simple_linear_operators.py 12.1 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
25
from .. import utilities
Martin Reinecke's avatar
Martin Reinecke committed
26
27
28


class VdotOperator(LinearOperator):
Martin Reinecke's avatar
Martin Reinecke committed
29
30
31
32
    """Operator computing the scalar product of its input with a given Field.

    Parameters
    ----------
Philipp Arras's avatar
Philipp Arras committed
33
    field : Field or MultiField
Martin Reinecke's avatar
Martin Reinecke committed
34
35
        The field used to build the scalar product with the operator input
    """
Martin Reinecke's avatar
Martin Reinecke committed
36
37
    def __init__(self, field):
        self._field = field
Martin Reinecke's avatar
Martin Reinecke committed
38
        self._domain = field.domain
Martin Reinecke's avatar
Martin Reinecke committed
39
        self._target = DomainTuple.scalar_domain()
Martin Reinecke's avatar
Martin Reinecke committed
40
        self._capability = self.TIMES | self.ADJOINT_TIMES
Martin Reinecke's avatar
Martin Reinecke committed
41
42

    def apply(self, x, mode):
Martin Reinecke's avatar
Martin Reinecke committed
43
        self._check_mode(mode)
Martin Reinecke's avatar
Martin Reinecke committed
44
        if mode == self.TIMES:
Martin Reinecke's avatar
Martin Reinecke committed
45
            return Field.scalar(self._field.vdot(x))
Martin Reinecke's avatar
Martin Reinecke committed
46
        return self._field*x.local_data[()]
Martin Reinecke's avatar
Martin Reinecke committed
47
48


Martin Reinecke's avatar
Martin Reinecke committed
49
class ConjugationOperator(EndomorphicOperator):
50
51
52
53
54
55
56
57
    """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
58
    def __init__(self, domain):
Martin Reinecke's avatar
Martin Reinecke committed
59
        self._domain = DomainTuple.make(domain)
Martin Reinecke's avatar
Martin Reinecke committed
60
        self._capability = self._all_ops
Martin Reinecke's avatar
Martin Reinecke committed
61
62
63
64
65
66

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


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
95
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
96
class Realizer(EndomorphicOperator):
97
98
99
100
101
102
103
104
    """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
105
    def __init__(self, domain):
Martin Reinecke's avatar
Martin Reinecke committed
106
        self._domain = DomainTuple.make(domain)
Martin Reinecke's avatar
Martin Reinecke committed
107
        self._capability = self.TIMES | self.ADJOINT_TIMES
Martin Reinecke's avatar
Martin Reinecke committed
108
109
110
111

    def apply(self, x, mode):
        self._check_input(x, mode)
        return x.real
Martin Reinecke's avatar
Martin Reinecke committed
112
113


114
class FieldAdapter(LinearOperator):
Martin Reinecke's avatar
Martin Reinecke committed
115
    """Operator for conversion between Fields and MultiFields.
Philipp Arras's avatar
Philipp Arras committed
116
117
118

    Parameters
    ----------
Martin Reinecke's avatar
Martin Reinecke committed
119
120
121
122
123
124
125
126
    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
127
128

    name : String
Martin Reinecke's avatar
Martin Reinecke committed
129
        The relevant key of the MultiDomain.
Philipp Arras's avatar
Philipp Arras committed
130
131
    """

Martin Reinecke's avatar
Martin Reinecke committed
132
133
134
135
136
137
138
139
140
    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
141
        self._capability = self.TIMES | self.ADJOINT_TIMES
Martin Reinecke's avatar
Martin Reinecke committed
142
143
144

    def apply(self, x, mode):
        self._check_input(x, mode)
Martin Reinecke's avatar
Martin Reinecke committed
145
        if isinstance(x, MultiField):
Martin Reinecke's avatar
Martin Reinecke committed
146
            return x.values()[0]
Martin Reinecke's avatar
Martin Reinecke committed
147
148
149
150
        else:
            return MultiField(self._tgt(mode), (x,))

    def __repr__(self):
151
152
153
154
155
156
157
158
159
160
        s = 'FieldAdapter'
        dom = isinstance(self._domain, MultiDomain)
        tgt = isinstance(self._target, MultiDomain)
        if dom and tgt:
            s += ' {} <- {}'.format(self._target.keys(), self._domain.keys())
        elif dom:
            s += ' <- {}'.format(self._domain.keys())
        elif tgt:
            s += ' {} <-'.format(self._target.keys())
        return s
Martin Reinecke's avatar
Martin Reinecke committed
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191


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
192
193
            return MultiField.from_dict({self._name: x},
                                        domain=self._tgt(mode))
Martin Reinecke's avatar
Martin Reinecke committed
194
195
196

    def __repr__(self):
        return '_SlowFieldAdapter'
Martin Reinecke's avatar
Martin Reinecke committed
197
198
199


def ducktape(left, right, name):
Martin Reinecke's avatar
Martin Reinecke committed
200
    """Convenience function creating an operator that converts between a
Martin Reinecke's avatar
Martin Reinecke committed
201
    DomainTuple and a MultiDomain.
Martin Reinecke's avatar
Martin Reinecke committed
202
203
204
205

    Parameters
    ----------
    left : None, Operator, or Domainoid
Martin Reinecke's avatar
Martin Reinecke committed
206
        Something describing the new operator's target domain.
Martin Reinecke's avatar
Martin Reinecke committed
207
208
209
        If `left` is an `Operator`, its domain is used as `left`.

    right : None, Operator, or Domainoid
Martin Reinecke's avatar
Martin Reinecke committed
210
        Something describing the new operator's input domain.
Martin Reinecke's avatar
Martin Reinecke committed
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
        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
226
227
228
    FieldAdapter or _SlowFieldAdapter
        an adapter operator converting between the two (possibly
        partially inferred) domains.
Martin Reinecke's avatar
Martin Reinecke committed
229
    """
Martin Reinecke's avatar
Martin Reinecke committed
230
231
    from ..sugar import makeDomain
    from .operator import Operator
232
233
234
235
236
237
238
239
    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
240
241
242
243
244
    if left is None:  # need to infer left from right
        if isinstance(right, MultiDomain):
            left = right[name]
        else:
            left = MultiDomain.make({name: right})
245
    elif right is None:  # need to infer right from left
Martin Reinecke's avatar
Martin Reinecke committed
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
        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:
261
            return FieldAdapter(left, name)
Martin Reinecke's avatar
Martin Reinecke committed
262
263
264
        else:
            return _SlowFieldAdapter(right, name)
    raise ValueError("must not arrive here")
Martin Reinecke's avatar
Martin Reinecke committed
265
266
267
268
269
270
271
272
273
274


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.
275
    space: int, optional
Martin Reinecke's avatar
Martin Reinecke committed
276
        The index of the subdomain on which the operator should act.
277
        If None, it acts on all spaces.
Martin Reinecke's avatar
Martin Reinecke committed
278
279
280
281
282
283
284
285

    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.
    """

286
    def __init__(self, domain, space=None):
Martin Reinecke's avatar
Martin Reinecke committed
287
        self._domain = DomainTuple.make(domain)
288
289
290
291
292
293
        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
294
        self._capability = self.TIMES | self.ADJOINT_TIMES
Martin Reinecke's avatar
Martin Reinecke committed
295
296
297

    def apply(self, x, mode):
        self._check_input(x, mode)
Martin Reinecke's avatar
Martin Reinecke committed
298
        return x.cast_domain(self._tgt(mode))
Martin Reinecke's avatar
Martin Reinecke committed
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315


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
316
        self._capability = self.TIMES | self.ADJOINT_TIMES
Martin Reinecke's avatar
Martin Reinecke committed
317
318
319
320

    @staticmethod
    def _nullfield(dom):
        if isinstance(dom, DomainTuple):
Martin Reinecke's avatar
Martin Reinecke committed
321
            return Field(dom, 0)
Martin Reinecke's avatar
Martin Reinecke committed
322
323
324
325
326
        else:
            return MultiField.full(dom, 0)

    def apply(self, x, mode):
        self._check_input(x, mode)
Martin Reinecke's avatar
Martin Reinecke committed
327
        return self._nullfield(self._tgt(mode))
328
329
330
331
332
333
334
335
336
337


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
338
339
340
        for key in self._target.keys():
            if not (self._domain[key] is not self._target[key]):
                raise ValueError("domain mismatch")
341
342
343
344
345
        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
346
347
            return x.extract(self._target)
        return MultiField.from_dict({key: x[key] for key in x.domain.keys()})
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380


class MatrixProductOperator(EndomorphicOperator):
    """Endomorphic matrix multiplication with input field.

    Parameters
    ----------
    domain: DomainTuple
        Domain of the operator.
    matrix:
        Matrix of shape (field.shape, field.shape)
    space: int, optional
        The index of the subdomain on which the operator should act
    """
    def __init__(self, domain, matrix, space=None):
        self._domain = DomainTuple.make(domain)
        self._capability = self.TIMES | self.ADJOINT_TIMES
        self._space = utilities.infer_space(self._domain, space)

        self._mat = matrix
        self._mat_tr = matrix.transpose()

    def apply(self, x, mode):
        self._check_input(x, mode)
        res = x.to_global_data()
        if mode == self.TIMES:
            res = self._mat.dot(res)
        if mode == self.ADJOINT_TIMES:
            res = self._mat_tr.dot(res)
        return Field.from_global_data(self._domain, res)

    def __repr__(self):
        return "MatrixProductOperator"