simple_linear_operators.py 10.7 KB
Newer Older
Martin Reinecke's avatar
Martin Reinecke committed
1
2
3
4
5
6
7
8
9
10
11
12
13
# 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/>.
#
14
# Copyright(C) 2013-2019 Max-Planck-Society
Martin Reinecke's avatar
Martin Reinecke committed
15
#
16
# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik.
Martin Reinecke's avatar
Martin Reinecke committed
17
18
19

from ..domain_tuple import DomainTuple
from ..domains.unstructured_domain import UnstructuredDomain
Martin Reinecke's avatar
Martin Reinecke committed
20
from ..field import Field
Philipp Arras's avatar
Philipp Arras committed
21
from ..multi_domain import MultiDomain
Martin Reinecke's avatar
Martin Reinecke committed
22
from ..multi_field import MultiField
Philipp Arras's avatar
Philipp Arras committed
23
24
from .endomorphic_operator import EndomorphicOperator
from .linear_operator import LinearOperator
Martin Reinecke's avatar
Martin Reinecke committed
25
26
27


class VdotOperator(LinearOperator):
Martin Reinecke's avatar
Martin Reinecke committed
28
29
30
31
    """Operator computing the scalar product of its input with a given Field.

    Parameters
    ----------
Philipp Arras's avatar
Philipp Arras committed
32
    field : Field or MultiField
Martin Reinecke's avatar
Martin Reinecke committed
33
34
        The field used to build the scalar product with the operator input
    """
Martin Reinecke's avatar
Martin Reinecke committed
35
36
    def __init__(self, field):
        self._field = field
Martin Reinecke's avatar
Martin Reinecke committed
37
        self._domain = field.domain
Martin Reinecke's avatar
Martin Reinecke committed
38
        self._target = DomainTuple.scalar_domain()
Martin Reinecke's avatar
Martin Reinecke committed
39
        self._capability = self.TIMES | self.ADJOINT_TIMES
Martin Reinecke's avatar
Martin Reinecke committed
40
41

    def apply(self, x, mode):
Martin Reinecke's avatar
Martin Reinecke committed
42
        self._check_mode(mode)
Martin Reinecke's avatar
Martin Reinecke committed
43
        if mode == self.TIMES:
Martin Reinecke's avatar
Martin Reinecke committed
44
            return Field.scalar(self._field.vdot(x))
Martin Reinecke's avatar
Martin Reinecke committed
45
        return self._field*x.local_data[()]
Martin Reinecke's avatar
Martin Reinecke committed
46
47


Martin Reinecke's avatar
Martin Reinecke committed
48
class ConjugationOperator(EndomorphicOperator):
49
50
51
52
53
54
55
56
    """Operator computing the complex conjugate of its input.

    Parameters
    ----------
    domain: Domain, tuple of domains or DomainTuple
        domain of the input field

    """
Martin Reinecke's avatar
Martin Reinecke committed
57
    def __init__(self, domain):
Martin Reinecke's avatar
Martin Reinecke committed
58
        self._domain = DomainTuple.make(domain)
Martin Reinecke's avatar
Martin Reinecke committed
59
        self._capability = self._all_ops
Martin Reinecke's avatar
Martin Reinecke committed
60
61
62
63
64
65

    def apply(self, x, mode):
        self._check_input(x, mode)
        return x.conjugate()


66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
class WeightApplier(EndomorphicOperator):
    """Operator multiplying its input by a given power of dvol.

    Parameters
    ----------
    domain: Domain, tuple of domains or DomainTuple
        domain of the input field
    spaces: list or tuple of int
        indices of subdomains for which the weights shall be applied
    power: int
        the power of to be used for the volume factors

    """
    def __init__(self, domain, spaces, power):
        from .. import utilities
        self._domain = DomainTuple.make(domain)
        if spaces is None:
            self._spaces = None
        else:
            self._spaces = utilities.parse_spaces(spaces, len(self._domain))
        self._power = int(power)
        self._capability = self._all_ops

    def apply(self, x, mode):
        self._check_input(x, mode)
        power = self._power if (mode & 3) else -self._power
        return x.weight(power, spaces=self._spaces)


Martin Reinecke's avatar
Martin Reinecke committed
95
class Realizer(EndomorphicOperator):
96
97
98
99
100
101
102
103
    """Operator returning the real component of its input.

    Parameters
    ----------
    domain: Domain, tuple of domains or DomainTuple
        domain of the input field

    """
Martin Reinecke's avatar
Martin Reinecke committed
104
    def __init__(self, domain):
Martin Reinecke's avatar
Martin Reinecke committed
105
        self._domain = DomainTuple.make(domain)
Martin Reinecke's avatar
Martin Reinecke committed
106
        self._capability = self.TIMES | self.ADJOINT_TIMES
Martin Reinecke's avatar
Martin Reinecke committed
107
108
109
110

    def apply(self, x, mode):
        self._check_input(x, mode)
        return x.real
Martin Reinecke's avatar
Martin Reinecke committed
111
112


113
class FieldAdapter(LinearOperator):
Martin Reinecke's avatar
Martin Reinecke committed
114
    """Operator for conversion between Fields and MultiFields.
Philipp Arras's avatar
Philipp Arras committed
115
116
117

    Parameters
    ----------
Martin Reinecke's avatar
Martin Reinecke committed
118
119
120
121
122
123
124
125
    tgt : Domain, tuple of Domain, DomainTuple, dict or MultiDomain:
        If this is a Domain, tuple of Domain or DomainTuple, this will be the
        operator's target, and its domain will be a MultiDomain consisting of
        its domain with the supplied `name`
        If this is a dict or MultiDomain, everything except for `name` will
        be stripped out of it, and the result will be the operator's target.
        Its domain will then be the DomainTuple corresponding to the single
        entry in the operator's domain.
Philipp Arras's avatar
Philipp Arras committed
126
127

    name : String
Martin Reinecke's avatar
Martin Reinecke committed
128
        The relevant key of the MultiDomain.
Philipp Arras's avatar
Philipp Arras committed
129
130
    """

Martin Reinecke's avatar
Martin Reinecke committed
131
132
133
134
135
136
137
138
139
    def __init__(self, tgt, name):
        from ..sugar import makeDomain
        tmp = makeDomain(tgt)
        if isinstance(tmp, DomainTuple):
            self._target = tmp
            self._domain = MultiDomain.make({name: tmp})
        else:
            self._domain = tmp[name]
            self._target = MultiDomain.make({name: tmp[name]})
Martin Reinecke's avatar
Martin Reinecke committed
140
        self._capability = self.TIMES | self.ADJOINT_TIMES
Martin Reinecke's avatar
Martin Reinecke committed
141
142
143

    def apply(self, x, mode):
        self._check_input(x, mode)
Martin Reinecke's avatar
Martin Reinecke committed
144
        if isinstance(x, MultiField):
Martin Reinecke's avatar
Martin Reinecke committed
145
            return x.values()[0]
Martin Reinecke's avatar
Martin Reinecke committed
146
147
148
149
        else:
            return MultiField(self._tgt(mode), (x,))

    def __repr__(self):
Martin Reinecke's avatar
Martin Reinecke committed
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
        return 'FieldAdapter'


class _SlowFieldAdapter(LinearOperator):
    """Operator for conversion between Fields and MultiFields.
    The operator is built so that the MultiDomain is always the target.
    Its domain is `tgt[name]`

    Parameters
    ----------
    dom : dict or MultiDomain:
        the operator's dom

    name : String
        The relevant key of the MultiDomain.
    """

    def __init__(self, dom, name):
        from ..sugar import makeDomain
        tmp = makeDomain(dom)
        if not isinstance(tmp, MultiDomain):
            raise TypeError("MultiDomain expected")
        self._name = str(name)
        self._domain = tmp
        self._target = tmp[name]
        self._capability = self.TIMES | self.ADJOINT_TIMES

    def apply(self, x, mode):
        self._check_input(x, mode)
        if isinstance(x, MultiField):
            return x[self._name]
        else:
Martin Reinecke's avatar
fixes    
Martin Reinecke committed
182
183
            return MultiField.from_dict({self._name: x},
                                        domain=self._tgt(mode))
Martin Reinecke's avatar
Martin Reinecke committed
184
185
186

    def __repr__(self):
        return '_SlowFieldAdapter'
Martin Reinecke's avatar
Martin Reinecke committed
187
188
189


def ducktape(left, right, name):
Martin Reinecke's avatar
Martin Reinecke committed
190
    """Convenience function creating an operator that converts between a
Martin Reinecke's avatar
Martin Reinecke committed
191
    DomainTuple and a MultiDomain.
Martin Reinecke's avatar
Martin Reinecke committed
192
193
194
195

    Parameters
    ----------
    left : None, Operator, or Domainoid
Martin Reinecke's avatar
Martin Reinecke committed
196
        Something describing the new operator's target domain.
Martin Reinecke's avatar
Martin Reinecke committed
197
198
199
        If `left` is an `Operator`, its domain is used as `left`.

    right : None, Operator, or Domainoid
Martin Reinecke's avatar
Martin Reinecke committed
200
        Something describing the new operator's input domain.
Martin Reinecke's avatar
Martin Reinecke committed
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
        If `right` is an `Operator`, its target is used as `right`.

    name : string
        The component of the `MultiDomain` that will be extracted/inserted

    Notes
    -----
    - one of the involved domains must be a `DomainTuple`, the other a
      `MultiDomain`.
    - `left` and `right` must not be both `None`, but one of them can (and
      probably should) be `None`. In this case, the missing information is
      inferred.

    Returns
    -------
Martin Reinecke's avatar
Martin Reinecke committed
216
217
218
    FieldAdapter or _SlowFieldAdapter
        an adapter operator converting between the two (possibly
        partially inferred) domains.
Martin Reinecke's avatar
Martin Reinecke committed
219
    """
Martin Reinecke's avatar
Martin Reinecke committed
220
221
    from ..sugar import makeDomain
    from .operator import Operator
222
223
224
225
226
227
228
229
    if isinstance(right, Operator):
        right = right.target
    elif right is not None:
        right = makeDomain(right)
    if isinstance(left, Operator):
        left = left.domain
    elif left is not None:
        left = makeDomain(left)
Martin Reinecke's avatar
Martin Reinecke committed
230
231
232
233
234
    if left is None:  # need to infer left from right
        if isinstance(right, MultiDomain):
            left = right[name]
        else:
            left = MultiDomain.make({name: right})
235
    elif right is None:  # need to infer right from left
Martin Reinecke's avatar
Martin Reinecke committed
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
        if isinstance(left, MultiDomain):
            right = left[name]
        else:
            right = MultiDomain.make({name: left})
    lmulti = isinstance(left, MultiDomain)
    rmulti = isinstance(right, MultiDomain)
    if lmulti+rmulti != 1:
        raise ValueError("need exactly one MultiDomain")
    if lmulti:
        if len(left) == 1:
            return FieldAdapter(left, name)
        else:
            return _SlowFieldAdapter(left, name).adjoint
    if rmulti:
        if len(right) == 1:
251
            return FieldAdapter(left, name)
Martin Reinecke's avatar
Martin Reinecke committed
252
253
254
        else:
            return _SlowFieldAdapter(right, name)
    raise ValueError("must not arrive here")
Martin Reinecke's avatar
Martin Reinecke committed
255
256
257
258
259
260
261
262
263
264


class GeometryRemover(LinearOperator):
    """Operator which transforms between a structured and an unstructured
    domain.

    Parameters
    ----------
    domain: Domain, tuple of Domain, or DomainTuple:
        the full input domain of the operator.
265
    space: int, optional
Martin Reinecke's avatar
Martin Reinecke committed
266
        The index of the subdomain on which the operator should act.
267
        If None, it acts on all spaces.
Martin Reinecke's avatar
Martin Reinecke committed
268
269
270
271
272
273
274
275

    Notes
    -----
    The operator will convert every sub-domain of its input domain to an
    UnstructuredDomain with the same shape. No weighting by volume factors
    is carried out.
    """

276
    def __init__(self, domain, space=None):
Martin Reinecke's avatar
Martin Reinecke committed
277
        self._domain = DomainTuple.make(domain)
278
279
280
281
282
283
        if space is not None:
            tgt = [dom for dom in self._domain]
            tgt[space] = UnstructuredDomain(self._domain[space].shape)
        else:
            tgt = [UnstructuredDomain(dom.shape) for dom in self._domain]
        self._target = DomainTuple.make(tgt)
Martin Reinecke's avatar
Martin Reinecke committed
284
        self._capability = self.TIMES | self.ADJOINT_TIMES
Martin Reinecke's avatar
Martin Reinecke committed
285
286
287

    def apply(self, x, mode):
        self._check_input(x, mode)
Martin Reinecke's avatar
Martin Reinecke committed
288
        return x.cast_domain(self._tgt(mode))
Martin Reinecke's avatar
Martin Reinecke committed
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305


class NullOperator(LinearOperator):
    """Operator corresponding to a matrix of all zeros.

    Parameters
    ----------
    domain : DomainTuple or MultiDomain
        input domain
    target : DomainTuple or MultiDomain
        output domain
    """

    def __init__(self, domain, target):
        from ..sugar import makeDomain
        self._domain = makeDomain(domain)
        self._target = makeDomain(target)
Martin Reinecke's avatar
Martin Reinecke committed
306
        self._capability = self.TIMES | self.ADJOINT_TIMES
Martin Reinecke's avatar
Martin Reinecke committed
307
308
309
310

    @staticmethod
    def _nullfield(dom):
        if isinstance(dom, DomainTuple):
Martin Reinecke's avatar
Martin Reinecke committed
311
            return Field(dom, 0)
Martin Reinecke's avatar
Martin Reinecke committed
312
313
314
315
316
        else:
            return MultiField.full(dom, 0)

    def apply(self, x, mode):
        self._check_input(x, mode)
Martin Reinecke's avatar
Martin Reinecke committed
317
        return self._nullfield(self._tgt(mode))
318
319
320
321
322
323
324
325
326
327


class _PartialExtractor(LinearOperator):
    def __init__(self, domain, target):
        if not isinstance(domain, MultiDomain):
            raise TypeError("MultiDomain expected")
        if not isinstance(target, MultiDomain):
            raise TypeError("MultiDomain expected")
        self._domain = domain
        self._target = target
Martin Reinecke's avatar
Martin Reinecke committed
328
329
330
        for key in self._target.keys():
            if not (self._domain[key] is not self._target[key]):
                raise ValueError("domain mismatch")
331
332
333
334
335
        self._capability = self.TIMES | self.ADJOINT_TIMES

    def apply(self, x, mode):
        self._check_input(x, mode)
        if mode == self.TIMES:
Martin Reinecke's avatar
Martin Reinecke committed
336
337
            return x.extract(self._target)
        return MultiField.from_dict({key: x[key] for key in x.domain.keys()})