# mars.tensor.tanh¶

mars.tensor.tanh(x, out=None, where=None, **kwargs)[source]

Compute hyperbolic tangent element-wise.

Equivalent to `mt.sinh(x)/np.cosh(x)` or `-1j * mt.tan(1j*x)`.

Parameters
• x (array_like) – Input tensor.

• out (Tensor, None, or tuple of Tensor and None, optional) – A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or None, a freshly-allocated tensor is returned. A tuple (possible only as a keyword argument) must have length equal to the number of outputs.

• where (array_like, optional) – Values of True indicate to calculate the ufunc at that position, values of False indicate to leave the value in the output alone.

• **kwargs

Returns

y – The corresponding hyperbolic tangent values.

Return type

Tensor

Notes

If out is provided, the function writes the result into it, and returns a reference to out. (See Examples)

References

1

M. Abramowitz and I. A. Stegun, Handbook of Mathematical Functions. New York, NY: Dover, 1972, pg. 83. http://www.math.sfu.ca/~cbm/aands/

2

Wikipedia, “Hyperbolic function”, http://en.wikipedia.org/wiki/Hyperbolic_function

Examples

```>>> import mars.tensor as mt
```
```>>> mt.tanh((0, mt.pi*1j, mt.pi*1j/2)).execute()
array([ 0. +0.00000000e+00j,  0. -1.22460635e-16j,  0. +1.63317787e+16j])
```
```>>> # Example of providing the optional output parameter illustrating
>>> # that what is returned is a reference to said parameter
>>> out1 = mt.zeros(1)
>>> out2 = mt.tanh([0.1], out1)
>>> out2 is out1
True
```
```>>> # Example of ValueError due to provision of shape mis-matched `out`
>>> mt.tanh(mt.zeros((3,3)),mt.zeros((2,2)))
Traceback (most recent call last):
...
ValueError: operands could not be broadcast together with shapes (3,3) (2,2)
```