Setting/Getting Rest Frequencies

NRAO Home > CASA > CASA Cookbook and User Reference Manual

8.3.10 Setting/Getting Rest Frequencies

The rest frequencies used in the data can be retrieved by sd.scantable.get_restfreqs() and set to new values by sd.scantable.set_restfreqs(). The CASA version of ASAP now can store multiple rest frequencies for each IF.

scans.get_restfreqs() #retrieve current rest frequencies
#{0: [45490258000.0]

All of the rest frequencies currently set to the data are listed in python dictionary for each MOLECULE_ID.

Here is an example of setting multiple rest frequencies for spectra of a particular IF:

  #Select IFs, then set rest frequencies,
  sel=sd.selector()
  sel.setifs(0)
  scans.set_selection(sel)
  scans.set_restfreqs([45490258000.0,45590258000.0,45690258000.0])

NOTE: there is no functionality yet to select a specific rest frequency to apply to a specific line, etc. Currently, the first one in the list of the rest frequencies is used for such calculation.

[next] [prev] [prev-tail] [front] [up]

More information about CASA may be found at the CASA web page

This code is available under the terms of the GNU General Public Lincense