Hi Ninlawat,
I understand that you want to compute different network performance metrics on the train, test, and validation data after training a neural network object in MATLAB.
The following code illustrates one way to achieve the same:
% dummy data
input = rand(1, 100); % 1 feature, 100 samples
target = 2 * input + 1 + 0.1 * randn(1, 100); % Linear relation with some noise
% Define the feedforward network
net = feedforwardnet(10); % 10 hidden neurons
% Set up the data division
net.divideFcn = 'dividerand';
net.divideParam.trainRatio = 0.6;
net.divideParam.valRatio = 0.2;
net.divideParam.testRatio = 0.2;
% Train the network
[net, tr] = train(net, input, target);
% Get the network outputs
outputs = net(input);
% Separate the outputs for training, validation, and testing
trainOutputs = outputs(tr.trainInd);
valOutputs = outputs(tr.valInd);
testOutputs = outputs(tr.testInd);
% Separate the targets for training, validation, and testing
trainTargets = target(tr.trainInd);
valTargets = target(tr.valInd);
testTargets = target(tr.testInd);
% Calculate and display R-square, MAE, and MSE for each dataset
datasets = {'train', 'val', 'test'};
outputsList = {trainOutputs, valOutputs, testOutputs};
targetsList = {trainTargets, valTargets, testTargets};
for i = 1:length(datasets)
dataset = datasets{i};
outputs = outputsList{i};
targets = targetsList{i};
% R-square
SS_res = sum((targets - outputs).^2);
SS_tot = sum((targets - mean(targets)).^2);
R_square = 1 - SS_res / SS_tot;
% Mean Absolute Error (MAE)
MAE = mae(targets - outputs);
% Mean Square Error (MSE)
MSE = mse(net, targets, outputs);
% Display the results
fprintf('%s R-square: %.4f\n', dataset, R_square);
fprintf('%s MAE: %.4f\n', dataset, MAE);
fprintf('%s MSE: %.4f\n', dataset, MSE);
fprintf('\n');
end
You can refer the following documentation links for more infromation on the properties and functions used in the code above:
- mse - https://www.mathworks.com/help/deeplearning/ref/mse.html
- mae - https://www.mathworks.com/help/deeplearning/ref/mae.html
- divderand - https://www.mathworks.com/help/deeplearning/ref/dividerand.html
Hope this helps.
