ThingsToTry

Things to try with Timba

NB: this is out of date.

Some "simple" test trees

To start the MEQ browser, run LOFAR/installed/current/libexec/python/meqbrowser.py(or LOFAR/Timba/PyApps/src/meqbrowser.py, whichever's handier).

In theory, you can just run leave the browser running permanently, as it connects/disconnects to the kernel automatically (some bugs still need to be fixed though, so you may need to restart it every now and then).

To run a very simple test tree, try

    $ cd ~/LOFAR/Timba/MeqServer/build/gnu3_debug
    $ glish -l ../../test/solver_test.g
    # and then at the glish prompt:
    - solver_test(0)
    # watch sparks fly, and use the browser to examine the tree
    # (if you don't see a tree, try clicking the refresh button at the top of the
    # tree list).

When things go wrong(TM)

The kernel is run in a process called meqserver. This process will usually exit when you exit your glish session, but for reasons that are not yet entirely clear, it may sometimes stay running in the background. Then, next time 'round, to avoid leaving you with two running meqservers (which may lead to a lot of confused software), glish scripts will refuse to start. Simply do

    $ killall -9 meqserver

To clean things up.

meqsolve.g

The meqsolve.g script solves for two sources in a Haystack simulated data set. To run meqsolve.g, you need to get a test measurement set. You can get one from the WaterHole, e.g. try this path:

lofar10:/usr/local/Timba/WH/ms/Haystack-Sim/2PointSourceNoiseless/0128_vis_ninterp.MS

and copy it some place you won't lose it... Now, set up a few more symlinks:

    $ cd ~/LOFAR/Timba/MeqServer/build/gnu3_debug
    $ ln -s ../../test/*.g .
    $ ln -s src/meqserver .
    $ ln -s path/to/your/copy/of/test/measurement/set test.ms

Now, you may run meqsolve.g. The very first time you run it for a particular MS, you need to supply the -filluvw argument to fill the UVW tables. Subsequent runs over the same MS do not need this flag (it won't break things afterwards, but it's slow and useless to repeat the process.)

    $ glish -l meqsolve.g -filluvw

Everything else is controlled by editing meqsolve.g itself...