This manual aims to give detailed tutorial and reference documentation on most aspects of TOPCAT's capabilities, and reading it is an excellent way to learn about the program. However, it's quite a fat document, and if you feel you've got better things to do with your time than read it all, you should be able to do most things by playing around with the software and dipping into the manual (or equivalently the online help) when you can't see how to do something or the program isn't behaving as expected. This section provides a short introduction for the impatient, explaining how to get started.
To start the program, you will probably type topcat or
something like
java -jar topcat-full.jar (see Section 10 for
more detail). To view a table that you have on disk, you can either
give its name on the command line or load it using the Load
button from the GUI.
FITS, VOTable, ECSV, CDF, PDS4, feather, Parquet and GBIN files
are recognised automatically;
if your data is in another format such as ASCII (see Section 4.1.1)
you need to tell the program (e.g. -f ascii on the command line).
If you just want to try the program out, topcat -demo will
start with a couple of small tables for demonstration purposes.
The first thing that you see is the Control Window. This has a list of the loaded table(s) on the left. If one of these is highlighted by clicking on it, information about it will be shown on the right; some of this (table name, sort order) you can change here. Along the top is a toolbar with a number of buttons, most of which open up new windows. These correspond to some of the things you might most often want to do in TOPCAT, and fall into a few groups:
The menus provide alternative ways to open up these windows,
and also list a number of other, less commonly-used, options.
The Help () button appears in most windows -
if you click it a help browser will be displayed showing an appropriate
part of this manual.
The Help menu gives you a few
more options along the same lines, including displaying the help
information in your usual web browser rather than in TOPCAT's (somewhat
scrappy) help viewer.
All the windows follow roughly this pattern. For some of the toolbar
buttons you can probably guess what they do from their icons,
for others probably not - to find out
you can hover with the mouse to see the tooltip,
look in the menus, read the manual, or just push it and see.
Some of the windows allow you to make changes of various sorts to the tables, such as performing sorts, selecting rows, modifying data or metadata. None of these affect the table on disk (or database, or wherever), but if you subsequently save the table the changes will be reflected in the table that you save.
A notable point to bear in mind concerns memory.
TOPCAT is fairly efficient in use of memory, but in some cases when
dealing with large tables you might see an OutOfMemoryError.
It is usually possible to work round this by using the
-XmxNNNM
flag on startup - see Section 10.2.2.
Finally, if you have queries, comments or requests about the software, and they don't appear to be addressed in the manual, consult the TOPCAT web page, use the topcat-user mailing list, or contact the author - user feedback is always welcome.