why my predicted output is negative in ANN.

why my predicted output is negative in ANN. there is no negative value in the data.

x = input';

t = output';

trainFcn = 'trainlm';

hiddenLayerSize = 40;

net = fitnet(hiddenLayerSize,trainFcn);

net.divideParam.trainRatio = 80/100;

net.divideParam.valRatio = 10/100;

net.divideParam.testRatio = 10/100;

[net,tr] = train(net,x,t);

y = net(x);

e = gsubtract(t,y);

performance = perform(net,t,y)

[Debraj Maji]

Hi @Sunita

Can you please share the data you used to train the network?