from chainer import cuda
from chainer import function
from chainer import utils
from chainer.utils import type_check
class Fmod(function.Function):
@property
def label(self):
return 'fmod'
def check_type_forward(self, in_types):
type_check.expect(in_types.size() == 2)
type_check.expect(
in_types.size() == 2,
in_types[0].dtype == in_types[1].dtype,
in_types[0].dtype.kind == 'f',
in_types[1].dtype.kind == 'f',
)
def forward(self, inputs):
xp = cuda.get_array_module(*inputs)
x, divisor = inputs
m = xp.fmod(x, divisor)
return utils.force_array(m, x.dtype),
def backward(self, inputs, grad_outputs):
xp = cuda.get_array_module(*inputs)
gw, = grad_outputs
x, divisor = inputs
return gw, utils.force_array(xp.fix(x / divisor) * -1 * gw, x.dtype)
[docs]def fmod(x, divisor):
"""Elementwise mod function.
.. math::
y_i = x_i \\bmod \\mathrm{divisor}.
Args:
x (~chainer.Variable): Input variable.
divisor (~chainer.Variable): Input divisor.
Returns:
~chainer.Variable: Output variable.
"""
return Fmod()(x, divisor)