1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
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
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
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
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
# -*- coding: utf-8 -*-
# Licensed under a 3-clause BSD style license - see LICENSE.rst
from __future__ import (absolute_import, division, print_function,
unicode_literals)
import numpy as np
from ... import units as u
from .. import transformations as t
from ..builtin_frames import ICRS, FK5, FK4, FK4NoETerms, Galactic
from .. import representation as r
from ..baseframe import frame_transform_graph
from ...tests.helper import assert_quantity_allclose as assert_allclose
from ...time import Time
#Coordinates just for these tests.
class TCoo1(ICRS):
pass
class TCoo2(ICRS):
pass
def test_transform_classes():
"""
Tests the class-based/OO syntax for creating transforms
"""
tfun = lambda c, f: f.__class__(ra=c.ra, dec=c.dec)
trans1 = t.FunctionTransform(tfun, TCoo1, TCoo2,
register_graph=frame_transform_graph)
c1 = TCoo1(ra=1*u.radian, dec=0.5*u.radian)
c2 = c1.transform_to(TCoo2)
assert_allclose(c2.ra.radian, 1)
assert_allclose(c2.dec.radian, 0.5)
def matfunc(coo, fr):
return [[1, 0, 0],
[0, coo.ra.degree, 0],
[0, 0, 1]]
trans2 = t.DynamicMatrixTransform(matfunc, TCoo1, TCoo2)
trans2.register(frame_transform_graph)
c3 = TCoo1(ra=1*u.deg, dec=2*u.deg)
c4 = c3.transform_to(TCoo2)
assert_allclose(c4.ra.degree, 1)
assert_allclose(c4.ra.degree, 1)
# be sure to unregister the second one - no need for trans1 because it
# already got unregistered when trans2 was created.
trans2.unregister(frame_transform_graph)
def test_transform_decos():
"""
Tests the decorator syntax for creating transforms
"""
c1 = TCoo1(ra=1*u.deg, dec=2*u.deg)
@frame_transform_graph.transform(t.FunctionTransform, TCoo1, TCoo2)
def trans(coo1, f):
return TCoo2(ra=coo1.ra, dec=coo1.dec * 2)
c2 = c1.transform_to(TCoo2)
assert_allclose(c2.ra.degree, 1)
assert_allclose(c2.dec.degree, 4)
c3 = TCoo1(r.CartesianRepresentation(x=1*u.pc, y=1*u.pc, z=2*u.pc))
@frame_transform_graph.transform(t.StaticMatrixTransform, TCoo1, TCoo2)
def matrix():
return [[2, 0, 0],
[0, 1, 0],
[0, 0, 1]]
c4 = c3.transform_to(TCoo2)
assert_allclose(c4.cartesian.x, 2*u.pc)
assert_allclose(c4.cartesian.y, 1*u.pc)
assert_allclose(c4.cartesian.z, 2*u.pc)
def test_shortest_path():
class FakeTransform(object):
def __init__(self, pri):
self.priority = pri
g = t.TransformGraph()
#cheating by adding graph elements directly that are not classes - the
#graphing algorithm still works fine with integers - it just isn't a valid
#TransformGraph
#the graph looks is a down-going diamond graph with the lower-right slightly
#heavier and a cycle from the bottom to the top
#also, a pair of nodes isolated from 1
g._graph[1][2] = FakeTransform(1)
g._graph[1][3] = FakeTransform(1)
g._graph[2][4] = FakeTransform(1)
g._graph[3][4] = FakeTransform(2)
g._graph[4][1] = FakeTransform(5)
g._graph[5][6] = FakeTransform(1)
path, d = g.find_shortest_path(1, 2)
assert path == [1, 2]
assert d == 1
path, d = g.find_shortest_path(1, 3)
assert path == [1, 3]
assert d == 1
path, d = g.find_shortest_path(1, 4)
print('Cached paths:', g._shortestpaths)
assert path == [1, 2, 4]
assert d == 2
#unreachable
path, d = g.find_shortest_path(1, 5)
assert path is None
assert d == float('inf')
path, d = g.find_shortest_path(5, 6)
assert path == [5, 6]
assert d == 1
def test_sphere_cart():
"""
Tests the spherical <-> cartesian transform functions
"""
from ...utils import NumpyRNGContext
from .. import spherical_to_cartesian, cartesian_to_spherical
x, y, z = spherical_to_cartesian(1, 0, 0)
assert_allclose(x, 1)
assert_allclose(y, 0)
assert_allclose(z, 0)
x, y, z = spherical_to_cartesian(0, 1, 1)
assert_allclose(x, 0)
assert_allclose(y, 0)
assert_allclose(z, 0)
x, y, z = spherical_to_cartesian(5, 0, np.arcsin(4. / 5.))
assert_allclose(x, 3)
assert_allclose(y, 4)
assert_allclose(z, 0)
r, lat, lon = cartesian_to_spherical(0, 1, 0)
assert_allclose(r, 1)
assert_allclose(lat, 0 * u.deg)
assert_allclose(lon, np.pi / 2 * u.rad)
#test round-tripping
with NumpyRNGContext(13579):
x, y, z = np.random.randn(3, 5)
r, lat, lon = cartesian_to_spherical(x, y, z)
x2, y2, z2 = spherical_to_cartesian(r, lat, lon)
assert_allclose(x, x2)
assert_allclose(y, y2)
assert_allclose(z, z2)
def test_transform_path_pri():
"""
This checks that the transformation path prioritization works by
making sure the ICRS -> Gal transformation always goes through FK5
and not FK4.
"""
frame_transform_graph.invalidate_cache()
tpath, td = frame_transform_graph.find_shortest_path(ICRS, Galactic)
assert tpath == [ICRS, FK5, Galactic]
assert td == 2
#but direct from FK4 to Galactic should still be possible
tpath, td = frame_transform_graph.find_shortest_path(FK4, Galactic)
assert tpath == [FK4, FK4NoETerms, Galactic]
assert td == 2
def test_obstime():
"""
Checks to make sure observation time is
accounted for at least in FK4 <-> ICRS transformations
"""
b1950 = Time('B1950', scale='utc')
j1975 = Time('J1975', scale='utc')
fk4_50 = FK4(ra=1*u.deg, dec=2*u.deg, obstime=b1950)
fk4_75 = FK4(ra=1*u.deg, dec=2*u.deg, obstime=j1975)
icrs_50 = fk4_50.transform_to(ICRS)
icrs_75 = fk4_75.transform_to(ICRS)
# now check that the resulting coordinates are *different* - they should be,
# because the obstime is different
assert icrs_50.ra.degree != icrs_75.ra.degree
assert icrs_50.dec.degree != icrs_75.dec.degree
|
