Inheritance diagram for lsst.meas.base.diaCalculationPlugins.StetsonJDiaPsfFlux:
Public Member Functions | |
| getExecutionOrder (cls) | |
| calculate (self, diaObjects, diaSources, filterDiaSources, band, **kwargs) | |
Static Public Attributes | |
| ConfigClass = LinearFitDiaPsfFluxConfig | |
| list | inputCols = ["psfFluxMean"] |
| list | outputCols = ["psfFluxStetsonJ"] |
| str | plugType = "multi" |
| bool | needsFilter = True |
Protected Member Functions | |
| _stetson_J (self, fluxes, errors, mean=None) | |
| _stetson_mean (self, values, errors, mean=None, alpha=2., beta=2., n_iter=20, tol=1e-6) | |
Detailed Description
Compute the StetsonJ statistic on the DIA point source fluxes.
Definition at line 851 of file diaCalculationPlugins.py.
Member Function Documentation
◆ _stetson_J()
|
protected |
Compute the single band stetsonJ statistic.
Parameters
----------
fluxes : `numpy.ndarray` (N,)
Calibrated lightcurve flux values.
errors : `numpy.ndarray` (N,)
Errors on the calibrated lightcurve fluxes.
mean : `float`
Starting mean from previous plugin.
Returns
-------
stetsonJ : `float`
stetsonJ statistic for the input fluxes and errors.
References
----------
.. [1] Stetson, P. B., "On the Automatic Determination of Light-Curve
Parameters for Cepheid Variables", PASP, 108, 851S, 1996
Definition at line 909 of file diaCalculationPlugins.py.
909 def _stetson_J(self, fluxes, errors, mean=None):
910 """Compute the single band stetsonJ statistic.
911
912 Parameters
913 ----------
914 fluxes : `numpy.ndarray` (N,)
915 Calibrated lightcurve flux values.
916 errors : `numpy.ndarray` (N,)
917 Errors on the calibrated lightcurve fluxes.
918 mean : `float`
919 Starting mean from previous plugin.
920
921 Returns
922 -------
923 stetsonJ : `float`
924 stetsonJ statistic for the input fluxes and errors.
925
926 References
927 ----------
928 .. [1] Stetson, P. B., "On the Automatic Determination of Light-Curve
929 Parameters for Cepheid Variables", PASP, 108, 851S, 1996
930 """
931 n_points = len(fluxes)
932 flux_mean = self._stetson_mean(fluxes, errors, mean)
933 delta_val = (
934 np.sqrt(n_points / (n_points - 1)) * (fluxes - flux_mean) / errors)
935 p_k = delta_val ** 2 - 1
936
937 return np.mean(np.sign(p_k) * np.sqrt(np.fabs(p_k)))
938
◆ _stetson_mean()
|
protected |
Compute the stetson mean of the fluxes which down-weights outliers.
Weighted biased on an error weighted difference scaled by a constant
(1/``a``) and raised to the power beta. Higher betas more harshly
penalize outliers and ``a`` sets the number of sigma where a weighted
difference of 1 occurs.
Parameters
----------
values : `numpy.dnarray`, (N,)
Input values to compute the mean of.
errors : `numpy.ndarray`, (N,)
Errors on the input values.
mean : `float`
Starting mean value or None.
alpha : `float`
Scalar down-weighting of the fractional difference. lower->more
clipping. (Default value is 2.)
beta : `float`
Power law slope of the used to down-weight outliers. higher->more
clipping. (Default value is 2.)
n_iter : `int`
Number of iterations of clipping.
tol : `float`
Fractional and absolute tolerance goal on the change in the mean
before exiting early. (Default value is 1e-6)
Returns
-------
mean : `float`
Weighted stetson mean result.
References
----------
.. [1] Stetson, P. B., "On the Automatic Determination of Light-Curve
Parameters for Cepheid Variables", PASP, 108, 851S, 1996
Definition at line 939 of file diaCalculationPlugins.py.
946 tol=1e-6):
947 """Compute the stetson mean of the fluxes which down-weights outliers.
948
949 Weighted biased on an error weighted difference scaled by a constant
950 (1/``a``) and raised to the power beta. Higher betas more harshly
951 penalize outliers and ``a`` sets the number of sigma where a weighted
952 difference of 1 occurs.
953
954 Parameters
955 ----------
956 values : `numpy.dnarray`, (N,)
957 Input values to compute the mean of.
958 errors : `numpy.ndarray`, (N,)
959 Errors on the input values.
960 mean : `float`
961 Starting mean value or None.
962 alpha : `float`
963 Scalar down-weighting of the fractional difference. lower->more
964 clipping. (Default value is 2.)
965 beta : `float`
966 Power law slope of the used to down-weight outliers. higher->more
967 clipping. (Default value is 2.)
968 n_iter : `int`
969 Number of iterations of clipping.
970 tol : `float`
971 Fractional and absolute tolerance goal on the change in the mean
972 before exiting early. (Default value is 1e-6)
973
974 Returns
975 -------
976 mean : `float`
977 Weighted stetson mean result.
978
979 References
980 ----------
981 .. [1] Stetson, P. B., "On the Automatic Determination of Light-Curve
982 Parameters for Cepheid Variables", PASP, 108, 851S, 1996
983 """
984 n_points = len(values)
985 n_factor = np.sqrt(n_points / (n_points - 1))
986 inv_var = 1 / errors ** 2
987
988 if mean is None:
989 mean = np.average(values, weights=inv_var)
990 for iter_idx in range(n_iter):
991 chi = np.fabs(n_factor * (values - mean) / errors)
992 tmp_mean = np.average(
993 values,
994 weights=inv_var / (1 + (chi / alpha) ** beta))
995 diff = np.fabs(tmp_mean - mean)
996 mean = tmp_mean
997 if diff / mean < tol and diff < tol:
998 break
999 return mean
1000
1001
◆ calculate()
| lsst.meas.base.diaCalculationPlugins.StetsonJDiaPsfFlux.calculate | ( | self, | |
| diaObjects, | |||
| diaSources, | |||
| filterDiaSources, | |||
| band, | |||
| ** | kwargs ) |
Compute the StetsonJ statistic on the DIA point source fluxes.
Parameters
----------
diaObject : `dict`
Summary object to store values in.
diaSources : `pandas.DataFrame`
DataFrame representing all diaSources associated with this
diaObject.
filterDiaSources : `pandas.DataFrame`
DataFrame representing diaSources associated with this
diaObject that are observed in the band pass ``band``.
band : `str`
Simple, string name of the filter for the flux being calculated.
**kwargs
Any additional keyword arguments that may be passed to the plugin.
Reimplemented from lsst.meas.base.diaCalculation.DiaObjectCalculationPlugin.
Definition at line 868 of file diaCalculationPlugins.py.
873 **kwargs):
874 """Compute the StetsonJ statistic on the DIA point source fluxes.
875
876 Parameters
877 ----------
878 diaObject : `dict`
879 Summary object to store values in.
880 diaSources : `pandas.DataFrame`
881 DataFrame representing all diaSources associated with this
882 diaObject.
883 filterDiaSources : `pandas.DataFrame`
884 DataFrame representing diaSources associated with this
885 diaObject that are observed in the band pass ``band``.
886 band : `str`
887 Simple, string name of the filter for the flux being calculated.
888 **kwargs
889 Any additional keyword arguments that may be passed to the plugin.
890 """
891 meanName = "{}_psfFluxMean".format(band)
892
893 def _stetsonJ(df):
894 tmpDf = df[~np.logical_or(np.isnan(df["psfFlux"]),
895 np.isnan(df["psfFluxErr"]))]
896 if len(tmpDf) < 2:
897 return np.nan
898 fluxes = tmpDf["psfFlux"].to_numpy()
899 errors = tmpDf["psfFluxErr"].to_numpy()
900
901 return self._stetson_J(
902 fluxes,
903 errors,
904 diaObjects.at[tmpDf.diaObjectId.iat[0], meanName])
905
906 diaObjects.loc[:, "{}_psfFluxStetsonJ".format(band)] = \
907 filterDiaSources.apply(_stetsonJ)
908
◆ getExecutionOrder()
| lsst.meas.base.diaCalculationPlugins.StetsonJDiaPsfFlux.getExecutionOrder | ( | cls | ) |
Used to set the relative order of plugin execution.
The values returned by `getExecutionOrder` are compared across all
plugins, and smaller numbers run first.
Notes
-----
`CatalogCalculationPlugin`\s must run with
`BasePlugin.DEFAULT_CATALOGCALCULATION` or higher.
All plugins must implement this method with an appropriate run level
Reimplemented from lsst.meas.base.catalogCalculation.CatalogCalculationPlugin.
Definition at line 865 of file diaCalculationPlugins.py.
865 def getExecutionOrder(cls):
866 return cls.FLUX_MOMENTS_CALCULATED
867
Member Data Documentation
◆ ConfigClass
|
static |
Definition at line 855 of file diaCalculationPlugins.py.
◆ inputCols
|
static |
Definition at line 858 of file diaCalculationPlugins.py.
◆ needsFilter
|
static |
Definition at line 862 of file diaCalculationPlugins.py.
◆ outputCols
|
static |
Definition at line 860 of file diaCalculationPlugins.py.
◆ plugType
|
static |
Definition at line 861 of file diaCalculationPlugins.py.
The documentation for this class was generated from the following file:
- /j/snowflake/release/lsstsw/stack/lsst-scipipe-8.0.0/Linux64/meas_base/g48712c4677+f88676dd22/python/lsst/meas/base/diaCalculationPlugins.py
