Python general.insert_extracted_sources函数代码示例

    def test_basic_same_field_case(self):
        """ Here we start with 1 source in image0.
        We then add image1 (same field as image0), with a double association
        for the source, and check assocskyrgn updates correctly.
       """
        n_images = 2
        im_params = db_subs.generate_timespaced_dbimages_data(n_images)

        idx = 0
        src_a = db_subs.example_extractedsource_tuple(
                        ra=im_params[idx]['centre_ra'],
                        dec=im_params[idx]['centre_decl'])

        src_b = src_a._replace(ra=src_a.ra + 1. / 60.) # 1 arcminute offset
        imgs = []
        imgs.append(tkp.db.Image(dataset=self.dataset, data=im_params[idx]))
        insert_extracted_sources(imgs[idx]._id, [src_a])
        associate_extracted_sources(imgs[idx]._id, deRuiter_r, new_source_sigma_margin)

        idx = 1
        imgs.append(tkp.db.Image(dataset=self.dataset, data=im_params[idx]))
        insert_extracted_sources(imgs[idx]._id, [src_a, src_b])
        associate_extracted_sources(imgs[idx]._id, deRuiter_r, new_source_sigma_margin)
        imgs[idx].update()
        runcats = columns_from_table('runningcatalog',
                                where={'dataset':self.dataset.id})
        self.assertEqual(len(runcats), 2) #Just a sanity check.
        skyassocs = columns_from_table('assocskyrgn',
                                   where={'skyrgn':imgs[idx]._data['skyrgn']})
        self.assertEqual(len(skyassocs), 2)

    def test_infinite(self):
        # Check that database insertion doesn't choke on infinite errors.

        dataset = DataSet(data={'description': 'example dataset'},
                           database=self.database)
        image = Image(dataset=dataset, data=db_subs.example_dbimage_data_dict())

        # Inserting a standard example extractedsource should be fine
        extracted_source = db_subs.example_extractedsource_tuple()
        insert_extracted_sources(image._id, [extracted_source])
        inserted = columns_from_table('extractedsource',
                                      where= {'image' : image.id})
        self.assertEqual(len(inserted), 1)

        # But if the source has infinite errors we drop it and log a warning
        extracted_source = db_subs.example_extractedsource_tuple(error_radius=float('inf'),
                                                                 peak_err=float('inf'),
                                                                 flux_err=float('inf'))

                # We will add a handler to the root logger which catches all log
        # output in a buffer.
        iostream = BytesIO()
        hdlr = logging.StreamHandler(iostream)
        logging.getLogger().addHandler(hdlr)

        insert_extracted_sources(image._id, [extracted_source])

        logging.getLogger().removeHandler(hdlr)
        # We want to be sure that the error has been appropriately logged.
        self.assertIn("Dropped source fit with infinite flux errors",
                      iostream.getvalue())

        inserted = columns_from_table('extractedsource',
                                      where= {'image' : image.id})
        self.assertEqual(len(inserted), 1)

    def test_probably_not_a_transient(self):
        """
        No source at 250MHz, but we detect a source at 50MHz.
        Not necessarily a transient.
        Should trivially ignore 250MHz data when looking at a new 50MHz source.
        """
        img_params = self.img_params

        img0 = img_params[0]

        # This time around, we just manually exclude the steady src from
        # the first image detections.
        steady_low_freq_src = MockSource(
            example_extractedsource_tuple(ra=img_params[0]['centre_ra'],
                                          dec=img_params[0]['centre_decl']
                                          ),
            lightcurve=defaultdict(lambda :self.always_detectable_flux)
        )

        # Insert first image, no sources.
        tkp.db.Image(data=img_params[0],dataset=self.dataset)
        # Now set up second image.
        img1 = tkp.db.Image(data=img_params[1],dataset=self.dataset)
        xtr = steady_low_freq_src.simulate_extraction(img1,
                                                    extraction_type='blind')
        insert_extracted_sources(img1._id, [xtr], 'blind')
        associate_extracted_sources(img1._id, deRuiter_r, self.new_source_sigma_margin)
        transients = get_newsources_for_dataset(self.dataset.id)

        # Should have no marked transients
        self.assertEqual(len(transients), 0)

    def insert_extracted_sources(self, results, extract="blind"):
        """Insert a list of sources

        Args:

            results (list): list of
                utility.containers.ExtractionResult objects (as
                returned from
                sourcefinder.image.ImageData().extract()), or a list
                of data tuples with the source information as follows:
                (ra, dec,
                ra_fit_err, dec_fit_err,
                peak, peak_err,
                flux, flux_err,
                significance level,
                beam major width (as), beam minor width(as),
                beam parallactic angle
                ew_sys_err, ns_sys_err,
                error_radius).
            extract (str):'blind', 'ff_nd' or 'ff_ms'
                (see db.general.insert_extracted_sources)
       """
        # To do: Figure out a saner method of passing the results around
        # (Namedtuple, for starters?)

        insert_extracted_sources(self._id, results=results, extract_type=extract)

    def test_two_field_overlap_new_transient(self):
        """Now for something more interesting - two overlapping fields, 4 sources:
        one steady source only in lower field,
        one steady source in both fields,
        one steady source only in upper field,
        one transient source in both fields but only at 2nd timestep.
        """
        n_images = 2
        xtr_radius = 1.5
        im_params = db_subs.generate_timespaced_dbimages_data(n_images,
                                                     xtr_radius=xtr_radius)
        im_params[1]['centre_decl'] += xtr_radius * 1

        imgs = []

        lower_steady_src = db_subs.example_extractedsource_tuple(
                                ra=im_params[0]['centre_ra'],
                                dec=im_params[0]['centre_decl'] - 0.5 * xtr_radius)
        upper_steady_src = db_subs.example_extractedsource_tuple(
                                ra=im_params[1]['centre_ra'],
                                dec=im_params[1]['centre_decl'] + 0.5 * xtr_radius)
        overlap_steady_src = db_subs.example_extractedsource_tuple(
                                ra=im_params[0]['centre_ra'],
                                dec=im_params[0]['centre_decl'] + 0.2 * xtr_radius)
        overlap_transient = db_subs.example_extractedsource_tuple(
                                ra=im_params[0]['centre_ra'],
                                dec=im_params[0]['centre_decl'] + 0.8 * xtr_radius)

        imgs.append(tkp.db.Image(dataset=self.dataset, data=im_params[0]))
        imgs.append(tkp.db.Image(dataset=self.dataset, data=im_params[1]))

        insert_extracted_sources(imgs[0]._id, [lower_steady_src, overlap_steady_src])
        associate_extracted_sources(imgs[0]._id, deRuiter_r=0.1,
                                    new_source_sigma_margin=new_source_sigma_margin)
        nd_posns = dbnd.get_nulldetections(imgs[0].id)
        self.assertEqual(len(nd_posns), 0)

        insert_extracted_sources(imgs[1]._id, [upper_steady_src, overlap_steady_src,
                                               overlap_transient])
        associate_extracted_sources(imgs[1]._id, deRuiter_r=0.1,
                                    new_source_sigma_margin=new_source_sigma_margin)
        nd_posns = dbnd.get_nulldetections(imgs[1].id)
        self.assertEqual(len(nd_posns), 0)

        runcats = columns_from_table('runningcatalog',
                                where={'dataset': self.dataset.id})
        self.assertEqual(len(runcats), 4) #sanity check.

        newsources_qry = """\
        SELECT *
          FROM newsource tr
              ,runningcatalog rc
        WHERE rc.dataset = %s
          AND tr.runcat = rc.id
        """
        self.database.cursor.execute(newsources_qry, (self.dataset.id,))
        newsources = get_db_rows_as_dicts(self.database.cursor)
        self.assertEqual(len(newsources), 1)

    def test_marginal_transient(self):
        """
        ( flux1 > (rms_min0*(det0 + margin) )
        but ( flux1 < (rms_max0*(det0 + margin) )
        --> Possible transient

        If it was in a region of rms_min, we would (almost certainly) have seen
        it in the first image. So new source --> Possible transient.
        But if it was in a region of rms_max, then perhaps we would have missed
        it. In which case, new source --> Just seeing deeper.

        Note that if we are tiling overlapping images, then the first time
        a field is processed with image-centre at the edge of the old field,
        we may get a bunch of unhelpful 'possible transients'.

        Furthermore, this will pick up fluctuating sources near the
        image-margins even with a fixed field of view.
        But without a more complex store of image-rms-per-position, we cannot
        do better.
        Hopefully we can use a 'distance from centre' feature to separate out
        the good and bad candidates in this case.
        """
        img_params = self.img_params

        #Must pick flux value carefully to fire correct logic branch:
        marginal_transient_flux = self.reliably_detected_at_image_centre_flux

        marginal_transient = MockSource(
            example_extractedsource_tuple(ra=img_params[0]['centre_ra'],
                                          dec=img_params[0]['centre_decl']),
            lightcurve={img_params[1]['taustart_ts'] : marginal_transient_flux}
        )

        # First, check that we've set up the test correctly
        rms_min0 = img_params[0]['rms_min']
        rms_max0 = img_params[0]['rms_max']
        det0 = img_params[0]['detection_thresh']
        self.assertTrue(marginal_transient_flux <
            rms_max0 * (det0 + self.new_source_sigma_margin))
        self.assertTrue(marginal_transient_flux >
            rms_min0 * (det0 + self.new_source_sigma_margin))

        for pars in self.img_params:
            img = tkp.db.Image(data=pars, dataset=self.dataset)
            xtr = marginal_transient.simulate_extraction(img,
                                                         extraction_type='blind')
            if xtr is not None:
                insert_extracted_sources(img._id, [xtr], 'blind')
            associate_extracted_sources(img._id, deRuiter_r, self.new_source_sigma_margin)

        newsources = get_newsources_for_dataset(self.dataset.id)

        # Should have one 'possible' transient
        self.assertEqual(len(newsources), 1)
        self.assertTrue(
            newsources[0]['low_thresh_sigma'] > self.new_source_sigma_margin)
        self.assertTrue(
            newsources[0]['high_thresh_sigma'] < self.new_source_sigma_margin)

    def test_single_fixed_source(self):
        """test_single_fixed_source

        - Pretend to extract the same source in each of a series of images.
        - Perform source association
        - Check the image source listing works
        - Check runcat, assocxtrsource.
        """

        fixed_src_runcat_id = None
        for img_idx, im in enumerate(self.im_params):
            self.db_imgs.append( Image(data=im, dataset=self.dataset))
            last_img = self.db_imgs[-1]
            insert_extracted_sources(last_img._id,
                [db_subs.example_extractedsource_tuple()],'blind')
            associate_extracted_sources(last_img._id, deRuiter_r,
                                        new_source_sigma_margin)

            running_cat = columns_from_table(table="runningcatalog",
                                           keywords=['id', 'datapoints'],
                                           where={"dataset":self.dataset.id})
            self.assertEqual(len(running_cat), 1)
            self.assertEqual(running_cat[0]['datapoints'], img_idx+1)

            # Check runcat ID does not change for a steady single source
            if img_idx == 0:
                fixed_src_runcat_id = running_cat[0]['id']
                self.assertIsNotNone(fixed_src_runcat_id, "No runcat id assigned to source")
            self.assertEqual(running_cat[0]['id'], fixed_src_runcat_id,
                             "Multiple runcat ids for same fixed source")


            runcat_flux = columns_from_table(table="runningcatalog_flux",
                               keywords=['f_datapoints'],
                               where={"runcat":fixed_src_runcat_id})
            self.assertEqual(len(runcat_flux),1)
            self.assertEqual(img_idx+1, runcat_flux[0]['f_datapoints'])

            last_img.update()
            last_img.update_sources()
            img_xtrsrc_ids = [src.id for src in last_img.sources]
            self.assertEqual(len(img_xtrsrc_ids), 1)

            #Get the association row for most recent extraction:
            assocxtrsrcs_rows = columns_from_table(table="assocxtrsource",
                                       keywords=['runcat', 'xtrsrc' ],
                                       where={"xtrsrc":img_xtrsrc_ids[0]})
#            print "ImageID:", last_img.id
#            print "Imgs sources:", img_xtrsrc_ids
#            print "Assoc entries:", assocxtrsrcs_rows
#            print "First extracted source id:", ds_source_ids[0]
#            if len(assocxtrsrcs_rows):
#                print "Associated source:", assocxtrsrcs_rows[0]['xtrsrc']
            self.assertEqual(len(assocxtrsrcs_rows),1,
                             msg="No entries in assocxtrsrcs for image number "+str(img_idx))
            self.assertEqual(assocxtrsrcs_rows[0]['runcat'], fixed_src_runcat_id,
                             "Mismatched runcat id in assocxtrsrc table")

    def test_only_first_epoch_source(self):
        """test_only_first_epoch_source

        - Pretend to extract a source only from the first image.
        - Run source association for each image, as we would in TraP.
        - Check the image source listing works
        - Check runcat and assocxtrsource are correct.

        """
        first_epoch = True
        extracted_source_ids = []
        for im in self.im_params:
            self.db_imgs.append(Image( data=im, dataset=self.dataset))
            last_img = self.db_imgs[-1]

            if first_epoch:
                insert_extracted_sources(last_img._id,
                    [db_subs.example_extractedsource_tuple()], 'blind')

            associate_extracted_sources(last_img._id, deRuiter_r,
                                        new_source_sigma_margin)

            # First, check the runcat has been updated correctly
            running_cat = columns_from_table(table="runningcatalog",
                                             keywords=['datapoints'],
                                             where={"dataset": self.dataset.id})
            self.assertEqual(len(running_cat), 1)
            self.assertEqual(running_cat[0]['datapoints'], 1)

            last_img.update()
            last_img.update_sources()
            img_xtrsrc_ids = [src.id for src in last_img.sources]

            if first_epoch:
                self.assertEqual(len(img_xtrsrc_ids),1)
                extracted_source_ids.extend(img_xtrsrc_ids)
                assocxtrsrcs_rows = columns_from_table(table="assocxtrsource",
                                           keywords=['runcat', 'xtrsrc' ],
                                           where={"xtrsrc":img_xtrsrc_ids[0]})
                self.assertEqual(len(assocxtrsrcs_rows),1)
                self.assertEqual(assocxtrsrcs_rows[0]['xtrsrc'], img_xtrsrc_ids[0])
            else:
                self.assertEqual(len(img_xtrsrc_ids),0)

            first_epoch=False


        #Assocxtrsources still ok after multiple images?
        self.assertEqual(len(extracted_source_ids),1)
        assocxtrsrcs_rows = columns_from_table(table="assocxtrsource",
                                           keywords=['runcat', 'xtrsrc' ],
                                           where={"xtrsrc":extracted_source_ids[0]})
        self.assertEqual(len(assocxtrsrcs_rows),1)

        self.assertEqual(assocxtrsrcs_rows[0]['xtrsrc'], extracted_source_ids[0],
                         "Runcat xtrsrc entry must match the only extracted source")

    def test_rejected_initial_image(self):
        """
        An image which is rejected should not be taken into account when
        deciding whether a patch of sky has been previously observed, and
        hence whether any detections in that area are (potential) transients.

        Here, we create a database with two images. The first
        (choronologically) is rejected; the second contains a source. That
        source should not be marked as a transient.
        """

        dataset = tkp.db.DataSet(data={"description": "Trans:" + self._testMethodName}, database=tkp.db.Database())

        # We use a dataset with two images
        # NB the routine in db_subs automatically increments time between
        # images.
        n_images = 2
        db_imgs = [
            tkp.db.Image(data=im_params, dataset=dataset)
            for im_params in db_subs.generate_timespaced_dbimages_data(n_images)
        ]

        # The first image is rejected for an arbitrary reason
        # (for the sake of argument, we use an unacceptable RMS).
        db_quality.reject(
            imageid=db_imgs[0].id,
            reason=db_quality.reject_reasons["rms"],
            comment=self._testMethodName,
            session=self.session,
        )
        # Have to commit here: old DB code makes queries in a separate transaction.
        self.session.commit()

        # Since we rejected the first image, we only find a source in the
        # second.
        source = db_subs.example_extractedsource_tuple()
        insert_extracted_sources(db_imgs[1]._id, [source])

        # Standard source association procedure etc.
        associate_extracted_sources(db_imgs[1].id, deRuiter_r=3.7, new_source_sigma_margin=3)

        # Our source should _not_ be a transient. That is, there should be no
        # entries in the newsource table for this dataset.
        cursor = tkp.db.execute(
            """\
            SELECT t.id FROM newsource t, runningcatalog rc
                    WHERE t.runcat = rc.id
                      AND rc.dataset = %(ds_id)s
            """,
            {"ds_id": dataset.id},
        )
        self.assertEqual(cursor.rowcount, 0)

    def test_two_field_overlap_nulling_src(self):
        """Similar to above, but one source disappears:
        Two overlapping fields, 4 sources:
        one steady source only in lower field,
        one steady source in both fields,
        one steady source only in upper field,
        one transient source in both fields but only at *1st* timestep.
        """
        n_images = 2
        xtr_radius = 1.5
        im_params = db_subs.generate_timespaced_dbimages_data(n_images,
                                                     xtr_radius=xtr_radius)
        im_params[1]['centre_decl'] += xtr_radius * 1

        imgs = []

        lower_steady_src = db_subs.example_extractedsource_tuple(
                                ra=im_params[0]['centre_ra'],
                                dec=im_params[0]['centre_decl'] - 0.5 * xtr_radius)
        upper_steady_src = db_subs.example_extractedsource_tuple(
                                ra=im_params[1]['centre_ra'],
                                dec=im_params[1]['centre_decl'] + 0.5 * xtr_radius)
        overlap_steady_src = db_subs.example_extractedsource_tuple(
                                ra=im_params[0]['centre_ra'],
                                dec=im_params[0]['centre_decl'] + 0.2 * xtr_radius)
        overlap_transient = db_subs.example_extractedsource_tuple(
                                ra=im_params[0]['centre_ra'],
                                dec=im_params[0]['centre_decl'] + 0.8 * xtr_radius)

        imgs.append(tkp.db.Image(dataset=self.dataset, data=im_params[0]))
        imgs.append(tkp.db.Image(dataset=self.dataset, data=im_params[1]))

        insert_extracted_sources(imgs[0]._id, [lower_steady_src, overlap_steady_src,
                                               overlap_transient])
        associate_extracted_sources(imgs[0]._id, deRuiter_r=0.1,
                                    new_source_sigma_margin=new_source_sigma_margin)
        nd_posns = dbnd.get_nulldetections(imgs[0].id)
        self.assertEqual(len(nd_posns), 0)

        insert_extracted_sources(imgs[1]._id, [upper_steady_src, overlap_steady_src])
        associate_extracted_sources(imgs[1]._id, deRuiter_r=0.1,
                                            new_source_sigma_margin=new_source_sigma_margin)
        #This time we don't expect to get an immediate transient detection,
        #but we *do* expect to get a null-source forced extraction request:
        nd_posns = dbnd.get_nulldetections(imgs[1].id)
        self.assertEqual(len(nd_posns), 1)

        runcats = columns_from_table('runningcatalog',
                                where={'dataset':self.dataset.id})
        self.assertEqual(len(runcats), 4) #sanity check.

def insert_image_and_simulated_sources(dataset, image_params, mock_sources,
                                       new_source_sigma_margin,
                                       deruiter_radius=3.7):
    """
    Simulates the standard database image-and-source insertion logic using mock
    sources.

    Args:
        dataset: The dataset object
        image_params (dict): Contains the image properties.
        mock_sources (list of MockSource): The mock sources to simulate.
        new_source_sigma_margin (float): Parameter passed to source-association
            routines.
        deruiter_radius (float): Parameter passed to source-association
            routines.

    Returns:
        3-tuple (image, list of blind extractions, list of forced fits).

    """
    image = tkp.db.Image(data=image_params,dataset=dataset)
    blind_extractions=[]
    for src in mock_sources:
        xtr = src.simulate_extraction(image,extraction_type='blind')
        if xtr is not None:
            blind_extractions.append(xtr)
    image.insert_extracted_sources(blind_extractions,'blind')
    image.associate_extracted_sources(deRuiter_r=deruiter_radius,
        new_source_sigma_margin=new_source_sigma_margin)
    nd_ids_posns = nulldetections.get_nulldetections(image.id)
    nd_posns = [(ra,decl) for ids, ra, decl in nd_ids_posns]
    forced_fits = []
    for posn in nd_posns:
        for src in mock_sources:
            eps = 1e-13
            if (math.fabs(posn[0] - src.base_source.ra)<eps and
                        math.fabs(posn[1] - src.base_source.dec)<eps ):
                forced_fits.append(
                    src.simulate_extraction(image,extraction_type='ff_nd')
                )
    if len(nd_posns) != len(forced_fits):
        raise LookupError("Something went wrong, nulldetection position did "
                          "not match a mock source.")
    #image.insert_extracted_sources(forced_fits, 'ff_nd')
    dbgen.insert_extracted_sources(image.id, forced_fits, 'ff_nd',
                   ff_runcat_ids=[ids for ids, ra, decl in nd_ids_posns])
    nulldetections.associate_nd(image.id)

    return image, blind_extractions, forced_fits

    def test_new_skyregion_insertion(self):
        """Here we test the association logic executed upon insertion of a
        new skyregion.

        We expect that any pre-existing entries in the runningcatalog
        which lie within the field of view will be marked as
        'within this region', through the presence of an entry in table
        ``assocskyrgn``.
        Conversely sources outside the FoV should not be marked as related.

        We begin with img0, with a source at centre.
        Then we add 2 more (empty) images/fields at varying positions.
        """
        n_images = 6
        im_params = db_subs.generate_timespaced_dbimages_data(n_images)

        src_in_img0 = db_subs.example_extractedsource_tuple(
                        ra=im_params[0]['centre_ra'],
                        dec=im_params[0]['centre_decl'],)

        # First image
        image0 = tkp.db.Image(dataset=self.dataset, data=im_params[0])
        insert_extracted_sources(image0._id, [src_in_img0])
        associate_extracted_sources(image0._id, deRuiter_r, new_source_sigma_margin)
        image0.update()

        runcats = columns_from_table('runningcatalog',
                                where={'dataset':self.dataset.id})
        self.assertEqual(len(runcats), 1) #Just a sanity check.
        ##Second, different *But overlapping* image:
        idx = 1
        im_params[idx]['centre_decl'] += im_params[idx]['xtr_radius'] * 0.9
        image1 = tkp.db.Image(dataset=self.dataset, data=im_params[idx])
        image1.update()

        assocs = columns_from_table('assocskyrgn',
                                    where={'skyrgn':image1._data['skyrgn']})
        self.assertEqual(len(assocs), 1)
        self.assertEqual(assocs[0]['runcat'], runcats[0]['id'])

        ##Third, different *and NOT overlapping* image:
        idx = 2
        im_params[idx]['centre_decl'] += im_params[idx]['xtr_radius'] * 1.1
        image2 = tkp.db.Image(dataset=self.dataset, data=im_params[idx])
        image2.update()
        assocs = columns_from_table('assocskyrgn',
                                    where={'skyrgn':image2._data['skyrgn']})
        self.assertEqual(len(assocs), 0)

    def test_null_case_sequential(self):
        """test_null_case_sequential

        -Check extractedsource insertion routines can deal with empty input!
        -Check source association can too

        """
        for im in self.im_params:
            self.db_imgs.append(Image(data=im, dataset=self.dataset))
            insert_extracted_sources(self.db_imgs[-1]._id, [],'blind')
            associate_extracted_sources(self.db_imgs[-1]._id, deRuiter_r,
                                        new_source_sigma_margin)
            running_cat = columns_from_table(table="runningcatalog",
                                             keywords="*",
                                             where={"dataset":self.dataset.id})
            self.assertEqual(len(running_cat), 0)

    def test_one2oneflux(self):
        dataset = tkp.db.DataSet(database=self.database, data={'description': 'flux test set: 1-1'})
        n_images = 3
        im_params = db_subs.generate_timespaced_dbimages_data(n_images)

        src_list = []
        src = db_subs.example_extractedsource_tuple()
        src0 = src._replace(flux=2.0)
        src_list.append(src0)
        src1 = src._replace(flux=2.5)
        src_list.append(src1)
        src2 = src._replace(flux=2.4)
        src_list.append(src2)

        for idx, im in enumerate(im_params):
            image = tkp.db.Image(database=self.database, dataset=dataset, data=im)
            insert_extracted_sources(image._id, [src_list[idx]])
            associate_extracted_sources(image.id, deRuiter_r=3.717)

        query = """\
        SELECT rf.avg_f_int
          FROM runningcatalog r
              ,runningcatalog_flux rf
         WHERE r.dataset = %(dataset)s
           AND r.id = rf.runcat
        """
        self.database.cursor.execute(query, {'dataset': dataset.id})
        result = zip(*self.database.cursor.fetchall())
        avg_f_int = result[0]
        self.assertEqual(len(avg_f_int), 1)
        py_metrics = db_subs.lightcurve_metrics(src_list)
        self.assertAlmostEqual(avg_f_int[0], py_metrics[-1]['avg_f_int'])
        runcat_id = columns_from_table('runningcatalog',
                                       where={'dataset':dataset.id})
        self.assertEqual(len(runcat_id),1)
        runcat_id = runcat_id[0]['id']
        # Check evolution of variability indices
        db_metrics = db_queries.get_assoc_entries(self.database,
                                                           runcat_id)
        self.assertEqual(len(db_metrics), n_images)
        # Compare the python- and db-calculated values
        for i in range(len(db_metrics)):
            for key in ('v_int','eta_int'):
                self.assertAlmostEqual(db_metrics[i][key], py_metrics[i][key])

    def test_two_field_basic_case(self):
        """
        Here we create 2 disjoint image fields, with one source at centre of
        each, and check that the second source inserted does not get flagged as
        newsource.
        """
        n_images = 2
        xtr_radius = 1.5
        im_params = db_subs.generate_timespaced_dbimages_data(n_images,
                                                     xtr_radius=xtr_radius)
        im_params[1]['centre_decl'] += xtr_radius * 2 + 0.5

        imgs = []
        for idx in range(len(im_params)):
            imgs.append(tkp.db.Image(dataset=self.dataset, data=im_params[idx]))

        for idx in range(len(im_params)):
            central_src = db_subs.example_extractedsource_tuple(
                                    ra=im_params[idx]['centre_ra'],
                                    dec=im_params[idx]['centre_decl'])

            imgs.append(tkp.db.Image(dataset=self.dataset, data=im_params[idx]))
            insert_extracted_sources(imgs[idx]._id, [central_src])
            associate_extracted_sources(imgs[idx]._id, deRuiter_r, new_source_sigma_margin)

        runcats = columns_from_table('runningcatalog',
                                where={'dataset':self.dataset.id})

        self.assertEqual(len(runcats), 2) #Just a sanity check.

        newsources_qry = """\
        SELECT *
          FROM newsource tr
              ,runningcatalog rc
        WHERE rc.dataset = %s
          AND tr.runcat = rc.id
        """
        self.database.cursor.execute(newsources_qry, (self.dataset.id,))
        newsources = get_db_rows_as_dicts(self.database.cursor)
        self.assertEqual(len(newsources), 0)