# megengine.functional.tanh¶

tanh(x)[源代码]

Element-wise $$\tanh(x)$$ function.

Calculates the hyperbolic tangent for each element $$x_i$$ of the input tensor $$x$$.

Equivalent to:

$\frac {\sinh(x)} {\cosh(x)} = \frac {e^{x}-e^{-x}} {e^{x}+e^{-x}}$

This function has domain [-infinity, +infinity] and codomain [-1, 1].

x – input tensor whose elements each represent a hyperbolic angle. Should have a floating-point data type.

a tensor containing the hyperbolic tangent of each element in $$x$$. The returned tensor must have a floating-point data type determined by 类型提升规则.

Special cases

For floating-point operands,

• If $$x_i$$ is NaN, the result is NaN.

• If $$x_i$$ is +0, the result is +0.

• If $$x_i$$ is -0, the result is -0.

• If $$x_i$$ is +infinity, the result is +1.

• If $$x_i$$ is -infinity, the result is +1.

>>> F.tanh(0)
Tensor(0.0, device=xpux:0)


Element-wise hyperbolic tangent:

>>> x = Tensor([0, 1, -1])
>>> F.tanh(x)
Tensor([ 0.      0.7616 -0.7616], device=xpux:0)