Source code for nifty8.operators.endomorphic_operator
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# Copyright(C) 2013-2020 Max-Planck-Society
#
# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik.
from .linear_operator import LinearOperator
[docs]
class EndomorphicOperator(LinearOperator):
"""Represents a :class:`LinearOperator` which is endomorphic, i.e. one
which has identical domain and target.
"""
@property
def target(self):
"""DomainTuple : returns :attr:`domain`
Returns `self.domain`, because this is also the target domain
for endomorphic operators."""
return self._domain
[docs]
def draw_sample(self, from_inverse=False):
"""Generates a sample from a Gaussian distribution with zero mean and
covariance given by the operator.
May or may not be implemented. Only optional.
Parameters
----------
from_inverse : bool (default : False)
if True, the sample is drawn from the inverse of the operator
Returns
-------
:class:`nifty8.field.Field` or :class:`nifty8.multi_field.MultiField`
A sample from the Gaussian of given covariance.
"""
raise NotImplementedError
@property
def sampling_dtype(self):
"""Sampling dtype if operator is used as covariance operator."""
if hasattr(self, "_dtype"):
return self._dtype
return None
[docs]
def get_sqrt(self):
"""Return operator op which obeys `self == op.adjoint @ op`.
Note that this function is only implemented for operators with real
spectrum.
Returns
-------
EndomorphicOperator
Operator which is the square root of `self`
"""
raise NotImplementedError
def _dom(self, mode):
return self._domain
def _tgt(self, mode):
return self._domain
def _check_input(self, x, mode):
self._check_mode(mode)
if self.domain != x.domain:
raise ValueError("The operator's and field's domains don't match.")