wiener_filter_curvature.py 2.24 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
# 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 <http://www.gnu.org/licenses/>.
#
# 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.

19 20
from __future__ import absolute_import, division, print_function
from ..compat import *
Martin Reinecke's avatar
Martin Reinecke committed
21
from ..operators.sandwich_operator import SandwichOperator
Martin Reinecke's avatar
Martin Reinecke committed
22
from ..operators.inversion_enabler import InversionEnabler
23
from ..operators.sampling_enabler import SamplingEnabler
24

Martin Reinecke's avatar
PEP8  
Martin Reinecke committed
25

26 27
def WienerFilterCurvature(R, N, S, iteration_controller=None,
                          iteration_controller_sampling=None):
Jakob Knollmueller's avatar
Jakob Knollmueller committed
28 29 30 31
    """The curvature of the WienerFilterEnergy.

    This operator implements the second derivative of the
    WienerFilterEnergy used in some minimization algorithms or
32 33
    for error estimates of the posterior maps. It is the
    inverse of the propagator operator.
Jakob Knollmueller's avatar
Jakob Knollmueller committed
34 35 36

    Parameters
    ----------
Martin Reinecke's avatar
Martin Reinecke committed
37
    R : LinearOperator
Martin Reinecke's avatar
Martin Reinecke committed
38
        The response operator of the Wiener filter measurement.
Martin Reinecke's avatar
Martin Reinecke committed
39
    N : EndomorphicOperator
Martin Reinecke's avatar
Martin Reinecke committed
40
        The noise covariance.
Martin Reinecke's avatar
Martin Reinecke committed
41
    S : DiagonalOperator
Martin Reinecke's avatar
Martin Reinecke committed
42
        The prior signal covariance
43 44 45 46 47
    iteration_controller : IterationController
        The iteration controller to use during numerical inversion via
        ConjugateGradient.
    iteration_controller_sampling : IterationController
        The iteration controller to use for sampling.
Jakob Knollmueller's avatar
Jakob Knollmueller committed
48
    """
49
    M = SandwichOperator.make(R, N.inverse)
50
    if iteration_controller_sampling is not None:
51 52
        op = SamplingEnabler(M, S.inverse, iteration_controller_sampling,
                             S.inverse)
53 54
    else:
        op = M + S.inverse
55
    return InversionEnabler(op, iteration_controller, S.inverse)