sugar.py 9.38 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
# 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/>.
Theo Steininger's avatar
Theo Steininger committed
13
#
Martin Reinecke's avatar
Martin Reinecke committed
14
# Copyright(C) 2013-2018 Max-Planck-Society
Theo Steininger's avatar
Theo Steininger committed
15
16
17
#
# NIFTy is being developed at the Max-Planck-Institut fuer Astrophysik
# and financially supported by the Studienstiftung des deutschen Volkes.
18

19
import sys
20
import numpy as np
Martin Reinecke's avatar
Martin Reinecke committed
21
from .domains.power_space import PowerSpace
Martin Reinecke's avatar
cleanup    
Martin Reinecke committed
22
from .field import Field
Martin Reinecke's avatar
fix    
Martin Reinecke committed
23
from .multi.multi_field import MultiField
Reimar H Leike's avatar
Reimar H Leike committed
24
from .multi.block_diagonal_operator import BlockDiagonalOperator
Martin Reinecke's avatar
fix    
Martin Reinecke committed
25
from .multi.multi_domain import MultiDomain
Martin Reinecke's avatar
Martin Reinecke committed
26
from .operators.diagonal_operator import DiagonalOperator
Martin Reinecke's avatar
Martin Reinecke committed
27
from .operators.power_distributor import PowerDistributor
Martin Reinecke's avatar
Martin Reinecke committed
28
29
from .domain_tuple import DomainTuple
from . import dobj, utilities
Martin Reinecke's avatar
Martin Reinecke committed
30
from .logger import logger
31

Martin Reinecke's avatar
step 1    
Martin Reinecke committed
32
33
__all__ = ['PS_field', 'power_analyze', 'create_power_operator',
           'create_harmonic_smoothing_operator', 'from_random',
34
           'full', 'from_global_data', 'from_local_data',
Martin Reinecke's avatar
Martin Reinecke committed
35
           'makeDomain', 'sqrt', 'exp', 'log', 'tanh', 'conjugate',
Martin Reinecke's avatar
Martin Reinecke committed
36
           'get_signal_variance', 'makeOp']
37

38

39
def PS_field(pspace, func):
Martin Reinecke's avatar
Martin Reinecke committed
40
41
42
    if not isinstance(pspace, PowerSpace):
        raise TypeError
    data = dobj.from_global_data(func(pspace.k_lengths))
43
    return Field(DomainTuple.make(pspace), data)
Martin Reinecke's avatar
Martin Reinecke committed
44

Martin Reinecke's avatar
Martin Reinecke committed
45

46
47
48
49
50
51
52
53
54
55
56
57
58
def get_signal_variance(spec, space):
    """
    Computes how much a field with a given power spectrum will vary in space

    This is a small helper function that computes how the expected variance
    of a harmonically transformed sample of this power spectrum.

    Parameters
    ---------
    spec: method
        a method that takes one k-value and returns the power spectrum at that
        location
    space: PowerSpace or any harmonic Domain
Martin Reinecke's avatar
Martin Reinecke committed
59
60
61
62
        If this function is given a harmonic domain, it creates the naturally
        binned PowerSpace to that domain.
        The field, for which the signal variance is then computed, is assumed
        to have this PowerSpace as naturally binned PowerSpace
63
64
65
66
    """
    if space.harmonic:
        space = PowerSpace(space)
    if not isinstance(space, PowerSpace):
Martin Reinecke's avatar
Martin Reinecke committed
67
68
        raise ValueError(
            "space must be either a harmonic space or Power space.")
69
70
71
72
73
    field = PS_field(space, spec)
    dist = PowerDistributor(space.harmonic_partner, space)
    k_field = dist(field)
    return k_field.weight(2).sum()

74

75
76
def _single_power_analyze(field, idx, binbounds):
    power_domain = PowerSpace(field.domain[idx], binbounds)
Martin Reinecke's avatar
Martin Reinecke committed
77
78
    pd = PowerDistributor(field.domain, power_domain, idx)
    return pd.adjoint_times(field.weight(1)).weight(-1)  # divides by bin size
79
80


Martin Reinecke's avatar
Martin Reinecke committed
81
82
# MR FIXME: this function is not well suited for analyzing more than one
# subdomain at once, because it allows only one set of binbounds.
83
84
def power_analyze(field, spaces=None, binbounds=None,
                  keep_phase_information=False):
Martin Reinecke's avatar
Martin Reinecke committed
85
    """ Computes the power spectrum for a subspace of `field`.
86
87
88
89

    Creates a PowerSpace for the space addressed by `spaces` with the given
    binning and computes the power spectrum as a Field over this
    PowerSpace. This can only be done if the subspace to  be analyzed is a
Martin Reinecke's avatar
Martin Reinecke committed
90
91
    harmonic space. The resulting field has the same units as the square of the
    initial field.
92
93
94
95
96

    Parameters
    ----------
    field : Field
        The field to be analyzed
Martin Reinecke's avatar
Martin Reinecke committed
97
98
99
    spaces : None or int or tuple of int, optional
        The indices of subdomains for which the power spectrum shall be
        computed.
Martin Reinecke's avatar
Martin Reinecke committed
100
        If None, all subdomains will be converted.
101
        (default : None).
Martin Reinecke's avatar
Martin Reinecke committed
102
    binbounds : None or array-like, optional
103
        Inner bounds of the bins (default : None).
Martin Reinecke's avatar
Martin Reinecke committed
104
105
        if binbounds is None : bins are inferred.
    keep_phase_information : bool, optional
106
107
108
109
110
111
112
113
114
115
116
117
        If False, return a real-valued result containing the power spectrum
        of the input Field.
        If True, return a complex-valued result whose real component
        contains the power spectrum computed from the real part of the
        input Field, and whose imaginary component contains the power
        spectrum computed from the imaginary part of the input Field.
        The absolute value of this result should be identical to the output
        of power_analyze with keep_phase_information=False.
        (default : False).

    Returns
    -------
Martin Reinecke's avatar
Martin Reinecke committed
118
    Field
119
        The output object. Its domain is a PowerSpace and it contains
Martin Reinecke's avatar
Martin Reinecke committed
120
        the power spectrum of `field`.
121
122
123
124
    """

    for sp in field.domain:
        if not sp.harmonic and not isinstance(sp, PowerSpace):
Martin Reinecke's avatar
Martin Reinecke committed
125
126
            logger.warning("WARNING: Field has a space in `domain` which is "
                           "neither harmonic nor a PowerSpace.")
127

128
    spaces = utilities.parse_spaces(spaces, len(field.domain))
129
130
131
132

    if len(spaces) == 0:
        raise ValueError("No space for analysis specified.")

133
134
135
136
    field_real = not np.issubdtype(field.dtype, np.complexfloating)
    if (not field_real) and keep_phase_information:
        raise ValueError("cannot keep phase from real-valued input Field")

137
138
139
    if keep_phase_information:
        parts = [field.real*field.real, field.imag*field.imag]
    else:
140
141
142
143
        if field_real:
            parts = [field**2]
        else:
            parts = [field.real*field.real + field.imag*field.imag]
144
145

    for space_index in spaces:
Martin Reinecke's avatar
Martin Reinecke committed
146
        parts = [_single_power_analyze(part, space_index, binbounds)
147
148
149
150
151
                 for part in parts]

    return parts[0] + 1j*parts[1] if keep_phase_information else parts[0]


Martin Reinecke's avatar
cleanup    
Martin Reinecke committed
152
def _create_power_field(domain, power_spectrum):
Martin Reinecke's avatar
tweaks    
Martin Reinecke committed
153
154
155
156
157
158
159
160
    if not callable(power_spectrum):  # we have a Field living on a PowerSpace
        if not isinstance(power_spectrum, Field):
            raise TypeError("Field object expected")
        if len(power_spectrum.domain) != 1:
            raise ValueError("exactly one domain required")
        if not isinstance(power_spectrum.domain[0], PowerSpace):
            raise TypeError("PowerSpace required")
        power_domain = power_spectrum.domain[0]
161
        fp = power_spectrum
Martin Reinecke's avatar
tweaks    
Martin Reinecke committed
162
163
    else:
        power_domain = PowerSpace(domain)
164
        fp = PS_field(power_domain, power_spectrum)
165

Martin Reinecke's avatar
Martin Reinecke committed
166
    return PowerDistributor(domain, power_domain)(fp)
167

168

169
def create_power_operator(domain, power_spectrum, space=None):
Theo Steininger's avatar
Theo Steininger committed
170
    """ Creates a diagonal operator with the given power spectrum.
171

172
    Constructs a diagonal operator that lives over the specified domain.
173

174
175
    Parameters
    ----------
Martin Reinecke's avatar
Martin Reinecke committed
176
    domain : Domain, tuple of Domain or DomainTuple
177
        Domain over which the power operator shall live.
Martin Reinecke's avatar
Martin Reinecke committed
178
179
    power_spectrum : callable or Field
        An object that contains the power spectrum as a function of k.
Martin Reinecke's avatar
Martin Reinecke committed
180
    space : int
Martin Reinecke's avatar
Martin Reinecke committed
181
        the domain index on which the power operator will work
Theo Steininger's avatar
Theo Steininger committed
182

183
184
    Returns
    -------
Martin Reinecke's avatar
Martin Reinecke committed
185
186
    DiagonalOperator
        An operator that implements the given power spectrum.
187
    """
Martin Reinecke's avatar
Martin Reinecke committed
188
    domain = DomainTuple.make(domain)
Martin Reinecke's avatar
Martin Reinecke committed
189
    space = utilities.infer_space(domain, space)
Martin Reinecke's avatar
Martin Reinecke committed
190
191
    field = _create_power_field(domain[space], power_spectrum)
    return DiagonalOperator(field, domain, space)
192

193

194
195
196
197
def create_harmonic_smoothing_operator(domain, space, sigma):
    kfunc = domain[space].get_fft_smoothing_kernel_function(sigma)
    return DiagonalOperator(kfunc(domain[space].get_k_length_array()), domain,
                            space)
Martin Reinecke's avatar
step 1    
Martin Reinecke committed
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224


def full(domain, val):
    if isinstance(domain, (dict, MultiDomain)):
        return MultiField.full(domain, val)
    return Field.full(domain, val)


def from_random(random_type, domain, dtype=np.float64, **kwargs):
    if isinstance(domain, (dict, MultiDomain)):
        return MultiField.from_random(random_type, domain, dtype, **kwargs)
    return Field.from_random(random_type, domain, dtype, **kwargs)


def from_global_data(domain, arr, sum_up=False):
    if isinstance(domain, (dict, MultiDomain)):
        return MultiField.from_global_data(domain, arr, sum_up)
    return Field.from_global_data(domain, arr, sum_up)


def from_local_data(domain, arr):
    if isinstance(domain, (dict, MultiDomain)):
        return MultiField.from_local_data(domain, arr)
    return Field.from_local_data(domain, arr)


def makeDomain(domain):
Martin Reinecke's avatar
fixes    
Martin Reinecke committed
225
    if isinstance(domain, (MultiDomain, dict)):
Martin Reinecke's avatar
step 1    
Martin Reinecke committed
226
227
        return MultiDomain.make(domain)
    return DomainTuple.make(domain)
228
229


230
def makeOp(input):
Martin Reinecke's avatar
Martin Reinecke committed
231
232
    if input is None:
        return None
Martin Reinecke's avatar
Martin Reinecke committed
233
234
235
    if isinstance(input, Field):
        return DiagonalOperator(input)
    if isinstance(input, MultiField):
Martin Reinecke's avatar
Martin Reinecke committed
236
        return BlockDiagonalOperator(input.domain, {key: makeOp(val)
Martin Reinecke's avatar
Martin Reinecke committed
237
238
239
                                      for key, val in input.items()})
    raise NotImplementedError

240
241
# Arithmetic functions working on Fields

242

243
244
245
246
_current_module = sys.modules[__name__]

for f in ["sqrt", "exp", "log", "tanh", "conjugate"]:
    def func(f):
247
        def func2(x):
248
249
            if isinstance(x, MultiField):
                return MultiField({key: func2(val) for key, val in x.items()})
250
251
            elif isinstance(x, Field):
                fu = getattr(dobj, f)
252
                return Field(domain=x._domain, val=fu(x.val))
253
            else:
254
                return getattr(np, f)(x)
255
256
        return func2
    setattr(_current_module, f, func(f))