Transfer function

Function

Range

Graph

Identity

$f=x$

[−∞, +∞]

Symmetrical Hard Limit

$f=signo\left(x\right)$

[−1, +1]

log Sigmoid

$f=\frac{1}{1+{\text{e}}^{-x}}$

[0, +1]

Hyperbolic Tangent Sigmoid

$f=\frac{{\text{e}}^x-{\text{e}}^{-x}}{{\text{e}}^x+{\text{e}}^{-x}}$

[−1, +1]