Catalog¶

class mpdaf.sdetect.Catalog(*args, **kwargs)[source]¶

Bases: astropy.table.Table

This class inherits from astropy.table.Table. Its goal is to manage a list of objects.

Initialize a Catalog instance

Parameters:	idname : `str`, optional Table column name containing object IDs raname : `str`, optional Table column name containing object RA coords decname : `str`, optional Table column name containing object DEC coords Remaining args and kwargs are passed to `astropy.table.Table.__init__`.

Methods Summary

`edgedist`(self, wcs[, ra, dec])	Return the smallest distance of all catalog sources center to the edge of the WCS of the given image.
`from_path`(path[, fmt, pattern])	Construct a catalog from a list of source objects which are contains in the directory given as input.
`from_sources`(sources[, fmt])	Construct a catalog from a list of source objects.
`hstack`(self, cat2, \\kwargs)	Peforms an `astropy.table.hstack` with another catalog, but also handles the metadata correctly.
`join`(self, cat2, \\kwargs)	Peforms an `astropy.table.join` with another catalog, but also handles the metadata correctly.
`masked_invalid`(self)	Mask where invalid values occur (NaNs or infs or -9999 or ‘’).
`match`(self, cat2[, radius, colc1, colc2, …])	Match elements of the current catalog with an other (in RA, DEC).
`match3Dline`(self, cat2, linecolc1, linecolc2)	3D Match elements of the current catalog with an other using spatial (RA, DEC) and list of spectral lines location.
`nearest`(self, coord[, colcoord, ksel, maxdist])	Return the nearest sources with respect to the given coordinate.
`plot_symb`(self, ax, wcs[, label, esize, …])	This function plots the sources location from the catalog.
`select`(self, wcs[, ra, dec, margin, mask])	Select all sources from catalog which are inside the given WCS and return a new catalog.
`to_ds9_regions`(self, outfile[, ra, dec, …])	Return an `astropy.coordinates.SkyCoord` object.
`to_skycoord`(self[, ra, dec, frame, unit])	Return an `astropy.coordinates.SkyCoord` object.
`write`(self, \args, \\*kwargs)	Write this Table object out in the specified format.

Methods Documentation

edgedist(self, wcs, ra=None, dec=None)[source]¶

Return the smallest distance of all catalog sources center to the edge of the WCS of the given image.

Parameters:	wcs : `WCS` Image WCS ra : `str` Name of the column that contains RA values in degrees dec : `str` Name of the column that contains DEC values in degrees
Returns:	`numpy.ndarray` The distance in arcsec units.

classmethod from_path(path, fmt='default', pattern='*.fits')[source]¶

Construct a catalog from a list of source objects which are contains in the directory given as input.

The new catalog will contain all data stored in the primary headers and in the tables extensions of the sources:

a column per header fits (‘SIMPLE’, ‘BITPIX’, ‘NAXIS’, ‘EXTEND’, ‘DATE’, ‘AUTHOR’, ‘COM*’ and ‘HIST*’ are excluded)
two columns per magnitude band: [BAND] [BAND]_ERR
three columns per redshift Z_[Z_DESC], Z_[Z_DESC]_MIN and Z_[Z_DESC]_MAX
several columns per line.

The lines columns depend of the format. By default the columns names are created around unique LINE name [LINE]_[LINES columns names]. But it is possible to use a working format. [LINES columns names]_xxx where xxx is the number of lines present in each source.

Parameters:	path : `str` Directory containing Source files fmt : `str` ‘working’\|’default’ Format of the catalog. The format differs for the LINES table. pattern : `str` Pattern used to select the files, default to `*.fits`.

classmethod from_sources(sources, fmt='default')[source]¶

Construct a catalog from a list of source objects.

The new catalog will contain all data stored in the primary headers and in the tables extensions of the sources:

a column per header fits (‘SIMPLE’, ‘BITPIX’, ‘NAXIS’, ‘EXTEND’, ‘DATE’, ‘AUTHOR’, ‘COM*’ and ‘HIST*’ are excluded)
two columns per magnitude band: [BAND] [BAND]_ERR
three columns per redshift Z_[Z_DESC], Z_[Z_DESC]_MIN and Z_[Z_DESC]_MAX
several columns per line.

The lines columns depend of the format. By default the columns names are created around unique LINE name [LINE]_[LINES columns names]. But it is possible to use a working format. [LINES columns names]_xxx where xxx is the number of lines present in each source.

Parameters:	sources : list< `mpdaf.sdetect.Source` > List of `mpdaf.sdetect.Source` objects fmt : `str` ‘working’\|’default’ Format of the catalog. The format differs for the LINES table.

hstack(self, cat2, **kwargs)[source]¶

Peforms an astropy.table.hstack with another catalog, but also handles the metadata correctly.

Parameters:	cat2 : `astropy.table.Table` Catalog to stack with. Remaining args and kwargs are passed to `astropy.table.hstack`, excecpt metadata_conflicts.
Returns:	stacked : `Catalog` `object` New catalog containing the stacked data

join(self, cat2, **kwargs)[source]¶

Peforms an astropy.table.join with another catalog, but also handles the metadata correctly.

Parameters:	cat2 : `astropy.table.Table` Right catalog to join with. Remaining args and kwargs are passed to `astropy.table.join`, excecpt metadata_conflicts.
Returns:	joined : `Table` `object` New table containing the result of the join operation.

masked_invalid(self)[source]¶: Mask where invalid values occur (NaNs or infs or -9999 or ‘’).

match(self, cat2, radius=1, colc1=(None, None), colc2=(None, None), full_output=True, **kwargs)[source]¶

Match elements of the current catalog with an other (in RA, DEC).

Parameters:	cat2 : `astropy.table.Table` Catalog to match. radius : `float` Matching size in arcsec (default 1). colc1: tuple Name of ra,dec columns in input table. colc2: tuple Name of ra,dec columns in cat2. full_output: bool output flag **kwargs Other arguments are passed to `astropy.coordinates.match_coordinates_sky`.
Returns:	out : `astropy.Table`, `astropy.Table`, `astropy.Table` If `full_output` is True, return a tuple `(match, nomatch1, nomatch2)` where: match: table of matched elements in RA,DEC. nomatch1: sub-table of non matched elements of the current catalog. nomatch2: sub-table of non matched elements of the catalog cat2. If `full_output` is False, only `match` is returned.

match3Dline(self, cat2, linecolc1, linecolc2, spatial_radius=1, spectral_window=5, suffix=('_1', '_2'), full_output=True, colc1=(None, None), colc2=(None, None), **kwargs)[source]¶

3D Match elements of the current catalog with an other using spatial (RA, DEC) and list of spectral lines location.

Parameters:

cat2 : astropy.table.Table: Catalog to match.
linecolc1: list of float: List of column names containing the wavelengths of the input catalog.
linecolc2: list of float: List of column names containing the wavelengths of the cat2.
spatial_radius : float: Matching radius size in arcsec (default 1).
spectral_window : float (default 5): Matching wavelength window in spectral unit (default 5).
colc1: tuple: (‘RA’,’DEC’) name of ra,dec columns of input catalog.
colc2: tuple: (‘RA’,’DEC’) name of ra,dec columns of cat2.
full_output: bool: output flag
**kwargs: Other arguments are passed to astropy.coordinates.match_coordinates_sky.

Returns:

out : astropy.Table, astropy.Table, astropy.Table

If full_output is True, return a tuple (match3d, match2d, nomatch1, nomatch2) where:

match3d, match2d: table of matched elements in RA,DEC.
nomatch1: sub-table of non matched elements of the current catalog.
nomatch2: sub-table of non matched elements of the catalog cat2.

If full_output is False, only match is returned.

nearest(self, coord, colcoord=(None, None), ksel=1, maxdist=None, **kwargs)[source]¶

Return the nearest sources with respect to the given coordinate.

Parameters:

coord: tuple: ra,dec in decimal degree, or HH:MM:SS,DD:MM:SS
colcoord: tuple of str: column names of coordinate: default (‘RA’,’DEC’)
ksel: int: Number of sources to return, default 1 (if None return all sources sorted by distance)
maxdist: float: Maximum distance to source in arcsec, default None
**kwargs: Other arguments are passed to astropy.coordinates.match_coordinates_sky.

Returns:

astropy.table.Table: The corresponding catalog of matched sources with the additional Distance column (arcsec).

plot_symb(self, ax, wcs, label=False, esize=0.8, lsize=None, etype='o', ltype=None, ra=None, dec=None, id=None, ecol='k', lcol=None, alpha=1.0, fill=False, fontsize=8, expand=1.7, ledgecol=None, lfacecol=None, npolygon=3, **kwargs)[source]¶

This function plots the sources location from the catalog.

Parameters:

ax : matplotlib.axes.Axes: Matplotlib axis instance (eg ax = fig.add_subplot(2,3,1)).
wcs : mpdaf.obj.WCS: Image WCS.
label: bool: If True catalog ID are displayed.
esize : float: symbol size in arcsec (used only if lsize is not set).
lsize : str: Column name containing the size in arcsec.
etype : str: Type of symbol: o (circle, size=diameter), s (square, size=length), p (polygon, size=diameter) used only if ltype is not set.
ltype : str: Name of column that contain the symbol to use.
ra : str: Name of the column that contains RA values (in degrees).
dec : str: Name of the column that contains DEC values (in degrees).
id : str: Name of the column that contains ID.
lcol: str: Name of the column that contains Color.
ecol : str: Symbol color (only used if lcol is not set).
alpha : float: Symbol transparency.
fill: bool: If True filled symbol are used.
expand: float: Expand factor to write label.
ledgecol: str: Name of the column that contains the edge color.
lfacecol: str: Name of the column that contains the fqce color.
**kwargs: kwargs can be used to set additional plotting properties.

select(self, wcs, ra=None, dec=None, margin=0, mask=None)[source]¶

Select all sources from catalog which are inside the given WCS and return a new catalog.

Parameters:	wcs : `WCS` Image WCS ra : `str` Name of the column that contains RA values in degrees. dec : `str` Name of the column that contains DEC values in degrees. margin : `int` Margin from the edges (pixels). mask : array_like Mask used to filter sources (1 to mask).
Returns:	`mpdaf.sdetect.Catalog` The catalog with selected rows.

to_ds9_regions(self, outfile, ra=None, dec=None, radius=1, frame='fk5', unit_pos='deg', unit_radius='arcsec')[source]¶: Return an astropy.coordinates.SkyCoord object.

to_skycoord(self, ra=None, dec=None, frame='fk5', unit='deg')[source]¶: Return an astropy.coordinates.SkyCoord object.

write(self, *args, **kwargs)[source]¶

Write this Table object out in the specified format.

This function provides the Table interface to the astropy unified I/O layer. This allows easily writing a file in many supported data formats using syntax such as:

>>> from astropy.table import Table
>>> dat = Table([[1, 2], [3, 4]], names=('a', 'b'))
>>> dat.write('table.dat', format='ascii')  

The arguments and keywords (other than format) provided to this function are passed through to the underlying data reader (e.g. write).