Next Previous Up Contents
Next: Internal Match Action box
Up: Other Windows
Previous: Output Rows Selector Box
Internal Match Window
The Internal Match Window allows you to perform matching between
rows of the same table, grouping rows that have the same or similar
values in specified columns and producing a new table as a result.
It can be obtained by using the Internal Match
(
) button in the Control Window
toolbar or Joins menu.
You might want to use this functionality to remove all rows which
refer to the same object from an object catalogue,
or to ensure that only one entry exists for each object,
or to identify groups of several "nearby" objects in some way.
The result is created from the Apparent
versions of the tables being joined, so that any row subsets,
hidden columns, or sorts currently in force will be reflected in the
output.
Progress information on the match, which may take some time,
is provided in the logging window and by a progress bar at the bottom
of the window. When it is completed, you will be informed by a
popup window which indicates that a new table has been created.
This table will be added to the list in the Control Window and can
be examined, manipulated and saved like any other.
The window has the following parts:
-
Match Criteria box
- Allows you to define what counts as a match between two rows
(the same as for pair matching).
-
Column Selection box
- Allows you to select which table to operate on and which columns
supply the matching coordinates
(the same as for pair matching).
-
Match Action box
- Allows you to select what will be done (what new table will be
created) when the matching groups of rows have been identified.
-
Log Panel
- Displays progress as the match is taking place. The progress bar
at the bottom of the window also provides an indication of how
far through each stage processing has got.
-
Control buttons
- The Go button starts the search when you are
happy with the selections that you have made, and the
Stop button interrupts it midway if you decide
you no longer want the results (closing the Match Window also
interrupts the calculation).
Next Previous Up Contents
Next: Internal Match Action box
Up: Other Windows
Previous: Output Rows Selector Box
TOPCAT - Tool for OPerations on Catalogues And Tables
Starlink User Note253
TOPCAT web page:
http://www.starlink.ac.uk/topcat/
Author email:
m.b.taylor@bristol.ac.uk