chainer.functions.elu¶

chainer.functions.elu(x, alpha=1.0)[source]¶

Exponential Linear Unit function.

For a parameter \(\alpha\), it is expressed as

\[\begin{split}f(x) = \left \{ \begin{array}{ll} x & {\rm if}~ x \ge 0 \\ \alpha (\exp(x) - 1) & {\rm if}~ x < 0, \end{array} \right.\end{split}\]

See: https://arxiv.org/abs/1511.07289

Parameters:	x (`Variable` or `numpy.ndarray` or `cupy.ndarray`) – Input variable. A \((s_1, s_2, ..., s_N)\)-shaped float array. alpha (float) – Parameter \(\alpha\). Default is 1.0.
Returns:	Output variable. A \((s_1, s_2, ..., s_N)\)-shaped float array.
Return type:	Variable

Example

>>> x = np.array([[-1, 0], [2, -3]], 'f')
>>> x
array([[-1.,  0.],
       [ 2., -3.]], dtype=float32)
>>> y = F.elu(x, alpha=1.)
>>> y.data
array([[-0.63212055,  0.        ],
       [ 2.        , -0.95021296]], dtype=float32)