title: Test new data in NARX network MATLAB
body: <p>I have trained the NARX net in MATLAB with below code.I want to test the trained network from new inputs (testX) and targets (testY).But i am getting error in last line forecastLoad = sim(net, testX')';</p>
  
  <pre><code> X = tonndata(trainX,false,false);
   T = tonndata(trainY,false,false);
  
   inputSeries = X;
  
   targetSeries = T;
  
  % Create a Nonlinear Autoregressive Network with External Input
   inputDelays = 1:3;
  feedbackDelays = 1:3;
  hiddenLayerSize = 20;
  net = narxnet(inputDelays,feedbackDelays,hiddenLayerSize);
  
  % Prepare the Data for Training and Simulation
  % The function PREPARETS prepares time series data 
  
  [inputs,inputStates,layerStates,targets] = ... 
      preparets(net,inputSeries,{},targetSeries);
  
  % Set up Division of Data for Training, Validation, Testing
  net.divideParam.trainRatio = 70/100;
  net.divideParam.valRatio = 15/100;
  net.divideParam.testRatio = 15/100;
  
  % Train the Network
  [net,tr] = train(net,inputs,targets,inputStates,layerStates);
  %% 
  
  % Test the Network
  outputs = net(inputs,inputStates,layerStates);
  errors = gsubtract(targets,outputs);
  MAE = mae(errors);
  
  
   %Test on new data
    forecastLoad = sim(net, testX')';
    error = testY-forecastLoad;
  </code></pre>