Coverage for python/lsst/obs/base/utils.py : 20%

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1# This file is part of obs_base.
2#
3# Developed for the LSST Data Management System.
4# This product includes software developed by the LSST Project
5# (https://www.lsst.org).
6# See the COPYRIGHT file at the top-level directory of this distribution
7# for details of code ownership.
8#
9# This program is free software: you can redistribute it and/or modify
10# it under the terms of the GNU General Public License as published by
11# the Free Software Foundation, either version 3 of the License, or
12# (at your option) any later version.
13#
14# This program is distributed in the hope that it will be useful,
15# but WITHOUT ANY WARRANTY; without even the implied warranty of
16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17# GNU General Public License for more details.
18#
19# You should have received a copy of the GNU General Public License
20# along with this program. If not, see <https://www.gnu.org/licenses/>.
22__all__ = ('InitialSkyWcsError', 'createInitialSkyWcs', 'bboxFromIraf')
24import re
25import lsst.geom as geom
27from . import Instrument
28from lsst.afw.cameraGeom import PIXELS, FIELD_ANGLE
29from lsst.afw.image import RotType
30from lsst.afw.geom.skyWcs import makeSkyWcs
31import lsst.pex.exceptions
32from lsst.utils import doImport
35class InitialSkyWcsError(Exception):
36 """For handling failures when creating a SkyWcs from a camera geometry and
37 boresight.
39 Typically used as a chained exception from a lower level exception.
40 """
41 pass
44def createInitialSkyWcs(visitInfo, detector, flipX=False):
45 """Create a SkyWcs from the telescope boresight and detector geometry.
47 A typical usecase for this is to create the initial WCS for a newly-read
48 raw exposure.
51 Parameters
52 ----------
53 visitInfo : `lsst.afw.image.VisitInfo`
54 Where to get the telescope boresight and rotator angle from.
55 detector : `lsst.afw.cameraGeom.Detector`
56 Where to get the camera geomtry from.
57 flipX : `bool`, optional
58 If False, +X is along W, if True +X is along E.
60 Returns
61 -------
62 skyWcs : `lsst.afw.geom.SkyWcs`
63 The new composed WCS.
65 Raises
66 ------
67 InitialSkyWcsError
68 Raised if there is an error generating the SkyWcs, chained from the
69 lower-level exception if available.
70 """
71 if visitInfo.getRotType() != RotType.SKY:
72 msg = (f"Cannot create SkyWcs from camera geometry: rotator angle defined using "
73 f"RotType={visitInfo.getRotType()} instead of SKY.")
74 raise InitialSkyWcsError(msg)
75 orientation = visitInfo.getBoresightRotAngle()
76 boresight = visitInfo.getBoresightRaDec()
77 try:
78 pixelsToFieldAngle = detector.getTransform(detector.makeCameraSys(PIXELS),
79 detector.makeCameraSys(FIELD_ANGLE))
80 except lsst.pex.exceptions.InvalidParameterError as e:
81 raise InitialSkyWcsError("Cannot compute PIXELS to FIELD_ANGLE Transform.") from e
82 return makeSkyWcs(pixelsToFieldAngle, orientation, flipX, boresight)
85def bboxFromIraf(irafBBoxStr):
86 """Return a Box2I corresponding to an IRAF-style BBOX
88 [x0:x1,y0:y1] where x0 and x1 are the one-indexed start and end columns, and correspondingly
89 y0 and y1 are the start and end rows.
90 """
92 mat = re.search(r"^\[([-\d]+):([-\d]+),([-\d]+):([-\d]+)\]$", irafBBoxStr)
93 if not mat:
94 raise RuntimeError("Unable to parse IRAF-style bbox \"%s\"" % irafBBoxStr)
95 x0, x1, y0, y1 = [int(_) for _ in mat.groups()]
97 return geom.BoxI(geom.PointI(x0 - 1, y0 - 1), geom.PointI(x1 - 1, y1 - 1))
100def getInstrument(instrumentName, registry=None):
101 """Return an instance of a named instrument.
103 If the instrument name not is qualified (does not contain a '.') and a
104 butler registry is provided, this will attempt to load the instrument using
105 Instrument.fromName. Otherwise the instrument will be imported and
106 instantiated.
108 Parameters
109 ----------
110 instrumentName : string
111 The name or fully-qualified class name of an instrument.
112 registry : `lsst.daf.butler.Registry`, optional
113 Butler registry to query to find information about the instrument, by
114 default None
116 Returns
117 -------
118 Instrument subclass instance
119 The instantiated instrument.
121 Raises
122 ------
123 RuntimeError
124 If the instrument can not be imported, instantiated, or obtained from
125 the registry.
126 TypeError
127 If the instrument is not a subclass of lsst.obs.base.Instrument.
128 """
129 if "." not in instrumentName and registry is not None:
130 try:
131 instr = Instrument.fromName(instrumentName, registry)
132 except Exception as err:
133 raise RuntimeError(
134 f"Could not get instrument from name: {instrumentName}. Failed with exception: {err}")
135 else:
136 try:
137 instr = doImport(instrumentName)
138 except Exception as err:
139 raise RuntimeError(f"Could not import instrument: {instrumentName}. Failed with exception: {err}")
140 instr = instr()
141 if not isinstance(instr, Instrument):
142 raise TypeError(f"{instrumentName} is not an Instrument subclass.")
143 return instr
146# TODO remove the impl in pipe_base? (NB this combines setDottedAtr AND the
147# handling in ConfigValueAction.__call__)
148def setDottedAttr(item, name, value):
149 """Set an instance attribute (like `setattr` but accepting hierarchical
150 names such as ``foo.bar.baz``) If the attribute can not be set as a string,
151 will attempt to set the attribute with the result of eval'ing the value.
153 Parameters
154 ----------
155 item : obj
156 Object whose attribute is to be set.
157 name : `str`
158 Name of attribute to set.
159 value : obj
160 New value for the attribute.
162 Notes
163 -----
164 For example if name is ``foo.bar.baz`` then ``item.foo.bar.baz``
165 is set to the specified value.
167 Raises
168 ------
169 AttributeError
170 If the item does not have a field specified by name that can be set.
171 RuntimeError
172 If the value can not be set as a string or rendered by eval, or if
173 there is an error setting the attribute with the rendered value.
174 """
175 subitem = item
176 subnameList = name.split(".")
177 for subname in subnameList[:-1]:
178 subitem = getattr(subitem, subname)
179 try:
180 setattr(subitem, subnameList[-1], value)
181 except AttributeError:
182 raise AttributeError(f"No field: {name!r}")
183 except Exception:
184 try:
185 v = eval(value, {})
186 except Exception:
187 raise RuntimeError(f"Cannot render {value!r} as a value for {name!r}")
188 try:
189 setattr(subitem, subnameList[-1], v)
190 except Exception as e:
191 raise RuntimeError(f"Cannot set config. {name}={value!r}: {e}")
194def setDottedAttrs(item, attrs):
195 for name, value in attrs:
196 setDottedAttr(item, name, value)