Coverage for python/lsst/pipe/tasks/mocks/mockObject.py: 94%

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1# 

2# LSST Data Management System 

3# Copyright 2008, 2009, 2010, 2011, 2012 LSST Corporation. 

4# 

5# This product includes software developed by the 

6# LSST Project (http://www.lsst.org/). 

7# 

8# This program is free software: you can redistribute it and/or modify 

9# it under the terms of the GNU General Public License as published by 

10# the Free Software Foundation, either version 3 of the License, or 

11# (at your option) any later version. 

12# 

13# This program is distributed in the hope that it will be useful, 

14# but WITHOUT ANY WARRANTY; without even the implied warranty of 

15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 

16# GNU General Public License for more details. 

17# 

18# You should have received a copy of the LSST License Statement and 

19# the GNU General Public License along with this program. If not, 

20# see <http://www.lsstcorp.org/LegalNotices/>. 

21# 

22import numpy 

23 

24import lsst.pex.config 

25import lsst.afw.table 

26import lsst.geom 

27import lsst.afw.image 

28import lsst.pipe.base 

29 

30 

31class MockObjectConfig(lsst.pex.config.Config): 

32 minMag = lsst.pex.config.Field(dtype=float, default=18.0, doc="Minimum magnitude for mock objects") 

33 maxMag = lsst.pex.config.Field(dtype=float, default=20.0, doc="Maximum magnitude for mock objects") 

34 maxRadius = lsst.pex.config.Field( 

35 dtype=float, default=10.0, 

36 doc=("Maximum radius of an object in arcseconds; only used " 

37 "when determining which objects are in an exposure.") 

38 ) 

39 spacing = lsst.pex.config.Field( 

40 dtype=float, default=20.0, 

41 doc="Distance between objects (in arcseconds)." 

42 ) 

43 seed = lsst.pex.config.Field(dtype=int, default=1, doc="Seed for numpy random number generator") 

44 

45 

46class MockObjectTask(lsst.pipe.base.Task): 

47 """Task that generates simple mock objects and draws them on images, intended as a subtask of 

48 MockCoaddTask. 

49 

50 May be subclassed to generate things other than stars. 

51 """ 

52 

53 ConfigClass = MockObjectConfig 

54 

55 def __init__(self, **kwds): 

56 lsst.pipe.base.Task.__init__(self, **kwds) 

57 self.schema = lsst.afw.table.SimpleTable.makeMinimalSchema() 

58 self.center = lsst.afw.table.Point2DKey.addFields(self.schema, "center", 

59 "center position in tract WCS", "pixel") 

60 self.magKey = self.schema.addField("mag", type=float, doc="exact true magnitude") 

61 self.rng = numpy.random.RandomState(self.config.seed) 

62 

63 def run(self, tractInfo, catalog=None): 

64 """Add records to the truth catalog and return it, delegating to makePositions and defineObject. 

65 

66 If the given catalog is not None, add records to this catalog and return it instead 

67 of creating a new one. 

68 

69 Subclasses should generally not need to override this method. 

70 """ 

71 if catalog is None: 71 ↛ 74line 71 didn't jump to line 74, because the condition on line 71 was never false

72 catalog = lsst.afw.table.SimpleCatalog(self.schema) 

73 else: 

74 if not catalog.getSchema().contains(self.schema): 

75 raise ValueError("Catalog schema does not match Task schema") 

76 for coord, center in self.makePositions(tractInfo): 

77 record = catalog.addNew() 

78 record.setCoord(coord) 

79 record.set(self.center, center) 

80 self.defineObject(record) 

81 return catalog 

82 

83 def makePositions(self, tractInfo): 

84 """Generate the centers (as a (coord, point) tuple) of mock objects (the point returned is 

85 in the tract coordinate system). 

86 

87 Default implementation puts objects on a grid that is square in the tract's image coordinate 

88 system, with spacing approximately given by config.spacings. 

89 

90 The return value is a Python iterable over (coord, point) pairs; the default implementation 

91 is actually an iterator (i.e. the function is a "generator"), but derived-class overrides may 

92 return any iterable. 

93 """ 

94 wcs = tractInfo.getWcs() 

95 spacing = self.config.spacing / wcs.getPixelScale().asArcseconds() # get spacing in tract pixels 

96 bbox = tractInfo.getBBox() 

97 for y in numpy.arange(bbox.getMinY() + 0.5 * spacing, bbox.getMaxY(), spacing): 

98 for x in numpy.arange(bbox.getMinX() + 0.5 * spacing, bbox.getMaxX(), spacing): 

99 yield wcs.pixelToSky(x, y), lsst.geom.Point2D(x, y), 

100 

101 def defineObject(self, record): 

102 """Fill in additional fields in a truth catalog record (id and coord will already have 

103 been set). 

104 """ 

105 mag = self.rng.rand() * (self.config.maxMag - self.config.minMag) + self.config.minMag 

106 record.setD(self.magKey, mag) 

107 

108 def drawSource(self, record, exposure, buffer=0): 

109 """Draw the given truth catalog record on the given exposure, makings use of its Psf, Wcs, 

110 PhotoCalib, and possibly filter to transform it appropriately. 

111 

112 The mask and variance planes of the Exposure are ignored. 

113 

114 The 'buffer' parameter is used to expand the source's bounding box when testing whether it 

115 is considered fully part of the image. 

116 

117 Returns 0 if the object does not appear on the given image at all, 1 if it appears partially, 

118 and 2 if it appears fully (including the given buffer). 

119 """ 

120 wcs = exposure.getWcs() 

121 center = wcs.skyToPixel(record.getCoord()) 

122 try: 

123 psfImage = exposure.getPsf().computeImage(center).convertF() 

124 except Exception: 

125 return 0 

126 psfBBox = psfImage.getBBox() 

127 overlap = exposure.getBBox() 

128 overlap.clip(psfBBox) 

129 if overlap.isEmpty(): 

130 return 0 

131 flux = exposure.getPhotoCalib().magnitudeToInstFlux(record.getD(self.magKey)) 

132 normalization = flux / psfImage.getArray().sum() 

133 if psfBBox != overlap: 

134 psfImage = psfImage.Factory(psfImage, overlap) 

135 result = 1 

136 else: 

137 result = 2 

138 if buffer != 0: 

139 bufferedBBox = lsst.geom.Box2I(psfBBox) 

140 bufferedBBox.grow(buffer) 

141 bufferedOverlap = exposure.getBBox() 

142 bufferedOverlap.clip(bufferedBBox) 

143 if bufferedOverlap != bufferedBBox: 

144 result = 1 

145 image = exposure.getMaskedImage().getImage() 

146 subImage = image.Factory(image, overlap) 

147 subImage.scaledPlus(normalization, psfImage) 

148 return result