matlab - Neural network doesn't return values below 0.5 with logsig -

i want classify 2 classes neural network. since outputs 0 or 1, using (or trying t use) 'logsig' output function. problem when that, simulations end being between 0.5 , 1. if entering logsig function positive.

ps: training set , testing set composed of normalized values.

here do:

t = [0.8*ones(1,50) 0.2*ones(1,50)]; %define net net = newff(trainset,t,n,{'tansig','logsig'},'trainscg'); net.trainparam.epochs = 100; net.trainparam.goal = 0; %train net net = train(net,trainset,t); %test net %%on testing set outputs = sim(net,testset)