Table API

This page documents the public mega-table classes.

RadialMegaTable

Bases: GeneralRegionTable

Mega-table built from radial bins for a (inclined) galaxy disk.

Each ring (annular region) corresponds to a row in the table. Once a table is constructed, additional columns can be added by calculating statistics of images within each ring.

Parameters:

Name	Type	Description	Default
gal_ra_deg	float	Right Ascension of the galaxy center (in degrees).	required
gal_dec_deg	float	Declination of the galaxy center (in degrees).	required
rgal_bin_arcsec	float	Radial width of each ring (in arcseconds).	required
gal_incl_deg	float	Inclination angle of the galaxy (in degrees). Default is 0 degree.	0
gal_posang_deg	float	Position angle of the galaxy (in degrees; North through East). Default is 0 degree.	0
rgal_max_arcsec	float	The maximum galactic radius (in arcseconds) that the outermost ring will cover. Default is to cover out to 20 times the ring width.	None

Methods:

__init__

__init__(gal_ra_deg, gal_dec_deg, rgal_bin_arcsec, gal_incl_deg=0, gal_posang_deg=0, rgal_max_arcsec=None)

read classmethod

read(filename, **kwargs)

Read (and reconstruct) a RadialMegaTable object from file.

Parameters:

Name	Type	Description	Default
filename	str	Name of the file to read.	required
**kwargs	Any	Keyword arguments to be passed to ~astropy.table.read	{}

Returns:

Type	Description
RadialMegaTable	Reconstructed table instance.

format

format(colnames=None, units=None, formats=None, descriptions=None, ignore_missing=False)

Format table content.

Parameters:

Name	Type	Description	Default
colnames	sequence of str	Names of the columns to keep. Columns in the new table will be ordered according to this parameter.	None
units	sequence	Units to which each kept column should be converted. Items can be either ~astropy.units.Unit objects or their string representations.	None
formats	sequence of str	Format specifiers for each kept column.	None
descriptions	sequence of str	Descriptions of each kept column.	None
ignore_missing	bool	Whether to ignore the error when any key in colnames is missing from the original table (default: False). If True, a column will be added with all NaNs.	False

write

write(filename, keep_metadata=True, add_timestamp=True, **kwargs)

Write table to file.

Parameters:

Name	Type	Description	Default
filename	str	Name of the file to write to.	required
keep_metadata	bool	Whether to keep existing metadata (Default: True)	True
add_timestamp	bool	Whether to add a time stamp in the metadata (Default: True)	True
**kwargs	Any	Additional keyword arguments passed to ~astropy.table.Table.write.	{}

find_coords_in_regions

find_coords_in_regions(ra, dec)

Evaluate region membership for each input coordinate.

Parameters:

Name	Type	Description	Default
ra	array_like	R.A. of the coordinates in question	required
dec	array_like	Declination of the coordinates in question	required

Returns:

Type	Description
ndarray	A boolean array indicating whether each region contains each input coordinate. The shape of this array is: (n_coordinate, n_region).

calc_catalog_stats

calc_catalog_stats(entry, ra, dec, stat_func=None, weight=None, colname='new_col', unit='', **kwargs)

Calculate statistics of a catalog entry within each region.

"Catalog" in this context means a table recording both the (ra, dec) coordinates and other properties of a list of identified objects on the sky. Typical examples: molecular cloud catalogs, HII region catalogs, stellar cluster catalogs.

An example catalog entry: the "molecular cloud size" column in a cloud catalog.

Parameters:

Name	Type	Description	Default
entry	array_like	The catalog entry in question.	required
ra	array_like	RA coordinates of the listed objects.	required
dec	array_like	Dec coordinates of the listed objects.	required
stat_func	callable	A function that accepts an array of values and returns a scalar value (which is the calculated statistics). If 'weight' is not None, this function should also accept a keyword named 'weights', which specifies the statistical weight of each value in the array.	None
weight	array_like	If not None, this keyword should be an ndarray specifying the statistical weight of each row in the catalog. Note that in this case, the broadcasted weight array will be passed to 'stat_func' in a keyword named 'weights'.	None
colname	str	Name of a column in the table to save the output values. Default: 'new_col'	'new_col'
unit	str or `~astropy.units.UnitBase`	Physical unit of the output values (default='').	''
**kwargs	Any	Additional keyword arguments passed to stat_func.	{}

calc_image_stats

calc_image_stats(image, ihdu=0, header=None, stat_func=None, weight=None, colname='new_col', unit='', suppress_error=False, **kwargs)

Calculate statistics of an image within each region.

Parameters:

Name	Type	Description	Default
image	str, bytes, path-like, `~astropy.io.fits.HDUList`,	FITS HDU, or ndarray The image to calculate statistics for.	required
ihdu	int	If 'image' is a str or an HDUList, this keyword should specify which HDU (extension) to use (default=0)	0
header	`~astropy.io.fits.Header`	If 'image' is an ndarray, this keyword should be a FITS header providing the WCS information.	None
stat_func	callable	A function that accepts an array of values, and return a scalar value (which is the calculated statistics). If 'weight' is not None, this function should also accept a keyword named 'weights', which specifies the statistical weight of each value in the array.	None
weight	array_like	If not None, this keyword should be an ndarray specifying the statistical weight of each pixel in the input image. Note that in this case, the broadcasted weight array will be passed to 'stat_func' in a keyword named 'weights'.	None
colname	str	Name of a column in the table to save the output values. Default: 'new_col'	'new_col'
unit	str or `~astropy.units.UnitBase`	Physical unit of the output values (default=''). If unit='header', the 'BUNIT' entry in the header is used.	''
suppress_error	bool	Whether to suppress the error message if 'image' looks like a file but is not found on disk (default=False)	False
**kwargs	Any	Additional keyword arguments passed to stat_func.	{}

create_maps_from_columns

create_maps_from_columns(colnames, header, allow_region_overlap=False)

Create 2D maps from data in columns based on a FITS header.

Parameters:

Name	Type	Description	Default
colnames	sequence of str	Name of the columns to create 2D maps for.	required
header	`~astropy.fits.Header`	FITS header defining the WCS of the output 2D maps.	required
allow_region_overlap	bool	If False (default), an error will be raised when regions overlap (i.e., if any pixel belongs in multiple regions). If True, overlapping regions will be allowed, in which case later rows (regions) will overwrite earlier rows.	False

Returns:

Type	Description
list	List of two-dimensional arrays or quantity arrays built from the requested columns.

StripeMegaTable

Bases: GeneralRegionTable

Mega-table built from stripes along a galaxy's minor axis.

Each stripe corresponds to a row in the table. Once a table is constructed, additional columns can be added by calculating statistics of images within each stripe.

Parameters:

Name	Type	Description	Default
gal_ra_deg	float	Right Ascension of the galaxy center (in degrees).	required
gal_dec_deg	float	Declination of the galaxy center (in degrees).	required
gal_posang_deg	float	Position angle of the galaxy (in degrees; North through East). Default is 0 degree.	required
xbin_arcsec	float	Width of each stripe (in arcseconds) along the galaxy major axis.	required
xmax_arcsec	float	The maximum distance (in arcseconds) along the galaxy major axis that the outermost stripes will cover.	required
ymax_arcsec	float	Width of each stripe (in arcseconds) along the galaxy minor axis. Default is the same as xmax_arcsec.	None

Methods:

__init__

__init__(gal_ra_deg, gal_dec_deg, gal_posang_deg, xbin_arcsec, xmax_arcsec, ymax_arcsec=None)

read classmethod

read(filename, **kwargs)

Read (and reconstruct) a StripeMegaTable object from file.

Parameters:

Name	Type	Description	Default
filename	str	Name of the file to read.	required
**kwargs	Any	Keyword arguments to be passed to ~astropy.table.read	{}

Returns:

Type	Description
StripeMegaTable	Reconstructed table instance.

format

format(colnames=None, units=None, formats=None, descriptions=None, ignore_missing=False)

Format table content.

Parameters:

Name	Type	Description	Default
colnames	sequence of str	Names of the columns to keep. Columns in the new table will be ordered according to this parameter.	None
units	sequence	Units to which each kept column should be converted. Items can be either ~astropy.units.Unit objects or their string representations.	None
formats	sequence of str	Format specifiers for each kept column.	None
descriptions	sequence of str	Descriptions of each kept column.	None
ignore_missing	bool	Whether to ignore the error when any key in colnames is missing from the original table (default: False). If True, a column will be added with all NaNs.	False

write

write(filename, keep_metadata=True, add_timestamp=True, **kwargs)

Write table to file.

Parameters:

Name	Type	Description	Default
filename	str	Name of the file to write to.	required
keep_metadata	bool	Whether to keep existing metadata (Default: True)	True
add_timestamp	bool	Whether to add a time stamp in the metadata (Default: True)	True
**kwargs	Any	Additional keyword arguments passed to ~astropy.table.Table.write.	{}

find_coords_in_regions

find_coords_in_regions(ra, dec)

Evaluate region membership for each input coordinate.

Parameters:

Name	Type	Description	Default
ra	array_like	R.A. of the coordinates in question	required
dec	array_like	Declination of the coordinates in question	required

Returns:

Type	Description
ndarray	A boolean array indicating whether each region contains each input coordinate. The shape of this array is: (n_coordinate, n_region).

calc_catalog_stats

calc_catalog_stats(entry, ra, dec, stat_func=None, weight=None, colname='new_col', unit='', **kwargs)

Calculate statistics of a catalog entry within each region.

"Catalog" in this context means a table recording both the (ra, dec) coordinates and other properties of a list of identified objects on the sky. Typical examples: molecular cloud catalogs, HII region catalogs, stellar cluster catalogs.

An example catalog entry: the "molecular cloud size" column in a cloud catalog.

Parameters:

Name	Type	Description	Default
entry	array_like	The catalog entry in question.	required
ra	array_like	RA coordinates of the listed objects.	required
dec	array_like	Dec coordinates of the listed objects.	required
stat_func	callable	A function that accepts an array of values and returns a scalar value (which is the calculated statistics). If 'weight' is not None, this function should also accept a keyword named 'weights', which specifies the statistical weight of each value in the array.	None
weight	array_like	If not None, this keyword should be an ndarray specifying the statistical weight of each row in the catalog. Note that in this case, the broadcasted weight array will be passed to 'stat_func' in a keyword named 'weights'.	None
colname	str	Name of a column in the table to save the output values. Default: 'new_col'	'new_col'
unit	str or `~astropy.units.UnitBase`	Physical unit of the output values (default='').	''
**kwargs	Any	Additional keyword arguments passed to stat_func.	{}

calc_image_stats

calc_image_stats(image, ihdu=0, header=None, stat_func=None, weight=None, colname='new_col', unit='', suppress_error=False, **kwargs)

Calculate statistics of an image within each region.

Parameters:

Name	Type	Description	Default
image	str, bytes, path-like, `~astropy.io.fits.HDUList`,	FITS HDU, or ndarray The image to calculate statistics for.	required
ihdu	int	If 'image' is a str or an HDUList, this keyword should specify which HDU (extension) to use (default=0)	0
header	`~astropy.io.fits.Header`	If 'image' is an ndarray, this keyword should be a FITS header providing the WCS information.	None
stat_func	callable	A function that accepts an array of values, and return a scalar value (which is the calculated statistics). If 'weight' is not None, this function should also accept a keyword named 'weights', which specifies the statistical weight of each value in the array.	None
weight	array_like	If not None, this keyword should be an ndarray specifying the statistical weight of each pixel in the input image. Note that in this case, the broadcasted weight array will be passed to 'stat_func' in a keyword named 'weights'.	None
colname	str	Name of a column in the table to save the output values. Default: 'new_col'	'new_col'
unit	str or `~astropy.units.UnitBase`	Physical unit of the output values (default=''). If unit='header', the 'BUNIT' entry in the header is used.	''
suppress_error	bool	Whether to suppress the error message if 'image' looks like a file but is not found on disk (default=False)	False
**kwargs	Any	Additional keyword arguments passed to stat_func.	{}

create_maps_from_columns

create_maps_from_columns(colnames, header, allow_region_overlap=False)

Create 2D maps from data in columns based on a FITS header.

Parameters:

Name	Type	Description	Default
colnames	sequence of str	Name of the columns to create 2D maps for.	required
header	`~astropy.fits.Header`	FITS header defining the WCS of the output 2D maps.	required
allow_region_overlap	bool	If False (default), an error will be raised when regions overlap (i.e., if any pixel belongs in multiple regions). If True, overlapping regions will be allowed, in which case later rows (regions) will overwrite earlier rows.	False

Returns:

Type	Description
list	List of two-dimensional arrays or quantity arrays built from the requested columns.

ApertureMegaTable

Bases: GeneralRegionTable

Mega-table built from apertures centered on specified locations.

Each aperture corresponds to a row in the table. Once a table is constructed, additional columns can be added by calculating statistics of images within each aperture.

Parameters:

Name	Type	Description	Default
aperture_ra_deg	array_like	Right Ascension of the aperture centers (in degrees).	required
aperture_dec_deg	array_like	Declination of the aperture centers (in degrees).	required
aperture_size_arcsec	float	The angular size of the apertures (in arcseconds).	required
aperture_names	list of str	Names of the apertures.	None

Methods:

__init__

__init__(aperture_ra_deg, aperture_dec_deg, aperture_size_arcsec, aperture_names=None)

read classmethod

read(filename, **kwargs)

Read (and reconstruct) an ApertureMegaTable object from file.

Parameters:

Name	Type	Description	Default
filename	str	Name of the file to read.	required
**kwargs	Any	Keyword arguments to be passed to ~astropy.table.read	{}

Returns:

Type	Description
ApertureMegaTable	Reconstructed table instance.

resample_image

resample_image(image, ihdu=0, header=None, colname='new_col', unit='', suppress_error=False, fill_outside='nearest')

Resample an image at the location of the aperture centers.

The resampling is done by finding the nearest image pixel to each aperture center.

Parameters:

Name	Type	Description	Default
image	str, bytes, path-like, `~astropy.io.fits.HDUList`,	FITS HDU, or ndarray The image to be resampled.	required
ihdu	int	If 'image' is a str or an HDUList, this keyword should specify which HDU (extension) to use (default=0)	0
header	`~astropy.io.fits.Header`	If 'image' is an ndarray, this keyword should be a FITS header providing the WCS information.	None
colname	str	Name of a column in the table to save the output values. Default: 'new_col'	'new_col'
unit	str or `~astropy.units.UnitBase`	Physical unit of the output values (default=''). If unit='header', the 'BUNIT' entry in the header is used.	''
fill_outside	(nearest, float)	The behavior outside the footprint of the input image. If fill_outside='nearest', all seeds outside the footprint are assigned the value of the nearest pixel in the image. Otherwise, all aperture centers outside the image footprint are assigned the value of this keyword.	'nearest'
suppress_error	bool	Whether to suppress the error message if 'image' looks like a file but is not found on disk (default=False)	False

format

format(colnames=None, units=None, formats=None, descriptions=None, ignore_missing=False)

Format table content.

Parameters:

Name	Type	Description	Default
colnames	sequence of str	Names of the columns to keep. Columns in the new table will be ordered according to this parameter.	None
units	sequence	Units to which each kept column should be converted. Items can be either ~astropy.units.Unit objects or their string representations.	None
formats	sequence of str	Format specifiers for each kept column.	None
descriptions	sequence of str	Descriptions of each kept column.	None
ignore_missing	bool	Whether to ignore the error when any key in colnames is missing from the original table (default: False). If True, a column will be added with all NaNs.	False

write

write(filename, keep_metadata=True, add_timestamp=True, **kwargs)

Write table to file.

Parameters:

Name	Type	Description	Default
filename	str	Name of the file to write to.	required
keep_metadata	bool	Whether to keep existing metadata (Default: True)	True
add_timestamp	bool	Whether to add a time stamp in the metadata (Default: True)	True
**kwargs	Any	Additional keyword arguments passed to ~astropy.table.Table.write.	{}

find_coords_in_regions

find_coords_in_regions(ra, dec)

Evaluate region membership for each input coordinate.

Parameters:

Name	Type	Description	Default
ra	array_like	R.A. of the coordinates in question	required
dec	array_like	Declination of the coordinates in question	required

Returns:

Type	Description
ndarray	A boolean array indicating whether each region contains each input coordinate. The shape of this array is: (n_coordinate, n_region).

calc_catalog_stats

calc_catalog_stats(entry, ra, dec, stat_func=None, weight=None, colname='new_col', unit='', **kwargs)

Calculate statistics of a catalog entry within each region.

"Catalog" in this context means a table recording both the (ra, dec) coordinates and other properties of a list of identified objects on the sky. Typical examples: molecular cloud catalogs, HII region catalogs, stellar cluster catalogs.

An example catalog entry: the "molecular cloud size" column in a cloud catalog.

Parameters:

Name	Type	Description	Default
entry	array_like	The catalog entry in question.	required
ra	array_like	RA coordinates of the listed objects.	required
dec	array_like	Dec coordinates of the listed objects.	required
stat_func	callable	A function that accepts an array of values and returns a scalar value (which is the calculated statistics). If 'weight' is not None, this function should also accept a keyword named 'weights', which specifies the statistical weight of each value in the array.	None
weight	array_like	If not None, this keyword should be an ndarray specifying the statistical weight of each row in the catalog. Note that in this case, the broadcasted weight array will be passed to 'stat_func' in a keyword named 'weights'.	None
colname	str	Name of a column in the table to save the output values. Default: 'new_col'	'new_col'
unit	str or `~astropy.units.UnitBase`	Physical unit of the output values (default='').	''
**kwargs	Any	Additional keyword arguments passed to stat_func.	{}

calc_image_stats

calc_image_stats(image, ihdu=0, header=None, stat_func=None, weight=None, colname='new_col', unit='', suppress_error=False, **kwargs)

Calculate statistics of an image within each region.

Parameters:

Name	Type	Description	Default
image	str, bytes, path-like, `~astropy.io.fits.HDUList`,	FITS HDU, or ndarray The image to calculate statistics for.	required
ihdu	int	If 'image' is a str or an HDUList, this keyword should specify which HDU (extension) to use (default=0)	0
header	`~astropy.io.fits.Header`	If 'image' is an ndarray, this keyword should be a FITS header providing the WCS information.	None
stat_func	callable	A function that accepts an array of values, and return a scalar value (which is the calculated statistics). If 'weight' is not None, this function should also accept a keyword named 'weights', which specifies the statistical weight of each value in the array.	None
weight	array_like	If not None, this keyword should be an ndarray specifying the statistical weight of each pixel in the input image. Note that in this case, the broadcasted weight array will be passed to 'stat_func' in a keyword named 'weights'.	None
colname	str	Name of a column in the table to save the output values. Default: 'new_col'	'new_col'
unit	str or `~astropy.units.UnitBase`	Physical unit of the output values (default=''). If unit='header', the 'BUNIT' entry in the header is used.	''
suppress_error	bool	Whether to suppress the error message if 'image' looks like a file but is not found on disk (default=False)	False
**kwargs	Any	Additional keyword arguments passed to stat_func.	{}

create_maps_from_columns

create_maps_from_columns(colnames, header, allow_region_overlap=False)

Create 2D maps from data in columns based on a FITS header.

Parameters:

Name	Type	Description	Default
colnames	sequence of str	Name of the columns to create 2D maps for.	required
header	`~astropy.fits.Header`	FITS header defining the WCS of the output 2D maps.	required
allow_region_overlap	bool	If False (default), an error will be raised when regions overlap (i.e., if any pixel belongs in multiple regions). If True, overlapping regions will be allowed, in which case later rows (regions) will overwrite earlier rows.	False

Returns:

Type	Description
list	List of two-dimensional arrays or quantity arrays built from the requested columns.

TessellMegaTable

Bases: VoronoiTessTable

Mega-table built from a tessellation of a galaxy's sky footprint.

Each tile in the tessellation maps to a row in the table. Once a table is constructed, additional columns can be added by calculating statistics of images within each tile, or by resampling images at the center of each tile.

Parameters:

Name	Type	Description	Default
center_ra_deg	float	Right Ascension of the FoV center (in degrees). This also determines the location of the central tile.	required
center_dec_deg	float	Declination of the FoV center (in degrees). This also determines the location of the central tile.	required
fov_radius_arcsec	float	Radius of the FoV covered by the tessellation (in arcsecs). This determines the overall extent of the tessellation.	required
tile_size_arcsec	float	The angular size of the tiles (defined as the spacing between adjacent tile centers; in arcseconds).	required
tile_shape	(hexagon, square)	The shape of the tiles that form the tessellation. Default: 'hexagon', in which case hexagonal tiles are used.	'hexagon'

Methods:

read classmethod

read(filename, **kwargs)

Read (and reconstruct) a TessellMegaTable object from file.

Parameters:

Name	Type	Description	Default
filename	str	Name of the file to read.	required
**kwargs	Any	Keyword arguments to be passed to ~astropy.table.read	{}

Returns:

Type	Description
TessellMegaTable	Reconstructed table instance.

show_tiles_on_sky

show_tiles_on_sky(ax=None, image=None, ffigkw=None, **scatterkw)

Plot tile centers on an image or Matplotlib axes.

Parameters:

Name	Type	Description	Default
ax	`~matplotlib.axes.Axes`	Axes on which to plot the tile centers when image is not supplied. If omitted, the current axes are created and used.	None
image	Any	Image-like input accepted by aplpy.FITSFigure. When provided, the markers are overplotted on that image.	None
ffigkw	dict	Keyword arguments passed to aplpy.FITSFigure.	None
**scatterkw	Any	Keyword arguments passed to the marker plotting call.	{}

Returns:

Type	Description
Any	aplpy.FITSFigure when image is supplied, otherwise the Matplotlib axes containing the scatter plot.

format

format(colnames=None, units=None, formats=None, descriptions=None, ignore_missing=False)

Format table content.

Parameters:

Name	Type	Description	Default
colnames	sequence of str	Names of the columns to keep. Columns in the new table will be ordered according to this parameter.	None
units	sequence	Units to which each kept column should be converted. Items can be either ~astropy.units.Unit objects or their string representations.	None
formats	sequence of str	Format specifiers for each kept column.	None
descriptions	sequence of str	Descriptions of each kept column.	None
ignore_missing	bool	Whether to ignore the error when any key in colnames is missing from the original table (default: False). If True, a column will be added with all NaNs.	False

write

write(filename, keep_metadata=True, add_timestamp=True, **kwargs)

Write table to file.

Parameters:

Name	Type	Description	Default
filename	str	Name of the file to write to.	required
keep_metadata	bool	Whether to keep existing metadata (Default: True)	True
add_timestamp	bool	Whether to add a time stamp in the metadata (Default: True)	True
**kwargs	Any	Additional keyword arguments passed to ~astropy.table.Table.write.	{}

find_coords_in_regions

find_coords_in_regions(ra, dec, fill_value=-1)

Match coordinates to the nearest Voronoi tile.

Parameters:

Name	Type	Description	Default
ra	array_like	R.A. of the coordinates in question	required
dec	array_like	Declination of the coordinates in question	required
fill_value	int	The index value to return for input coordinates that have no matched regions (default: -1).	-1

Returns:

Type	Description
ndarray	An index array indicating which tile each input coordinate belongs to. The length of this array equals the number of input coordinates.

calc_catalog_stats

calc_catalog_stats(entry, ra, dec, stat_func=None, weight=None, colname='new_col', unit='', **kwargs)

Calculate statistics of a catalog entry within each region.

"Catalog" in this context means a table recording both the (ra, dec) coordinates and other properties of a list of identified objects on the sky. Typical examples: molecular cloud catalogs, HII region catalogs, stellar cluster catalogs.

An example catalog entry: the "molecular cloud size" column in a cloud catalog.

Parameters:

Name	Type	Description	Default
entry	array_like	The catalog entry in question.	required
ra	array_like	RA coordinates of the listed objects.	required
dec	array_like	Dec coordinates of the listed objects.	required
stat_func	callable	A function that accepts an array of values and returns a scalar value (which is the calculated statistics). If 'weight' is not None, this function should also accept a keyword named 'weights', which specifies the statistical weight of each value in the array.	None
weight	array_like	If not None, this keyword should be an ndarray specifying the statistical weight of each row in the catalog. Note that in this case, the broadcasted weight array will be passed to 'stat_func' in a keyword named 'weights'.	None
colname	str	Name of a column in the table to save the output values. Default: 'new_col'	'new_col'
unit	str or `~astropy.units.UnitBase`	Physical unit of the output values (default='').	''
**kwargs	Any	Additional keyword arguments passed to stat_func.	{}

calc_image_stats

calc_image_stats(image, ihdu=0, header=None, stat_func=None, weight=None, colname='new_col', unit='', suppress_error=False, **kwargs)

Calculate statistics of an image within each region.

Parameters:

Name	Type	Description	Default
image	str, bytes, path-like, `~astropy.io.fits.HDUList`,	FITS HDU, or ndarray The image to calculate statistics for.	required
ihdu	int	If 'image' is a str or an HDUList, this keyword should specify which HDU (extension) to use (default=0)	0
header	`~astropy.io.fits.Header`	If 'image' is an ndarray, this keyword should be a FITS header providing the WCS information.	None
stat_func	callable	A function that accepts an array of values, and return a scalar value (which is the calculated statistics). If 'weight' is not None, this function should also accept a keyword named 'weights', which specifies the statistical weight of each value in the array.	None
weight	array_like	If not None, this keyword should be an ndarray specifying the statistical weight of each pixel in the input image. Note that in this case, the broadcasted weight array will be passed to 'stat_func' in a keyword named 'weights'.	None
colname	str	Name of a column in the table to save the output values. Default: 'new_col'	'new_col'
unit	str or `~astropy.units.UnitBase`	Physical unit of the output values (default=''). If unit='header', the 'BUNIT' entry in the header is used.	''
suppress_error	bool	Whether to suppress the error message if 'image' looks like a file but is not found on disk (default=False)	False
**kwargs	Any	Additional keyword arguments passed to stat_func.	{}

create_maps_from_columns

create_maps_from_columns(colnames, header, allow_region_overlap=False)

Create 2D maps from data in columns based on a FITS header.

Parameters:

Name	Type	Description	Default
colnames	sequence of str	Name of the columns to create 2D maps for.	required
header	`~astropy.fits.Header`	FITS header defining the WCS of the output 2D maps.	required
allow_region_overlap	bool	If False (default), an error will be raised when regions overlap (i.e., if any pixel belongs in multiple regions). If True, overlapping regions will be allowed, in which case later rows (regions) will overwrite earlier rows.	False

Returns:

Type	Description
list	List of two-dimensional arrays or quantity arrays built from the requested columns.

resample_image

resample_image(image, ihdu=0, header=None, colname='new_col', unit='', suppress_error=False, fill_outside='nearest')

Resample an image at the location of the Voronoi seeds.

The resampling is done by finding the nearest pixel to the location of each seed in the image.

Parameters:

Name	Type	Description	Default
image	str, bytes, path-like, `~astropy.io.fits.HDUList`,	FITS HDU, or ndarray The image to be resampled.	required
ihdu	int	If 'image' is a str or an HDUList, this keyword should specify which HDU (extension) to use (default=0)	0
header	`~astropy.io.fits.Header`	If 'image' is an ndarray, this keyword should be a FITS header providing the WCS information.	None
colname	str	Name of a column in the table to save the output values. Default: 'new_col'	'new_col'
unit	str or `~astropy.units.UnitBase`	Physical unit of the output values (default=''). If unit='header', the 'BUNIT' entry in the header is used.	''
fill_outside	(nearest, float)	The behavior outside the footprint of the input image. If fill_outside='nearest', all seeds outside the footprint are assigned the value of the nearest pixel in the image. Otherwise, all seeds outside the image footprint are assigned the value of this keyword.	'nearest'
suppress_error	bool	Whether to suppress the error message if 'image' looks like a file but is not found on disk (default=False)	False