This section describes the messages which TOPCAT can transmit to other
tools which understand the SAMP protocol, and how to cause them
to be sent.
In most cases you can choose two ways to transmit a message
from TOPCAT:
Below is a list of places you can cause TOPCAT to transmit messages.
The SAMP MTypes message IDs
are listed along with the descriptions;
unless you are a tool developer you can probably ignore these.
- Transmit Table
- The Control Window's
Interop menu provides
Broadcast Table and Send Table
options which cause the currently selected table to be transmitted
to other listening applications.
They are invited to load the table in its current
("apparent") form.
The Broadcast action is also available in the toolbar.
SAMP MTypes:
table.load.votable
or
table.load.fits
- Transmit Subset
- The Subset Window's
Interop menu
contains Broadcast Subset and Send Subset
options.
These cause the selected subset to be sent to other listening applications
(these actions are only available when one of the subsets is currently
selected).
Applications are invited to highlight the rows corresponding to that subset.
Note this will only have an effect if the other application(s) are
displaying the table that this subset relates to. This will be
the case in one of two situations:
(1) the table has been loaded from the same URL/filename by the
other tool(s) or
(2) the other tool(s) have acquired the table because it has
already been broadcast using SAMP.
Also, whenever a new subset is created, for instance by entering an
algebraic expression or tracing out a region on a plot
(see Section 3.1.1),
you have the option of transmitting the subset directly to one or all
listening applications as an alternative to adding the new subset to
the table's subset list.
SAMP MType: table.select.rowList
- Transmit Row
- The ControlWindow has a
Broadcast Row checkbox by the
Activation Action selector.
If this is selected, then any time you activate a row
(e.g. by clicking on the corresponding point in a plot)
other applications who are looking at the same table are invited
to highlight that row in their copy of the table.
As for Transmit Subset above, this will only have an
effect if the other application(s) are displaying the same table.
A similar facility is available as the Transmit Row
option in the
Activation Actions
window itself - the checkbox is just a convenience for a commonly-used
option.
SAMP MType: table.highlight.row
- Transmit Coordinates
- Another
Activation Action
is Transmit Coordinates.
In this case when you activate a row (e.g. by clicking on the
corresponding point in a plot)
other applications are invited to point out the
sky position corresponding to the row which is activated,
for instance by placing a cursor over it.
The table columns which correspond to Right Ascension and Declination
must be selected for this to work.
SAMP MType: coord.pointAt.sky
- Transmit Image
- The Density Plot
produces a 2-d histogram which is actually an image.
Its Interop menu provides
Broadcast Image and Send Image options
which will send this (as a FITS image) to other applications
which can display it in some way.
This is a useful supplement to the facilities of the Density Plot
window, since it doesn't have very sophisticated image display
features (variable colour maps, contour plots etc).
Also, the View URL as Image
Activation Action
option allows you to identify a column which contains an image URL
and to send it to a suitable image viewer or viewers.
SAMP MType: image.load.fits
- Transmit Spectrum
- The View URL as Spectrum
Activation Action
option allows you to identify a column which contains a spectrum URL
and to send it to a suitable spectrum viewer or viewers.
SAMP MType: spectrum.load.ssa-generic
- Transmit Resource List
- The Registry Query Panel
present in most of the Virtual Observatory windows allows
you to send lists of VO registry resource identifiers to other
applications which can make use of them.
SAMP MTypes: voresource.loadlist.cone
,
voresource.loadlist.siap
,
voresource.loadlist.ssap