title: Cant get two columns of scores in two class learning in SVM model in MATLAB
body: <p>Doing some machine learning with the data from <a href="https://www.kaggle.com/mlg-ulb/creditcardfraud" rel="nofollow noreferrer">https://www.kaggle.com/mlg-ulb/creditcardfraud</a> regarding credit card fraud.
  The class labels are: &quot;1= fraudulent&quot; and &quot;0= otherwise&quot;. I am using Support vector machine by &quot;fitcsvm()&quot; command in MATLAB where I suppose I am doing a &quot;two class learning&quot; since I have &quot;1&quot; and &quot;0&quot; in the class labels.
  However, when doing the &quot;predict(SVMmodel)&quot; , where SVMmodel is my trained SVM model as SVMmodel = fitcsvm(.....), to obtain the scores, I obtain one column vector, which is the case when you are dealing with, according to Mathworks, with one class learning. I am confused. Do I have one to two class learning or is my code wrong? It says I should obtain &quot;scores&quot; by [label,score] = predict(SVMModel,X) such that &quot;scores&quot; has two columns, since I am using two class learning, however, I only have 1 columne.
  I specify 'ClassNames',{'0','1'}); in the fitcsvm(...) function also. What can be the error?</p>
  <pre><code>data = readtable('clean_data.csv');
  split_size = 0.15; 
  N = size(data,1);
  split = false(N,1); 
  split(1:round(split_size*N)) = true;
  permutation = randperm(N); 
  split = split(permutation);
  trainingSet = data(~split,:); 
  testingSet = data(split,:); 
  trainingPredictors = trainingSet{:,2:29}; 
                                        
  trainingOutcomes = trainingSet{:,31}; 
                                    
  testingPredictors = testingSet{:,2:29};
  testingOutcomes = testingSet{:,31}; 
  X = trainingPredictors;
  y = trainingOutcomes;
  SVMModel = fitcsvm(X,y,'KernelFunction','rbf', 'KernelScale',sigmaOpts,...
  'BoxConstraint', boxOpts, 'ClassNames',{'0','1'}); 
  [predictedLabels,scores] = predict(SVMModel,testingPredictors); 
  </code></pre>
  <p>According to Mathwork documentation I should obtain two columns in the score array which corresponds to negative and positive classes. I only obtain 1 column. That is my issue, and I cannot see where the error is at.</p>
  <p>So I should get</p>
  <pre><code>scores(:,1) 
  
  scores(:,2) 
  </code></pre>