UV Selection - SelInput and SelApply

     subroutine SelInput(key,sels,maxsels)
     logical function SelProbe(sels,object,value)
     subroutine SelApply(tno,sels,flag)

These routines are the usual programmer interface to the uv selection routines. They perform the parsing and checking of the user input, and the calling of the uvselect routine to actually implement the selection process. For more information see uv selection in the Users Manual, and the uvselect routine in this Programmers Manual.

SelInput calls the keya routine to get the user-specified selection criteria. This criteria is then broken into an intermediate form. The argument key is the keyword to be used. Generally it should be 'select'. The real array sels (of size maxsels elements) is used to hold the intermediate form of the selection.

SelApply takes a selection criteria, in its intermediate form, and calls the uvselect routine to apply it. The argument flag determines whether criteria is actually to be used for selection (flag=.true.), or rejection (flag=.false.).

Table 2.6: Arguments to SelProbe

Object	Units
time	Julian day.
antennae	Baseline number = 256*ant1 + ant2.
	One of ant1 or ant2 can be zero.
uvrange	Wavelengths.
uvnrange	Nanoseconds.
visibility	Visibility number (1 relative).
dra	Radians.
ddec	Radians.
pointing	Arcseconds.
amplitude	Same as correlation data.
window	Window Number.

SelProbe returns information about whether uv data with a particular parameter value may have been selected. It does not guarantee that such data might exist in any particular data file. It also has the limitation that information is not present to convert ``uvrange'' and ``uvnrange'' calls into each other. These should be treated with caution. The sels array is the intermediate form returned by SelInput, and value is a double precision value, giving the parameter value that is of interest. The object argument determines the meaning (and the units) of this value. Possible values are given in Table 2.6.

Note that this does not support all objects to uvselect. The name must be given in full (no abbreviations and case is significant).