Use primary source flag in source count metrics.

python/lsst/ip/diffim/metrics.py

@@ -62,8 +62,9 @@ class NumberSciSourcesMetricTask(MetricTask):
 
     Notes
     -----
-    The task excludes any sky sources in the catalog, but it does not require
-    that the catalog include a ``sky_sources`` column.
+    The task excludes any non-primary sources in the catalog, but it does
+    not require that the catalog include a ``detect_isPrimary`` or
+    ``sky_sources`` column.
     """
     _DefaultName = "numSciSources"
     ConfigClass = NumberSciSourcesMetricConfig
@@ -128,8 +129,9 @@ class FractionDiaSourcesToSciSourcesMetricTask(MetricTask):
 
     Notes
     -----
-    The task excludes any sky sources in the direct source catalog, but it
-    does not require that either catalog include a ``sky_sources`` column.
+    The task excludes any non-primary sources in the catalog, but it does
+    not require that the catalog include a ``detect_isPrimary`` or
+    ``sky_sources`` column.
     """
     _DefaultName = "fracDiaSourcesToSciSources"
     ConfigClass = FractionDiaSourcesToSciSourcesMetricConfig
@@ -171,8 +173,10 @@ def run(self, sciSources, diaSources):
 def _countRealSources(catalog):
     """Return the number of valid sources in a catalog.
 
-    At present, this definition excludes sky sources. If a catalog does not
-    have a ``sky_source`` flag, all sources are assumed to be non-sky.
+    At present, this definition includes only primary sources. If a catalog
+    does not have a ``detect_isPrimary`` flag, this function counts non-sky
+    sources. If it does not have a ``sky_source`` flag, either, all sources
+    are counted.
 
     Parameters
     ----------
@@ -184,7 +188,11 @@ def _countRealSources(catalog):
     count : `int`
         The number of sources that satisfy the criteria.
     """
-    if "sky_source" in catalog.schema:
+    # E712 is not applicable, because afw.table.SourceRecord.ColumnView
+    # is not a bool.
+    if "detect_isPrimary" in catalog.schema:
+        return np.count_nonzero(catalog["detect_isPrimary"] == True)  # noqa: E712
+    elif "sky_source" in catalog.schema:
         return np.count_nonzero(catalog["sky_source"] == False)  # noqa: E712
     else:
         return len(catalog)

tests/test_metrics.py

@@ -36,7 +36,7 @@
     FractionDiaSourcesToSciSourcesMetricTask
 
 
-def _makeDummyCatalog(size, skyFlag=False):
+def _makeDummyCatalog(size, skyFlag=False, priFlag=False):
     """Create a trivial catalog for testing source counts.
 
     Parameters
@@ -47,6 +47,8 @@ def _makeDummyCatalog(size, skyFlag=False):
         If set, the schema is guaranteed to have the ``sky_source`` flag, and
         one row has it set to `True`. If not set, the ``sky_source`` flag is
         not present.
+    priFlag : `bool`
+        As ``skyFlag``, but for a ``detect_isPrimary`` flag.
 
     Returns
     -------
@@ -55,10 +57,14 @@ def _makeDummyCatalog(size, skyFlag=False):
     """
     schema = SourceCatalog.Table.makeMinimalSchema()
     if skyFlag:
-        schema.addField("sky_source", type="Flag", doc="Sky objects.")
+        schema.addField("sky_source", type="Flag", doc="Sky source.")
+    if priFlag:
+        schema.addField("detect_isPrimary", type="Flag", doc="Primary source.")
     catalog = SourceCatalog(schema)
     for i in range(size):
         record = catalog.addNew()
+    if priFlag and size > 0:
+        record["detect_isPrimary"] = True
     if skyFlag and size > 0:
         record["sky_source"] = True
     return catalog
@@ -97,6 +103,15 @@ def testSkySources(self):
         self.assertEqual(meas.metric_name, Name(metric="ip_diffim.numSciSources"))
         assert_quantity_allclose(meas.quantity, (len(catalog) - 1) * u.count)
 
+    def testPrimarySources(self):
+        catalog = _makeDummyCatalog(3, priFlag=True)
+        result = self.task.run(catalog)
+        lsst.pipe.base.testUtils.assertValidOutput(self.task, result)
+        meas = result.measurement
+
+        self.assertEqual(meas.metric_name, Name(metric="ip_diffim.numSciSources"))
+        assert_quantity_allclose(meas.quantity, 1 * u.count)
+
     def testMissingData(self):
         result = self.task.run(None)
         lsst.pipe.base.testUtils.assertValidOutput(self.task, result)
@@ -165,6 +180,16 @@ def testSkySources(self):
         assert_quantity_allclose(meas.quantity,
                                  len(diaCatalog) / (len(sciCatalog) - 1) * u.dimensionless_unscaled)
 
+    def testPrimarySources(self):
+        sciCatalog = _makeDummyCatalog(5, skyFlag=True, priFlag=True)
+        diaCatalog = _makeDummyCatalog(3)
+        result = self.task.run(sciCatalog, diaCatalog)
+        lsst.pipe.base.testUtils.assertValidOutput(self.task, result)
+        meas = result.measurement
+
+        self.assertEqual(meas.metric_name, Name(metric="ip_diffim.fracDiaSourcesToSciSources"))
+        assert_quantity_allclose(meas.quantity, len(diaCatalog) * u.dimensionless_unscaled)
+
 
 # Hack around unittest's hacky test setup system
 del MetricTaskTestCase