[daip] MSORT problem in 31DEC16 AIPS

[James M. Anderson]

Hello,

I am having a problem with MSORT.  In one UV dataset that I am trying
to sort, MSORT does not properly sort one visibility record.  Instead,
the whole record (time, integration time, baseline, ..., visibility
data) is filled with zeros.  I have come across this problem because
after runnign MSORT I run INDXR, and INDXR complains that the dataset
MSORT produced is not sorted.

This is the first time that that has happened in my batch processing
system.  It does not happen with other datasets, but this one
consistently causes a failure.

The dataset has a 64 MB FITS file (20 MB compressed).  That is
probably too big to send to you by e-mail.

The input dataset has 14241 visibilities, and in the new, sorted
dataset, the *last* visibility of the input dataset is missing (no
corresponding time and baseline in the new dataset), but there is one
visibility record at the location in the new dataset where the
corresponding visibility record should be, looking at the times and
baselines of the surrounding records, but the record is filled with
zero bits.

That happens when I run MSORT with a different output dataset from the
input dataset.  When I run MSORT with the output dataset set to the
input dataset, INDXR does not complain at all, and I find no records
with a zero for the timestamp.

The MSORT and INDXR output is provided below.  Interestingly, the
record of zero bits appears in visibility record 13593, the initial
visibility recortd that needs to be sorted in the last brute-force
pass where there are only 2 records to be sorted.




MSORT1: Task MSORT  (release of 31DEC16) begins
MSORT1: Create S_0748+126  .UVDATA.   1 (UV)  on disk  1  cno   43
MSORT1: Copied SU file from vol/cno/vers  1   45   1 to  1   43   1
MSORT1: Copied FQ file from vol/cno/vers  1   45   1 to  1   43   1
MSORT1: Copied AN file from vol/cno/vers  1   45   1 to  1   43   1
MSORT1: Copied AN file from vol/cno/vers  1   45   2 to  1   43   2
MSORT1: Copied AN file from vol/cno/vers  1   45   3 to  1   43   3
MSORT1: Copied AN file from vol/cno/vers  1   45   4 to  1   43   4
MSORT1: Copied AN file from vol/cno/vers  1   45   5 to  1   43   5
MSORT1: Read UV data for the sort keys
MSORT1: Keys read - sort them
MSORT1: Keys sorted, order established, now resort
MSORT1: Keys now ready to use
MSORT1:      14241 unsorted starting at         1 avg sep     2391
MSORT1: IMSORT: Begin first (neighbor) sort pass
MSORT1:       6451 unsorted starting at         1 avg sep     1942
MSORT1: IMSORT: Begin second (brute-force) sort pass
MSORT1:       3425 unsorted starting at      5292 avg sep      677
MSORT1:       2864 unsorted starting at      8456 avg sep      402
MSORT1:        200 unsorted starting at     10236 avg sep       33
MSORT1:          2 unsorted starting at     13593 avg sep        0
MSORT1: Appears to have ended successfully
MSORT1: kg122 31DEC16 TST: Cpu=      0.4  Real=      0  IO=       305

INDXR1: Task INDXR  (release of 31DEC16) begins
INDXR1: Creating CL table with version number 1
INDXR1: QUITTING: FILE CONTAINS DATA WHICH IS OUT OF TIME ORDER
INDXR1: UV FILE HEADER SORT ORDER IS INCORRECT
INDXR1: Use UVSRT or MSORT to sort the file into  time order
INDXR1: and try again.
INDXR1: Purports to die of UNNATURAL causes
INDXR1: kg122 31DEC16 TST: Cpu=      0.0  Real=      0  IO=        33





Have a good holiday!


James M Anderson


-- 
James M Anderson, PhD
Department 1: Geodesy
Section 1.1:  Space Geodetic Techniques
Tel.:         +49 (0)331/288-28948
Fax:          +49 (0)331/288-1111
E-Mail:       anderson at gfz-potsdam.de
___________________________________

Helmholtz-Zentrum Potsdam
Deutsches GeoForschungsZentrum GFZ
Stiftung des öff. Rechts Land Brandenburg
Telegrafenberg A6
14473 Potsdam
Germany