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NRAO Home > CASA > CASA Task Reference Manual |
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0.1.69 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 |
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vis |
| Name of input visibility file (MS)
| |
| allowed: | string |
|
| Default: |
| |
selectdata |
| Data selection parameters
| |
| allowed: | bool | |
| Default: | True |
|
spw |
| Selection based on spectral-window/frequency/channel.
| |
| allowed: | any |
|
| Default: | variant
|
|
field |
| Selection based on field names or field index numbers.
Default is all. | |
| allowed: | any |
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| Default: | variant
|
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antenna |
| Selection based on antenna/baselines. Default is all.
| |
| allowed: | any |
|
| Default: | variant
|
|
uvrange |
| Selection based on uv range. Default: entire range.
Default units: meters. | |
| allowed: | any |
|
| Default: | variant
|
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timerange |
| Selection based on time range. Default is entire range.
| |
| allowed: | any |
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| Default: | variant
|
|
correlation |
| Selection based on correlation. Default is all. | |
| allowed: | any |
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| Default: | variant
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scan |
| Selection based on scan numbers. Default is all. | |
| allowed: | any |
|
| Default: | variant
|
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intent |
| Selection based on observation intent. Default is all.
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| allowed: | any |
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| Default: | variant
|
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feed |
| Selection based on multi-feed numbers: Not yet
implemented
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| allowed: | any |
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| Default: | variant
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array |
| Selection based on (sub)array numbers. Default is all.
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| allowed: | any |
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| Default: | variant
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observation |
| Selection based on observation ID. Default is all.
| |
| allowed: | any |
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| Default: | variant
|
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verbose |
| Controls level of information detail reported. True
reports more than False.
| |
| allowed: | bool |
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| Default: | True |
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listfile |
| Name of disk file to write output. Default is none (output
is written to logger only).
| |
| allowed: | string |
|
| Default: |
|
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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 |
|
overwrite |
| If True, tacitly overwrite listfile if it exists.
| |
| allowed: | bool |
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| Default: | False |
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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.
More information about CASA may be found at the
CASA web page
Copyright © 2016 Associated Universities Inc., Washington, D.C.
This code is available under the terms of the GNU General Public Lincense
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