sparse_sigmoid

Contents

sparse_sigmoid#

class brainstate.nn.sparse_sigmoid(x)[source]#

Sparse sigmoid activation function.

Computes the function:

\[\begin{split}\mathrm{sparse\_sigmoid}(x) = \begin{cases} 0, & x \leq -1\\ \frac{1}{2}(x+1), & -1 < x < 1 \\ 1, & 1 \leq x \end{cases}\end{split}\]

This is the twin function of the standard sigmoid activation, ensuring a zero output for inputs less than -1, a 1 output for inputs greater than 1, and a linear output for inputs between -1 and 1. It is the derivative of sparse_plus.

Parameters:: x (Array | ndarray | bool | number | bool | int | float | complex | Quantity) – Input array.
Returns:: An array with the same shape as the input.
Return type:: Array | Quantity

See also

sigmoid: Standard sigmoid activation function.
sparse_plus: Sparse plus activation function.

References