData, model);
  acc = mean(predTestLabel == testLabel);
  cmTest = confusionmat(testLabel,predTestLabel)
      cp=classperf(cp,predTestLabel,testIdx);
      end
  a=cp.CountingMatrix
  result_accuracy=mean(akurasi)
  % plot(1-specificity,sensitivity)
  [FPR, TPR, Thr, AUC, OPTROCPT]  = perfcurve(testLabel,decVals(:,1),1);
  figure
  plot(FPR, TPR, 'or-')
  xlabel('FP rate (FPR, 1-Specificity)'); ylabel('TP rate (TPR, Sensitivity)')
  title('ROC for classification')
  grid on;

Iam still confused how to put the variabel in this

[FPR, TPR, Thr, AUC, OPTROCPT]  = perfcurve(testLabel,decVals(:,1),1);

does someone have any idea how to solve this ??? thank you

[nur zawatil isqi]

Have u find the solution? Why you don't use plotroc? its' seem simpler.