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0.1.140 visstat

Requires:

Synopsis
Displays statistical information from a Measurement Set, or from a Multi-MS

Arguments





Outputs

xstat

Statistical information for the selected measurement set

allowed:

any

Default:

variant

Inputs

vis

Name of Measurement Set or Multi-MS

allowed:

string

Default:

axis

Which values to use

allowed:

string

Default:

amplitude

datacolumn

Which data column to use (data, corrected, model)

allowed:

string

Default:

data

useflags

Take flagging into account?

allowed:

bool

Default:

True

spw

spectral-window/frequency/channel

allowed:

string

Default:

field

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

allowed:

string

Default:

selectdata

More data selection parameters (antenna, timerange etc)

allowed:

bool

Default:

True

antenna

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

allowed:

string

Default:

uvrange

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

allowed:

string

Default:

timerange

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

allowed:

string

Default:

correlation

Select data based on correlation

allowed:

string

Default:

scan

scan numbers: ”==>all

allowed:

string

Default:

array

(sub)array numbers: ”==>all

allowed:

string

Default:

observation

observation ID number(s): ” = all

allowed:

any

Default:

variant

Returns
void

Example

 
 
        This task returns statistical information about data in a Measurement  
        Set or Multi-MS.  
 
        The following values are computed: mean value, sum of values,  
        sum of squared values, median, median absolute deviation, quartile,  
        minimum, maximum, variance, standard deviation, and root mean square.  
 
        The following axes are supported: uvw, flag, weight, sigma, antenna1,  
        antenna2, feed1, feed2, field_id, array_id, data_desc_id, flag_row,  
        interval, scan, scan_number, time, weight_spectrum, amp, amplitude,  
        phase, real, imag, imaginary, and uvrange.  
 
        Optionally, the statistical information can be computed based only  
        on a given subset of the measurement set.  
 
        Note: If the MS consists of inhomogeneous data, for example several  
        spectral windows each having a different number of channels, it may be  
        necessary to use selection parameters to select a homogeneous subset of  
        the MS, e.g. spw=’2’.  
 
        Keyword arguments:  
 
        vis  --- Name of input Measurement Set or Multi-MS  
                  default: ’’, example: vis=’my.ms’  
 
        axis -- Which data to analyze.  
 
                default: ’amplitude’  
                axis=’phase’  
                axis=’imag’  
                axis=’scan_number’  
                axis=’flag’  
 
                The phase of a complex number is in radians in the range [-pi; pi[.  
 
 
        datacolumn -- Which data column to use for complex data.  
                default: ’data’  
                datacolumn=’data’  
                datacolumn=’corrected’  
                datacolumn=’model’  
 
        useflags -- Take MS flags into account?  
                default: True  
                useflag=False  
                useflag=True  
        If useflags=False, flagged values are included in the statistics.  
        If useflags=True, any flagged values are not used in the statistics.  
 
        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  
                spw=’0:0~10’ # first 10 channels from spw 0  
                spw=’0:0~5;56~60’ # multiple separated channel chunks.  
 
        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  
 
        selectdata -- Other data selection parameters  
                default: True  
        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 baselines with antenna 5  
                antenna=’5,6’ # all baselines with antennas 5 and 6  
        correlation -- Correlation types  
                default: ’’ (all);  
                example: correlation=’RR LL’  
        uvrange -- Select data within uvrange (default units meters)  
                default: ’’ (all); example:  
                uvrange=’0~1000klambda’; uvrange from 0-1000 kilo-lambda  
                uvrange=’>4klambda’;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’  
        array -- Selection based on the antenna array  
        observation -- Selection by observation ID(s).  
               default: ’’ (all); example: observation=’1~3’  
 


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