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0.1.61 listobs

Requires:

Synopsis
List the summary of a data set in the logger or in a file

Description

List the summary information of a data set in the logger or in a file, based on a data selection. Only rows can be selected and printed. No in-row selection is possible (channel or correlation).

Lists the following properties of a measurement set: scan list, field list, spectral window list with correlators, antenna locations, ms table information.

Arguments





Inputs

vis

Name of input visibility file (MS)

allowed:

string

Default:

selectdata

Data selection parameters

allowed:

bool

Default:

True

spw

spectral-window/frequency/channel

allowed:

any

Default:

variant

field

Field names or field index numbers: ”==>all, field=’0~2,3C286’

allowed:

any

Default:

variant

antenna

antenna/baselines: ”==>all, antenna =’3,VA04’

allowed:

any

Default:

variant

uvrange

uv range: ”==>all; uvrange =’0~100klambda’, default units=meters

allowed:

any

Default:

variant

timerange

time range: ”==>all,timerange=’09:14:0~09:54:0’

allowed:

any

Default:

variant

correlation

Select data based on correlation

allowed:

any

Default:

variant

scan

scan numbers: ”==>all

allowed:

any

Default:

variant

intent

Select data based on observation intent: ”==>all

allowed:

any

Default:

variant

feed

multi-feed numbers: Not yet implemented

allowed:

any

Default:

variant

array

(sub)array numbers: ”==>all

allowed:

any

Default:

variant

observation

Select data based on observation ID: ”==>all

allowed:

any

Default:

variant

verbose

allowed:

bool

Default:

True

listfile

Name of disk file to write output: ”==>to terminal

allowed:

string

Default:

listunfl

List unflagged row counts? If true, it can have significant negative performance impact.

allowed:

bool

Default:

False

cachesize

EXPERIMENTAL. Maximum size in megabytes of cache in which data structures can be held.

allowed:

double

Default:

50

Returns
void

Example

 
 
       List the summary information of a data set in the logger or in a file, based on  
       a data selection. Only rows can be selected and printed. No in-row selection is  
       possible (channel or correlation). Refer to the task listvis to list visibilites.  
 
       Lists the following properties of a measurement set:  
       scan list, field list, spectral window list with  
       correlators, antenna locations, ms table information.  
 
       Keyword arguments:  
       vis -- Name of input visibility file  
               default: none. example: vis=’ngc5921.ms’  
 
       selectdata -- Select a subset of data for flagging  
                    default: False  
                    options: True,False  
                    The summary listing will only apply to the specified selection.  
 
              antenna -- Select data based on baseline  
                    default: ’’ (all); example: antenna=’5&6’ baseline 5-6  
                    antenna=’5&6;7&8’ #baseline 5-6 and 7-8  
                    antenna=’5’ # all cross-correlation baselines between antenna 5 and all other available  
                                  antennas  
                    antenna=’5,6’ # all baselines with antennas 5 and 6  
                    antenna=’1&&1’ # only the auto-correlation baselines for antenna 1  
                    antenna=’1&&*’ # cross and auto-correlation baselines between antenna 1  
                                             and all other available antennas  
                    antenna=’1~7&&&’ # only the auto-correlation baselines for antennas in range 1~7  
              spw -- Select data based on spectral window and channels  
                    default: ’’ (all); example: spw=’1’  
                    spw=’<2’ #spectral windows less than 2  
                    spw=’>1’ #spectral windows greater than 1  
              correlation -- Correlation types  
                    default: ’’ (all);  
                    example: correlation=’RR LL’  
              field -- Select data based on field id(s) or name(s)  
                    default: ’’ (all); example: field=’1’  
                    field=’0~2’ # field ids inclusive from 0 to 2  
                    field=’3C*’ # all field names starting with 3C  
              uvrange -- Select data within uvrange (default units meters)  
                    default: ’’ (all); example:  
                    uvrange=’0~1000klambda’; uvrange from 0-1000 kilo-lamgda  
                    uvrange=’>4klamda’;uvranges greater than 4 kilo-lambda  
                    uvrange=’0~1000km’; uvrange in kilometers  
              timerange  -- Select data based on time range:  
                    default = ’’ (all); example,  
                    timerange = ’YYYY/MM/DD/hh:mm:ss~YYYY/MM/DD/hh:mm:ss’  
                    Note: YYYY/MM/DD can be dropped as needed:  
                    timerange=’09:14:0~09:54:0’ # this time range  
                    timerange=’09:44:00’ # data within one integration of time  
                    timerange=’>10:24:00’ # data after this time  
                    timerange=’09:44:00+00:13:00’ #data 13 minutes after time  
              scan -- Select data based on scan number  
                    default: ’’ (all); example: scan=’>3’  
              intent -- Select data based on observation intent  
                    default: ’’ (all); example: intent=’*CAL*,*BAND*’  
              feed -- Selection based on the feed - NOT IMPLEMENTED YET  
              array -- Selection based on the antenna array  
              observation -- Selection based on the observation ID  
                    default: ’’ (all); example: observation=’1’ or observation=1  
 
 
       verbose -- level of detail  
             verbose=True: (default); scan and antenna lists  
             verbose=False: less information  
 
       listfile -- name of disk file to write output.  
               default: None. Example: listfile=’list.txt’  
 
       listunfl -- List unflagged row counts? If true, it can have significant negative performance impact.  
 
       cachesize -- maximum size of the memory cache in megabytes in which data structures can be  
                    stored. For very large datasets this can be increased for possibly better performance.  
                    THIS IS ONLY EXPERIEMENTAL FOR NOW, AND INCREASING THE VALUE OF THIS PARAMETER DOES NOT GUARANTEE INCREASED  
                    SPEED. DEPENDING ON ITS (LACK OF) USEFULNESS, IT MAY BE REMOVED IN THE FUTURE.  
 
 
      The ’Int (s)’ column is the average of the MS’s INTERVAL column  
      for each scan, so in a time-averaged MS ’Int’ = 9.83s more likely  
      means 5 10s integrations and 1 9s integration (timebin) than 6  
      9.83s integrations.  
 
    DESCRIPTION OF ALGORITHM TO CALCULATE THE NUMBER OF UNFLAGGED ROWS  
    The number of unflagged rows are only computed if listunfl=True. Computing these quantity  
    can have a negative performance impact, especially for large datasets.  
    The number of unflagged rows (the nUnflRows columns in the scans and fields portions of the listing) is  
    calculated by summing the fractional unflagged bandwidth for each row (and hence why the number of unflagged  
    rows, in general, is not an integer). Thus a row which has half of its  
    total bandwidth flagged contributes 0.5 rows to the unflagged row count. A row with 20 of 32 channels of  
    homogeneous width contributes 20/32 = 0.625 rows to the unflagged row count. A row with a value of False  
    in the FLAG_ROW column is not counted in the number of unflagged rows.  


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