# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see .
#
# Copyright(C) 2013-2018 Max-Planck-Society
#
# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
# and financially supported by the Studienstiftung des deutschen Volkes.
from __future__ import absolute_import, division, print_function
from numpy import inf, isnan
from ..compat import *
from ..operators.operator import Operator
from ..operators.sandwich_operator import SandwichOperator
from ..sugar import makeOp
from ..linearization import Linearization
class PoissonianEnergy(Operator):
def __init__(self, op, d):
super(PoissonianEnergy, self).__init__()
self._op = op
self._d = d
@property
def domain(self):
return self._op.domain
@property
def target(self):
return DomainTuple.scalar_domain()
def __call__(self, x):
x = self._op(x)
res = (x - self._d*x.log()).sum()
if not isinstance(x, Linearization):
return res
metric = SandwichOperator.make(x.jac, makeOp(1./x.val))
return res.add_metric(metric)