[daip] FITLD problem with DiFX output

[Olaf Wucknitz]

Hi Walter,

my AIPS was just a couple of weeks old. I just ran the MNJ to check if 
there are any updates, but WRINI in FITLD.FOR is unchanged.
However, the loop starts at line 17696 in the latest version.

Cheers,
Olaf



> Hi Olaf,
> 
> How old is your AIPS?  A number of bugs of this nature have been found in
> FITLD as a result of difx development.  If it is more than ~6 months old I
> would upgrade your AIPS and try again.
> 
> -W
> 
> On Tue, 31 Mar 2009, Olaf Wucknitz wrote:
> 
> > Dear DAIP (and Walter),
> >
> > when FITLDing data from DiFX (correlated here in Bonn), I stumbled across
> > what may be a bug in FITLD.
> >
> > In subroutine WRINI, it converts the weather table from WR to WX format.
> > With data from the VLBA correlator, both seem to have the same number of
> > columns. In the output from difx2fits, there are two additional columns
> > (WIND_GUST and PRECIPITATION).
> > WRINI loops through all columns it is interested in and tries to locate
> > them in the WR table. Unfortunately this loop seems to use the wrong
> > number of columns (which does not matter if they are equal). This concerns
> > the following lines of code (FITLD.FOR starting at line 17678):
> >
> >      DO 150 I = 1,NCOL
> >         IPOINT = WRKOLS(I)
> >         IF (IPOINT.EQ.0) IPOINT = WRKOL2(I)
> >         IF (IPOINT.GT.0) THEN
> >            WRKOLS(I) = DATP(IPOINT,1)
> >            WRNUMV(I) = DATP(IPOINT,2) / 10
> >         ELSE
> >            WRKOLS(I) = -1
> >            WRNUMV(I) = 0
> >            END IF
> > 150     CONTINUE
> >
> >
> > Here NCOL is the number of columns in WR. The loop should really only go
> > to MAXWRC which is the number of elements in WRKOLS and WRKOL2. A
> > modified version works fine for me.
> >
> > In the distributed binary version (Linux) this did not cause any problems
> > but it produced a segmentation fault in my own version. Hunting this down
> > was a bit tedious, because each FITLD run (150GB) took 3 hours, and
> > smaller files ran through without errors.
> >
> >
> > Cheers,
> > Olaf