Instructions

The beta version of asap2 is available on the ATNF network on linux machines Use e.g. "hydra" or "draco"

To run this version type asap2 to start it (asap is still available for comparison)

File all defects under ​http://sourcecode.atnf.csiro.au/cgi-bin/trac_asap.cgi/newticket and log against Milestone ASAP2 release. Please make sure that you fill in your email address, so you can be kept up-to-date on the defect.

The user guide is attached to this wiki page and should also be scrutinised.

I suggest you take some data you have already used in ASAP (version 1) and re-process it again. ASAP should work with (single pointing) spectral line data from Parkes, Mopra and Tidbinbilla. It supports on/off or frequency switched quotients. There are a few changes in the ASAP2 interface

Changes in ASAP2

Selection of data

Data selection in ASAP2 is far more flexible, i.e. data can be selected on more than just BEAM, IF and POL, e.g Tsys Data can also be selected in slices, e.g. two polarisations for one IF. A selection object has been introduced:

ASAP> myscan = scantable("somethingwith2polsand2ifs.rpf")
ASAP> sel = selector()
ASAP> sel.set_polarisations("XX YY")
ASAP> sel.set_ifs(1)
ASAP> myscan.set_selection(sel)
ASAP> myscan.summary()
ASAP> myscan.set_selection()
ASAP> myscan.summary()

This selection is praticularly important for fitting as the fitter can only process one spectrum at a time. ASAP1 didn't allow slices so that wasn't a problem. Now you have to be careful that you have the correct selection. Use scanatble.nrow() to see how many spectra are in your selection. If there are more than one, the fitter uses the first one. The same selection object can be used to restrict plotting plotter.set_selection(). To unset the selection use set_selection without arguments.

plotting

ASAP2 doesn't support plotting of multiple scantables on the same plot. There is a way around this though:

a = scantable("a.rpf")
b = scantable("b.rpf")
... some processing
sel = selector()
sel.set_scans(0)
sel.set_ifs(1)
# grab the first scan and IF 1 out of both scantables
a.set_selection(sel)
b.set_selection(sel)
both = merge(a,b)
plotter.set_mode("i","s")
plotter.plot(both)

Quotient spectra

scantable.quotient() is not available anymore. ASAP2 does "closest in time" using auto_quotient. This should suit almost all observations. If not let me know.

flagging

ASAP1 only support flagging of whole spectra. ASAP2 allows channel based flagging

# flag channels 100 to 200 in IF 1, leave IF0 untouched
mask = myscan.create_mask([100,200])
sel.set_ifs(1)
myscan.set_selection(sel)
myscan.flag_spectrum(mask)
# reste the selection
myscan.set_selection()

New functions

• scantable.convert_pol() - convert (manipulate) the data between 'linear', 'circular' and 'stokes'
• scantable.set_dirframe() - convert to a new Direction reference frame e.g. 'GALACTIC', 'B1950'

Command Summary

ASAP1	ASAP2
scantable.set_cursor	scantable.set_selection
scantable.get_cursor	scantable.get_selection
plotter.set_cursor	plotter.set_selection

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