Valid for Release 0 (CASA Version 3.0.0).See the Release Notes for more instructions and known issues.
This quick reference is intended to get the user up an runningquickly with CASA. The user should refer to the CASA Data AnalysisCookbook for more detailed explanations of this material,and also if problems are encountered.
NOTE: There is also a CASAGuides Wiki Pagethat contains much of the same information as this page.
Installing CASAYou should first obtain and install CASA.It is available via your my.nrao.edu portal at NRAO. You may need to register if you don't have an my.nrao.edu account yet.
In the following, we will assume that the installation was successful.
Before Starting CASAIf you have done a default installation under Linux using rpms, or on the Mac with the CASA application, then there should be a shscript called casapy in the /usr/bin area which is inyour path. This shell will set up its environment and run the versionof casapy that it points to. If this is how you set up thesystem, then you need to nothing further and can run casapy.
Depending on your setup, there may be other specially built versionsavailable. For example at the NRAO AOC, the ``stable build'' can bestarted by running ``casapy-test'', e.g.
/usr/bin/casapy-test
Before starting up casapy, you should set or reset anyenvironment variables needed, as CASA will adopt these on startup. Forexample, the PAGER environment variable determines how help isdisplayed in the CASA terminal window. We recommend using thecat option for most users, as this workssmoothly both interactively and in scripts.In bash:
PAGER=cat
or in csh or tcsh:
setenv PAGER cat
The actions of these are as if you were using the equivalent Unixshell command to view the help material.
Note that the path to the CASA installation, which containsthe casainit shell scripts and data repository, will also depend upon the installation. With a default installation under Linux thiswill probably be in
/usr/lib/casapy/
while in a Mac OSX default install it will likely be aself-contained application (in the Applications area)with the data repository in /opt/casa/
You can find the location after initialization by looking atthe
CASAPATHenvironment variable. You can findit within
casapyby typing:
pathname=os.environ.get('CASAPATH').split()[0]print pathname
For example, atthe NRAO AOC, the current release is executed as
/usr/bin/casapy
and uses the pathname to
/usr/lib/casapy/23.0.6654-001
Sometimes, you will have multiple non-defaultversions (for example, various development versions). For example at theNRAO AOC, the ``stable build'' is in /home/casa.Then, to use this version you invoke the appropriate casainitshell script, e.g.
. /home/casa/casainit.sh (bash or Bourne)
or
source /home/casa/casainith.csh (csh or tcsh).
Generally, you will want to start CASA from a working directoryfor your project. Just make this directory andcd to it. As usual, things go better if this is ona disk local to your machine.
After having run the appropriate casainit script, CASA is started bytyping casapy on the UNIX command line, e.g.
casapy
On the Mac, you can also double-click the CASA Application tostart. It will then start up in your home area.
After startup information, you should get an IPython CASA <1>:command prompt in thexterm window where you started CASA. CASA will take approximately 10seconds to initialize at startup in a new working directory;subsequent startups are faster. CASA is active when you get aCASA <1>: prompt in the command line interface. You will alsosee a logger GUI appear on your Desktop (usually near theupper left).
You also have the option of starting CASA without the
logger, forexample if you are running remotely in a terminal window withoutan X11 connection, or if you just do not want to see the logger GUI.In this case use the
--nologgeroption:
casapy --nologgerThe logger messages will still go into the
casapy.logfile.If you want to see these at your terminal, use the
--log2termoption also:
casapy --nologger --log2termYou can exit CASA by typing quit, %exit, orCTRL-D at the casapy prompt.If you don't want to see the question "Do you really want to exit[y]/n?", then just type Exit and CASA will stop right then and there.
What If Something Goes Wrong?First, always check that your inputs are correct; use
inp <taskname>
Next, check the inline documentation using the "pdoc" facility:
pdoc <taskname>
or
pdoc par.<parameter_name>
to review the allowed parameters. For example,
pdoc par.selectdata
will give guidance on the use of this parameter (and in thiscase its sub-parameters).
If something has gone wrong and you want to stop what is executing,then typing CNTL-C will usually cleanly abort the application.Alert: Note that you will likely lose contact with thelogger GUI if you have one, so you will then want to restart CASA.
If CASA crashes, then usuallyrestarting casapy is sufficient to get you going again. Note that theremay be spawned subprocesses still running, such as the casaviewer or the logger. These can be dismissed manuallyin the usual manner. After a crash, there may also be hiddenprocesses. You can find these by listing processes, e.g. in linux:
ps -elf | grep casa
or on MacOSX (or other BSD Unix):
ps -aux | grep casa
You can then kill these, for example using the Unix killor killall commands. This may be necessary if you are runningremotely using ssh, as you cannot logout until all yourbackground processes are terminated. For example,
killall ipcontroller
or
killall Python
will terminate the most common post-crash zombies.
See the CASA Data AnalysisCookbook.
Copyright © 1995-2007 Associated Universities Inc.,Washington, D.C.
This code is available under the terms of the GNU General Public Lincense
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