Usage Requirements: TOPCAT requires Java environment to run. It can be used with or without an internet connection, but an internet connection is required if you want to use its database searching capabilities.
From their website "TOPCAT is an interactive graphical viewer and editor for tabular data. Its aim is to provide most of the facilities that astronomers need for analysis and manipulation of source catalogues and other tables, though it can be used for non-astronomical data as well. It understands a number of different formats, both astronomically important (FITS, VOTable, CDF) and general purpose (CSV, ASCII, Parquet), and more formats can be added. It is especially good at interactive exploration of large (multi-million row, lots of columns) tables.
It handles the following file types (list from their website): FITS BINTABLE (binary table) or TABLE (ASCII table) extensions, VOTables in any of the format variants (TABLEDATA, FITS, BINARY, BINARY2) or versions, ASCII tables in a number of variations, CDF files, Comma-Separated Values (CSV), Enhanced Character-Separated Values (ECSV), Results of SQL queries on relational databases, Parquet files, IPAC format, AAS Machine-Readable Tables, HAPI streams, Feather files, GBIN files.
It offers a variety of ways to view and analyse tables, including a browser for the cell data themselves, viewers for information about table and column metadata, and facilities for sophisticated interactive 1-, 2-, 3- and higher-dimensional visualisation, calculating statistics and joining tables using flexible matching algorithms. Using a powerful and extensible Java-based expression language new columns can be defined and row subsets selected for separate analysis. Table data and metadata can be edited and the resulting modified table can be written out in a wide range of output formats.
It is a stand-alone application which works quite happily with no network connection. However, because it uses Virtual Observatory (VO) standards, it can cooperate smoothly with other tools, services and datasets in the VO world and beyond.
The program is written in pure Java (except for optional Parquet I/O libraries) and available under the GNU General Public Licence, though some of the library code is LGPL. Source code is available at https://github.com/Starlink/starjava. It has been developed mostly in the UK within various UK and Euro-VO projects (Starlink, AstroGrid, VOTech, AIDA, GAVO, GENIUS, DPAC) and under PPARC and STFC grants. Its underlying table processing facilities are provided by the related packages STIL and STILTS.
In my experience, it is an excellent resource for handling large data tables, and it is very straightforward to use.
Contributor: Prof. Jeffrey Gerber, Purdue University
Click here
to access this resource