 to generate a matrix <CODE>y</CODE> of output
vectors. Each row of <CODE>x</CODE> corresponds to one input vector and each
row of <CODE>y</CODE> corresponds to one output vector.

<p><CODE>[y, z] = mlpfwd(net, x)</CODE> also generates a matrix <CODE>z</CODE> of the hidden
unit activations where each row corresponds to one pattern.

<p><CODE>[y, z, a] = mlpfwd(net, x)</CODE> also returns a matrix <CODE>a</CODE> 
giving the summed inputs to each output unit, where each row
corresponds to one pattern