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ms.cvelfreqs - Function

1.3.1 calculate the transformed grid of the SPW obtained by combining a given set of SPWs (MS is not modified)


Description

Take the spectral grid of a given spectral window, tranform and regrid it as prescribed by the given grid parameters (same as in cvel and clean) and return the transformed values as a list. The MS is not modified. Useful for tests of gridding parameters before using them in cvel or clean.

Arguments





Inputs

spwids

The list of ids of the spectral windows from which the input grid is to be taken.

allowed:

intArray

Default:

0

fieldids

The list of ids of the fields which are selected (for observation time determination), default: all

allowed:

intArray

Default:

0

obstime

the observation time to assume, default: time of the first row of the MS =

allowed:

string

Default:

mode

”channel”, ”velocity”, ”frequency”, or ”channel_b”, default =

allowed:

string

Default:

channel

nchan

number of channels, default = all =

allowed:

int

Default:

-1

start

start channel, default =

allowed:

any

Default:

variant 0

width

new channel width, default =

allowed:

any

Default:

variant 1

phasec

phase center, default = first field in selection =

allowed:

any

Default:

variant

restfreq

rest frequency, default =

allowed:

any

Default:

variant 1.4GHz

outframe

LSRK, LSRD, BARY, GALACTO, LGROUP, CMB, GEO, TOPO, or SOURCE default = keep reference frame =

allowed:

string

Default:

veltype

radio or optical, default =

allowed:

string

Default:

radio

verbose

If true, create log output

allowed:

bool

Default:

true

Returns
doubleArray

Example

 
    ms.open(’my.ms’)  
    ms.cvelfreqs(spwids=[1], mode=’channel’, nchan=20, start=2, width=3, outframe=’LSRK’)  
 
    will take the grid of SPW 1 (i.e. the second in the SPW table), regrid it as in cvel  
    with the given grid parameters and return the resulting channel centers as an array.  
    The MS is not modified. See help cvel for more details on the grid parameters.  
 

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