[daip] AIPS help

[Eric Greisen]

Sayali Avachat wrote:
> Hello, 
> 
> I am a PhD student of Florida Institute of Technology. I work on AIPS 
> for my research work.
> I have a question about the files that are generated (as a byproduct?) 
> when I run any task in AIPS.
> I see many weird named files created on my disk (not in AIPS), their 
> names look like - e.g. NXD00Q001.10A, FQD00Q001.10A, WXD00Q001.10A, etc...
> What are these files exactly? What is the their purpose and do I need to 
> keep them on disk or is it OK to delete them? 
> Recently I was trying to delete the files which I don't need from AIPS 
> and then re-catalog the files leftover files in AIPS. but because of the 
> presence of these weird files on my computer disk I was unable 
> to re-catalog the files, apparently there was some conflict of names.
> 
> What do I do in this case? Can I delete these files altogether? These 
> files take up a lot of space on my disk too, so I am really concerned 
> about it.

These files are absolutely essential - never delete aips files with rm 
or other commands from the command line.  You should always use commands 
inside aips - the simplest verb to delete a data set or image is ZAP.
More global deletions are done with ALLDEST.

The NX file is an index table that allows rapid access into UV data.

The FQ file is the file that tells aips what the actual frequencies of 
your data are.  The WX file is a weather table which is not used much - 
although you can edit data based on wind speed and other criteria.

The verb EXTDEST allows you to delete these extension files.

Normally a UV data set is very much bigger than the extension files and 
they really do not matter.  An EVLA SY table may be an exception, but 
that is very useful in calibration and so should not be deleted until it 
has been used.

A terabyte or two of disk now costs around $100 - you should not be 
worrying about disk space.

Eric Greisen