TOPCAT is an interactive graphical viewer and editor for tabular data. Although a general purpose tool capable of handling large and sparse datasets with

correlation In statistics, correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data. Although in the broadest sense, "correlation" may indicate any type of association, in statisti ...

functionality its specialist application area is

astronomy Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest ...

and it was initially designed to support

virtual observatories Virtual may refer to: * Virtual (horse), a thoroughbred racehorse * Virtual channel, a channel designation which differs from that of the actual radio channel (or range of frequencies) on which the signal travels * Virtual function, a programmi ...

. It is able to handle several digital file formats including

FITS Flexible Image Transport System (FITS) is an open standard defining a digital file format useful for storage, transmission and processing of data: formatted as multi-dimensional arrays (for example a 2D image), or tables. FITS is the most comm ...

which is in common use in astronomy. The Acronym ''TOPCAT'' derives from ''Tool for OPerations on Catalogues And Tables''.

History

The project was initially developed by Mark Taylor, an astrophysicist from the

University of Bristol The University of Bristol is a Red brick university, red brick Russell Group research university in Bristol, England. It received its royal charter in 1909, although it can trace its roots to a Society of Merchant Venturers, Merchant Venturers' sc ...

in 2003. Taylor acknowledges inspiration for some features from ''Mirage'' from

Bell Labs Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by mult ...

and ''VOPlot'' from VO-India. Initially funded from the Starlink Project it has been funded by various other projects since.

Features

Written in

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...

, TOPCAT can be used both standalone and within a web browser. It is suitable for use as a graphical viewer and data editor of tabular data from FITS and other sources. Muna, in his 2016 paper "Introducing Nightlight: A New FITS Viewer", observes tha
SAOImage DS9
TOPCAT an
Fv
are the most common tools used to view FITS files. VisIVO is an alternative tool for working with virtual observatories. While TOPCAT is unable to visualise catalogues as a set of vectors it does have capabilities to explore correlations in two and three dimensional scatter plots.

STILTS

The STILTS application complements TOPCAT with similar capabilities but is considered a steeper learning curve, however STILTS does have the advantage of being able to be scripted.

Applications

TOPCAT is used in training for use of

, including access via the

Astronomical Data Query Language Astronomical Data Query Language (ADQL) is a language for astronomical data query based on SQL 92. Overview ADQL is a specialized variant of the SQL query language adapted for accessing the astronomical datasets of the virtual observatory, via ...

(ADQL). Applications using TOPCAT include MultiDark, a database for results from cosmological simulations.

History

Features

STILTS

Applications

References

Sources

External links