class_docstr: Exponential Linear Unit gradient function.
class_docstr_tok: ["Exponential","Linear","Unit","gradient","function","."]
code: def backward(self, indexes, grad_outputs):
      (ggx,) = grad_outputs
      gy2 = ggx * (self.cond <= 0)
      return (gy2,)
  
file_path: chainer/chainer/functions/activation/elu.py
imports: import numpy
  from chainer.backends import cuda
  from chainer import function_node
  from chainer import utils
  from chainer.utils import type_check
label_desc: Use image node_id 4 for calling the ELUGrad obj's underlying member method code with example usage: obj.backward(indexes, grad_outputs) and returns: gy2