import torch
import torch.nn as nn





class LeakyReluPar(nn.Module):

    r"""LeakyRelu parametric activation
    """

    def forward(self, x, a):
        return (1.0 - a)/2.0 * torch.abs(x) + (1.0 + a)/2.0 * x

class LeakyReluParDeriv(nn.Module):
    r"""Derivative of the LeakyRelu parametric activation, wrt x.
    """

    def forward(self, x, a):
        return (1.0 - a)/2.0 * torch.sign(x.detach()) + (1.0 + a)/2.0