lsst.pipe.tasks g4a6547c0d5+6fab381471
exampleCmdLineTask.py
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21
22import lsst.afw.display as afwDisplay
23import lsst.pex.config as pexConfig
24import lsst.pipe.base as pipeBase
25from .exampleStatsTasks import ExampleSigmaClippedStatsTask
26
27__all__ = ["ExampleCmdLineConfig", "ExampleCmdLineTask"]
28
29# The following block adds links to this task from the Task Documentation page.
30# This works even for task(s) that are not in lsst.pipe.tasks.
31
37
38
39class ExampleCmdLineConfig(pexConfig.Config):
40 """!Configuration for ExampleCmdLineTask
41 """
42 stats = pexConfig.ConfigurableField(
43 doc="Subtask to compute statistics of an image",
44 target=ExampleSigmaClippedStatsTask,
45 )
46 doFail = pexConfig.Field(
47 doc="Raise an lsst.base.TaskError exception when processing each image? "
48 "This allows one to see the effects of the --doraise command line flag",
49 dtype=bool,
50 default=False,
51 )
52
53
54class ExampleCmdLineTask(pipeBase.CmdLineTask):
55 r"""!Example command-line task that computes simple statistics on an image
56
57 \section pipeTasks_ExampleCmdLineTask_Contents Contents
58
59 - \ref pipeTasks_ExampleCmdLineTask_Purpose
60 - \ref pipeTasks_ExampleCmdLineTask_Config
61 - \ref pipeTasks_ExampleCmdLineTask_Debug
62 - \ref pipeTasks_ExampleCmdLineTask_Example
63
64 \section pipeTasks_ExampleCmdLineTask_Purpose Description
65
66 \copybrief ExampleCmdLineTask
67
68 This task was written as an example for the documents \ref pipeTasks_writeTask
69 and \ref pipeTasks_writeCmdLineTask.
70 The task reads in a "calexp" (a calibrated science \ref lsst::afw::image::Exposure "exposure"),
71 computes statistics on the image plane, and logs and returns the statistics.
72 In addition, if debugging is enabled, it displays the image in current display backend.
73
74 The image statistics are computed using a subtask, in order to show how to call subtasks and how to
75 \ref pipeBase_argumentParser_retargetSubtasks "retarget" (replace) them with variant subtasks.
76
77 The main method is \ref ExampleCmdLineTask.runDataRef "runDataRef".
78
79 \section pipeTasks_ExampleCmdLineTask_Config Configuration parameters
80
81 See \ref ExampleCmdLineConfig
82
83 \section pipeTasks_ExampleCmdLineTask_Debug Debug variables
84
85 This task supports the following debug variables:
86 <dl>
87 <dt>`display`
88 <dd>If True then display the exposure in current display backend
89 </dl>
90
91 To enable debugging, see \ref baseDebug.
92
93 \section pipeTasks_ExampleCmdLineTask_Example A complete example of using ExampleCmdLineTask
94
95 This code is in examples/exampleCmdLineTask.py, and can be run as follows:
96 \code
97 examples/exampleCmdLineTask.py $OBS_TEST_DIR/data/input --id
98 # that will process all data; you can also try any combination of these flags:
99 --id filter=g
100 --config doFail=True --doraise
101 --show config data
102 \endcode
103 """
104 ConfigClass = ExampleCmdLineConfig
105 _DefaultName = "exampleTask"
106
107 def __init__(self, *args, **kwargs):
108 """Construct an ExampleCmdLineTask
109
110 Call the parent class constructor and make the "stats" subtask from the config field of the same name.
111 """
112 pipeBase.CmdLineTask.__init__(self, *args, **kwargs)
113 self.makeSubtask("stats")
114
115 @pipeBase.timeMethod
116 def runDataRef(self, dataRef):
117 """!Compute a few statistics on the image plane of an exposure
118
119 @param dataRef: data reference for a calibrated science exposure ("calexp")
120 @return a pipeBase Struct containing:
121 - mean: mean of image plane
122 - meanErr: uncertainty in mean
123 - stdDev: standard deviation of image plane
124 - stdDevErr: uncertainty in standard deviation
125 """
126 self.log.info("Processing data ID %s", dataRef.dataId)
127 if self.config.doFail:
128 raise pipeBase.TaskError("Raising TaskError by request (config.doFail=True)")
129
130 # Unpersist the raw exposure pointed to by the data reference
131 rawExp = dataRef.get("raw")
132 maskedImage = rawExp.getMaskedImage()
133
134 # Support extra debug output.
135 # -
136 import lsstDebug
137 display = lsstDebug.Info(__name__).display
138 if display:
139 frame = 1
140 disp = afwDisplay.Display(frame=frame)
141 disp.mtv(rawExp, title="exposure")
142
143 # return the pipe_base Struct that is returned by self.stats.run
144 return self.stats.run(maskedImage)
145
146 def _getConfigName(self):
147 """!Get the name prefix for the task config's dataset type, or None to prevent persisting the config
148
149 This override returns None to avoid persisting metadata for this trivial task.
150
151 However, if the method returns a name, then the full name of the dataset type will be <name>_config.
152 The default CmdLineTask._getConfigName returns _DefaultName,
153 which for this task would result in a dataset name of "exampleTask_config".
154
155 Normally you can use the default CmdLineTask._getConfigName, but here are two reasons
156 why you might want to override it:
157 - If you do not want your task to write its config, then have the override return None.
158 That is done for this example task, because I didn't want to clutter up the
159 repository with config information for a trivial task.
160 - If the default name would not be unique. An example is
161 \ref lsst.pipe.tasks.makeSkyMap.MakeSkyMapTask "MakeSkyMapTask": it makes a
162 \ref lsst.skymap.SkyMap "sky map" (sky pixelization for a coadd)
163 for any of several different types of coadd, such as deep or goodSeeing.
164 As such, the name of the persisted config must include the coadd type in order to be unique.
165
166 Normally if you override _getConfigName then you override _getMetadataName to match.
167 """
168 return None
169
170 def _getMetadataName(self):
171 """!Get the name prefix for the task metadata's dataset type, or None to prevent persisting metadata
172
173 This override returns None to avoid persisting metadata for this trivial task.
174
175 However, if the method returns a name, then the full name of the dataset type will be <name>_metadata.
176 The default CmdLineTask._getConfigName returns _DefaultName,
177 which for this task would result in a dataset name of "exampleTask_metadata".
178
179 See the description of _getConfigName for reasons to override this method.
180 """
181 return None
Example command-line task that computes simple statistics on an image.
def runDataRef(self, dataRef)
Compute a few statistics on the image plane of an exposure.
Make a sky map in a repository.
Definition: makeSkyMap.py:83