A tangent function is used as an activation function to
calculate the hidden layer output and a linear function to
calculate the output [15] and [16]. An example of linear
transfer function and tangent transfer function are shown in
Figure 5 (a) and (b) respectively.
The tangent function was used as transfer function of the
single hidden layer that is described by Equation (9) and
directed in Figure (5) (b) [17].