mirfiller.summary

return and/or print a summary of the contents of the Miriad dataset

Synopsis
summary(header, verbose, preview)

Description
This function provides a summary of the contents of the Miriad dataset. By default, this information is printed as logger messages (unless the verbose parameter is false). Normally, this will cause the dataset to be scanned in its entirety, if it hasn't been already, to extract the information; by setting preview=F, the scanning will be prevented, and thus the summary may be based only on the first timestep in the dataset. Note that if the mirfiller tool was constructed with preview=T (the default) the dataset will be scanned then; thus, the preview parameter subsequently passed to summary() function will be ignored (since all the needed information has been gathered).

Some of the information can also be returned as a record via the header parameter. Fields that will be loaded into this record include:

nwide -- the maximum number of wide-band channels
nspect -- the maximum number of spectral line windows
nchan -- the maximum (total) number of channels
narray -- the number of array configurations found
npol -- the number of polarizations found
pols -- an array of the polarizations found
starttime -- the UTC starting time in seconds
endtime -- the UTC ending time in seconds
nrec -- the total number of visibility records found
cormode -- the correlator mode of the first correlator setup
telescope -- the names of all the telescopes encountered in the dataset.

Arguments

header	a record to hold the summary information
	Default:	[=] (allowing the caller to ignore the returned information)
verbose	If true, detailed information regarding contents will be sent to the logger.
	Default:	T
preview	if true, the entire file will be read (if it wasn't already scanned when the tool was constructed) to extract information. Set this to false to defeat this behavior (e.g. for very large files). In this case, only the first record of the file will be read; thus, some information may be inaccurate if the dataset is a concatonation of several original datasets.
	Default:	T

Example

frommir := mirfiller('3c273', preview=F, quiet=T);  # preview=F prevents full scanning
hdr := [=];
frommir.summary(hdr, preview=T)   # preview=T causes scanning to happen now

This causes a summary to be sent to the logger which will look something like this:

Miriad UV dataset: 3c273
 Max. no. of visibility records:    990
 Max. no. of spectral line windows: 12 (Max no. of channels: 1280)
 Max. no. of wide-band channels:    14
 No. of array configurations:       1
 No. of polarizations:              1
 Time Range: 1997/11/02/19:44:55 - 1997/11/02/20:03:35
Sources:
     3C273      12:29:06.70     +02.03.08.60 (1 field)
Frequency Setup:
   Mode 6, 1280 line channels, 14 wide channels
 Window  #chans   start freq.     increment    bandwidth    rest freq.
    1      256   93.17534 GHz     -48.83 kHz   12.50 MHz    93.17378 GHz
    2       32   93.11704 GHz   -3125.00 kHz  100.00 MHz    96.41298 GHz
    3       32   93.01704 GHz   -3125.00 kHz  100.00 MHz    96.41298 GHz
    4      256   92.87483 GHz     -48.83 kHz   12.50 MHz    96.41298 GHz
    5       32   92.81705 GHz   -3125.00 kHz  100.00 MHz    96.41298 GHz
    6       32   92.71705 GHz   -3125.00 kHz  100.00 MHz    96.41298 GHz
    7      256   96.10183 GHz      48.83 kHz   12.50 MHz    96.41298 GHz
    8       32   96.16013 GHz    3125.00 kHz  100.00 MHz    96.41298 GHz 
    9       32   96.26013 GHz    3125.00 kHz  100.00 MHz    96.41298 GHz
   10      256   96.40233 GHz      48.83 kHz   12.50 MHz    96.41298 GHz
   11       32   96.46011 GHz    3125.00 kHz  100.00 MHz    96.41298 GHz
   12       32   96.56011 GHz    3125.00 kHz  100.00 MHz    96.41298 GHz
Input looks like a raw BIMA dataset; setting default defpass="rawbima"

Furthermore, the hdr record now holds some information:

- print hdr
[nwide=14, nspect=12, nchan=1280, cormode=6, npol=1, pols=YY, starttime=4.38522e+09, 
telescope=BIMA, scanned=T, endtime=4.38522e+09, narray=1, nrec=990]

Next: mirfiller.getoptions - Function Up: mirfiller - Tool Previous: mirfiller.select - Function Contents Index

	Package	bima
	Module	mirfiller
	Tool	mirfiller

mirfiller.summary - Function