jplotter / jiveplot

Python based visualization tool for AIPS++/CASA MeasurementSet data

The jplotter command line tool allows the user to quickly visualize the radio-astronomical data contained in a MeasurementSet (ms).

Python support

Starting from 20 Jul 2023 the master branch has been updated to support Py2 and Py3 based systems simultaneously. This version is tagged v2.0. The previous latest Py2-only master was tagged as v1.1 and last-python2-only-master.

5 second workflow

After downloading and having the dependencies installed (as of 30 Oct 2018 you can run from a singularity or Docker image) type:

$ /path/to/jiveplot/jplotter
+++++++++++++++++++++ Welcome to cli +++++++++++++++++++
$Id: command.py,v 1.16 2015-11-04 13:30:10 jive_cc Exp $
  'exit' exits, 'list' lists, 'help' helps
jcli>

and you're in the command line environment. Then open a MS, select data, select what to plot and go.

This README will not explain any further because there is a colourful PDF cookbook/tutorial/explanation with far more detail.

What can be visualized?

Quantities that can be visualized are, e.g., amplitude-versus-time, phase-versus-frequency, amplitude-versus-uv-distance, weight-versus-time, to name but a few.

Some key features:

• the package focuses on powerful selection syntax
• has built-in help for all commands
• the ability to difference whole sets of plots, e.g. to visualize before-after changes or to compare output of different correlators
• time- or frequency averaging of the data before plotting
• plots can be saved to file (postscript).
• plots/data sets can be organized at will
• the data can be indexed (> indexr) to create a scan list, after which powerful scan-based selection can be used
• plotting can be scripted/play back stored commands from text file
• open/visualize multiple data sets at the same time or the same data set from different 'angles'
• the current selection can be written out as a new reference ms; data is not copied but the newly created ms references rows of data in the parent ms. It can be treated as a real ms.

Data selection

ms's can contain several GBs of binary data. Therefore, data selection is desirable, preferably in a fairly natural way, even without knowing the exact details of the experiment's data.

The jplotter selection commands take a stab at suiting the needs of a radio astronomer:

# select a time range near the end of the experiment
jcli> time $end-1h to +2m20s

# select IF 0,1,2 with parallel hand polarizations
jcli> fq  0-2/p
# equivalent, but would not work for XX, YY whereas the former would
jcli> fq  0-2/rr,ll

# select sources whose name matches this
jcli> src j(19|30)*

# select all cross baselines, remove those to stations xx and yy, but add xx-ef
jcli> bl cross -(xx|yy)* +xx(ef)

# select 80% of the band, irrespective of how many channels
# the correlator produced
jcli> ch 0.1*last:0.9*last

# after running indexr, extract a bit of data (trimming 1 minute from either
# end) from scans on sources matching 042* and who are longer than three minutes
jcli> scan start+1m to end-1m where length>3m and field ~ '042*'

Dependencies

The package uses the pyrap, python casacore Python binding to access data.

It uses pgplot to visualize (it was faster and easier than matplotlib): Python binding to pgplot (the github version is preferred over this old link: http://www.jive.eu/~verkout/ppgplot-1.4.tar.gz)

The github version became online during the course of 2018 and has a setup.py which has support for Python2 and 3, where the ppgplot-1.4.tar.gz lacks this.

Note: if the original PGPLOT is giving too many headaches, the Giza library can be used as drop-in replacement for ppgplot to link against for its libpgplot.so. My ppgplot fork's setup.py has support for having both FORTRAN PGPLOT and Giza installed and allows for compile-time selection of which actual pgplot backend to use.

Singularity and Docker container images

As of 30 October 2018 Singularity and Docker images are available. In fact, the Singularity image just runs the Docker image. The jiveplot Docker image contains jiveplot and all its dependencies and is built on top of the excellent kernsuite/kern-4 project.

Even though all functionality is in the Docker image, we advise to run/install Singularity (if you have a choice) for the following reasons:

• X11 forwarding works out of the box with Singularity, which is convenient if you wish to actually see the plots on your screen. According to the interwebs X forwarding can be done through Docker as well but it didn't for me (see below)

• Your ${HOME} directory is visible by default inside the Singularity container. This has the nice effect that your jiveplot command history and aliases are persisted between runs of the image (~/.jcli.history for the history). This in turn means that ^r (reverse-search-history) is actually useful

• I'm not even going to mention the security issues of Docker which has to run as root

Running the Singularity image

UPDATE November 2019 - because of Singularity security changes it is now recommended to use the following method of running the jiveplot container:

$ singularity pull shub://haavee/jiveplot:latest
# this will give you a local `path/to/*.simg` file
$ singularity run --bind <local dir>:<container dir> path/to/*.simg

where <local dir> is the/a directory on your host where your CASA MeasurementSet(s) live and <container dir> is the desired mount point inside the container.

Running the Docker image

Allegedly, running Docker like this:

$ docker run -it --init --network=host -v /tmp/.X11-unix:/tmp/.X11-unix:ro -e DISPLAY="$DISPLAY" -v <local dir>:<container dir> haavee/jiveplot

does X11 forwarding but yours truly has seen it also not work. YMMV.

Both commands should drop you immediately into the jiveplot command line interface:

+++++++++++++++++++++ Welcome to cli +++++++++++++++++++
$Id: command.py,v 1.16 2015-11-04 13:30:10 jive_cc Exp $
  'exit' exits, 'list' lists, 'help' helps
jcli> ms <container dir>/path/to/my_data.ms
MS my_data.ms opened &cet
jcli>