window selection not working as expected

[JamieStevens]

From the file 2009-04-06_1121.RFI, I ATLOD it

atlod in=2009-04-06_1121.RFI out=set1.uv options=noif,unflag

I then unflag all the visibilities otherwise all data is flagged:

uvflag vis=set1.uv flagval=unflag

Now when I go to uvspec or uvplt and select window 1, I get the first IF as expected. When I don't specify a window in select, I get only the first IF. But when I select window 2 I get the error:

### Fatal Error: Invalid window selection, in UVREAD(select)

uvindex shows that both IF windows are present, and indeed a uvsplit creates all the files that one would expect for both IFs, and when one plots the second IF from the split files it appears as normal.

I am calling this priority minor because I've never experienced a problem with selecting the second IF with window before, so it may just be a fluke set of circumstances leading to this bug.

[VincentMcIntyre]

workaround: avoid the NOIF option, or split the IFs into distinct files.

[VincentMcIntyre]

We will always have full Stokes with CABB so NOIF is not needed for such data?

One test case: spacecraft tracking - C999 Sep 2009

[MarkWieringa]

Window selection is only meant to work for multiple windows in a spectrum. When NOIF is used, the data is stored with a uv variable in the data separating the frequencies, there will be only one window at a time in that case. The confusion arises because uvindex will show the frequency setups it finds in a similar way.