open.catalogue: Open and Read, or Generate, a Catalogue

In AngusWright/LAMBDAR: Measure galaxy fluxes from an arbitrary FITS image using input aperture locations and dimensions

Open and Read, or Generate, a Catalogue

Description

__This function is not designed to be called directly, but rather is an internal function to measure.fluxes__

Open and read an input catalogue for the measure.fluxes procedure, or generate one from a segmentation image.

Usage

open.catalogue(outenv = parent.env(environment()), save.table=FALSE, env = NULL)
generate.catalogue(outenv = parent.env(environment()), save.table=FALSE, env = NULL)

Arguments

env	environment; the environment containing the parameters used in ‘measure.fluxes’
outenv	environment; the environment where the returned values are to be stored. If not provided, outenv defaults to the input env.
save.table	logical; Should a copy of the table be saved to the environment (for fast reading in subsequent loops).

Details

The Catalogue is expected to contain a series of columns that will vary depending on the input parameters selected, and whose exact labels can be specified in the parameter file. For all runs of LAMBDAR, it is expected that the user catalogue specifies columns containing: Object IDs: Can be strings or numeric Object RAs: Expected to be in Decimal Degrees Object Decs: Expected to be in Decimal Degrees

In addition to these, if the user has not specified that all objects should be forced to be point sources then the following additional columns must also be specified: Object Aperture SemiMajor Axis: Expected to be in arcseconds Object Aperture SemiMinor Axis: Expected to be in arcseconds Object Aperture orientation: Expected to be in decimal degrees, and in N90E0. However can be specified in N0E90 if the AngularOffset parameter is set to 1 in the parameter file.

If the user has asked for Contaminants to be deblended and removed from the final catalogue (by specifying the RemoveContams parameter as 1) then it is expected that there is a boolean 1/0 column provided, containing flags for which objects are contaminants [1], or main objects [0].

Finally, the user may optionally provide a column containing object weightings in conjunction with any other series of parameters. The weightings can be specified in terms of flux, magnitude, or scale, as determined by the users specification of the ‘FluxWgtType’ parameter.

If the catalogue is being generated from a segmentation image, then the function creates quasi-aperture parameters from the size of the segmentation map for each source. These are used in creating aperture stamps, so that the stamps are an appropriate size for each source. The program will subsequently use the make.segmentation.apertures function to assign each source's segmentation map as an aperture.

Value

NULL; The procedure assigns variables into the parameter environment ‘outenv’.

Author(s)

Angus H Wright ICRAR [e-mail]

AngusWright/LAMBDAR documentation built on May 12, 2022, 1:49 a.m.