GTable¶

class grizli.utils.GTable(data=None, masked=False, names=None, dtype=None, meta=None, copy=True, rows=None, copy_indices=True, units=None, descriptions=None, **kwargs)[source]¶

Bases: Table

Extend Table class with more automatic IO and other helper methods.

Methods Summary

`add_aladdin`([rd_cols, fov, size, default_view])	Add AladinLite DIV column to the table
`gread`(file[, sextractor, format])	Assume `ascii.commented_header` by default
`gwrite`(output[, format])	Assume a format for the output table
`match_to_catalog_sky`(other[, self_radec, ...])	Compute `SkyCoord` projected matches between two `GTable` tables.
`match_triangles`(other[, self_wcs, x_column, ...])	Match sources between two catalogs using triangles
`parse_radec_columns`(self[, rd_pairs])	Parse column names for RA/Dec and set to `degree` units if not already set
`write_sortable_html`(output[, ...])	Wrapper around `write(format='jsviewer')`.

Methods Documentation

add_aladdin(rd_cols=['ra', 'dec'], fov=0.5, size=(400, 200), default_view='P/DSS2/color')[source]¶

Add AladinLite DIV column to the table

Parameters

rd_colslist, optional: The column names in self that contain the right ascension and declination coordinates of the sources. Default is [“ra”, “dec”].
fovfloat, optional: The field of view in degrees. Default is 0.5.
sizetuple, optional: The size of the DIVs in pixels (width, height). Default is (400, 200).
default_viewstr, optional: The default view of the AladinLite image. Default is “P/DSS2/color”.

classmethod gread(file, sextractor=False, format=None)[source]¶

Assume ascii.commented_header by default

Parameters

sextractorbool: Use format='ascii.sextractor'.
formatNone or str: Override format passed to read.

Returns

tabTable: Table object

gwrite(output, format='ascii.commented_header')[source]¶

Assume a format for the output table

Parameters

outputstr: Output filename
formatstr: Format string passed to write.

match_to_catalog_sky(other, self_radec=None, other_radec=None, nthneighbor=1, get_2d_offset=False)[source]¶

Compute SkyCoord projected matches between two GTable tables.

Parameters

otherTable, GTable, or list.

Other table to match positions from.

self_radec, other_radecNone or [str, str]

Column names for RA and Dec. If None, then try the following pairs (in this order):

>>> rd_pairs = OrderedDict()
>>> rd_pairs['ra'] = 'dec'
>>> rd_pairs['ALPHA_J2000'] = 'DELTA_J2000'
>>> rd_pairs['X_WORLD'] = 'Y_WORLD'

nthneighborint

See match_to_catalog_sky.

get_2d_offsetbool, optional

If True, compute the 2D offset between the matched coordinates.

Returns

idxint array

Indices of the matches as in

>>> matched = self[idx]
>>> len(matched) == len(other)

drfloat array

Projected separation of closest match.

Examples

>>> import astropy.units as u

>>> ref = GTable.gread('input.cat')
>>> gaia = GTable.gread('gaia.cat')
>>> idx, dr = ref.match_to_catalog_sky(gaia)
>>> close = dr < 1*u.arcsec

>>> ref_match = ref[idx][close]
>>> gaia_match = gaia[close]

match_triangles(other, self_wcs=None, x_column='X_IMAGE', y_column='Y_IMAGE', mag_column='MAG_AUTO', other_ra='X_WORLD', other_dec='Y_WORLD', pixel_index=1, match_kwargs={}, pad=100, show_diagnostic=False, auto_keep=3, maxKeep=10, auto_limit=3, ba_max=0.99, scale_density=10)[source]¶

Match sources between two catalogs using triangles

Parameters

selfGTable: The first catalog to match.
otherTable or GTable or list: The second catalog to match.
self_wcsWCS, optional: The WCS object associated with the first catalog. If provided, the positions in self will be transformed to pixel coordinates using this WCS before matching.
x_columnstr, optional: The column name in self that contains the x-coordinates of the sources. Default is “X_IMAGE”.
y_columnstr, optional: The column name in self that contains the y-coordinates of the sources. Default is “Y_IMAGE”.
mag_columnstr, optional: The column name in self that contains the magnitudes of the sources. Default is “MAG_AUTO”.
other_rastr, optional: The column name in other that contains the right ascension coordinates of the sources. Default is “X_WORLD”.
other_decstr, optional: The column name in other that contains the declination coordinates of the sources. Default is “Y_WORLD”.
pixel_indexint, optional: The pixel index convention to use when transforming the positions from world coordinates to pixel coordinates. Default is 1.
match_kwargsdict, optional: Additional keyword arguments to pass to the match_catalog_tri function.
padfloat, optional: The padding in pixels to apply to the bounding box of the second catalog. Default is 100.
show_diagnosticbool, optional: If True, a diagnostic plot showing the matched sources will be created. Default is False.
auto_keepint, optional: The number of matched sources to keep when performing the automatic matching. Default is 3.
maxKeepint, optional: The maximum number of matched sources to keep. Default is 10.
auto_limitint, optional: The maximum number of sources to use when performing the automatic matching. Default is 3.
ba_maxfloat, optional: The maximum axis ratio allowed when performing the automatic matching. Default is 0.99.
scale_densityfloat, optional: The scaling factor to apply to the number of sources in the second catalog when matching the surface densities of the two catalogs. Default is 10.

Returns

match_ixndarray: The indices of the matched sources in self and other.
tfndarray: The transformation matrix that maps the positions in self to the positions in other.
dxndarray: The residual offsets between the matched sources in self and other after applying the transformation.
rmsfloat: The root-mean-square residual of the matched sources.
figFigure, optional: The diagnostic plot showing the matched sources. Only returned if show_diagnostic is True.

static parse_radec_columns(self, rd_pairs=None)[source]¶

Parse column names for RA/Dec and set to degree units if not already set

Parameters

rd_pairsOrderedDict or None

Pairs of {ra:dec} names to search in the column list. If None, then uses the following by default.

>>> rd_pairs = OrderedDict()
>>> rd_pairs['ra'] = 'dec'
>>> rd_pairs['ALPHA_J2000'] = 'DELTA_J2000'
>>> rd_pairs['X_WORLD'] = 'Y_WORLD'

NB: search is performed in order of rd_pairs.keys() and stops if/when a match is found.

Returns

rd_pair[str, str]: Column names associated with RA/Dec. Returns False if no column pairs found based on rd_pairs.

write_sortable_html(output, replace_braces=True, localhost=True, max_lines=50, table_id=None, table_class='display compact', css=None, filter_columns=[], buttons=['csv'], toggle=True, use_json=False, with_dja_css=False, timestamp=True)[source]¶

Wrapper around write(format='jsviewer').

Parameters

outputstr: Output filename.
replace_bracesbool: Replace ‘<’ and ‘>’ characters that are converted automatically from “<>” by the write method. There are parameters for doing this automatically with write(format='html') but that don’t appear to be available with write(format='jsviewer').
localhostbool: Use local JS files. Otherwise use files hosted externally.
max_linesint, optional: Maximum number of lines to display in the table. Default is 50.
table_idstr, optional: ID attribute for the HTML table element.
table_classstr, optional: Class attribute for the HTML table element. Default is “display compact”.
cssstr, optional: Additional CSS styles to apply to the table.
filter_columnslist, optional: Add option to limit min/max values of column data.
buttonslist, optional: Add buttons for exporting data. Allowed options are ‘copy’, ‘csv’, ‘excel’, ‘pdf’, ‘print’.
togglebool, optional: Add links at top of page for toggling columns on/off.
use_jsonbool, optional: Write the data to a JSON file and strip out of the HTML header. Use this for large datasets or if columns include rendered images.
with_dja_cssbool, optional: Include additional CSS styles for Django admin interface.
timestampbool, optional: Add a timestamp to the output file.

Navigation

GTable¶