[MITgcm-devel] problem with exf_getffieldrec and obcs

[Martin Losch]

Hi all,

exf_getffieldrec divides by fldperiod. That means, if it is called  
with fldperiod=0, it produces nonsense for count1/count2. Originally  
it's not called with fldperiod=0, because in that case exf_set_gen is  
never called, but only exf_init_gen, where this case is handled.

However, now this function is also used in obcs_prescribe_exf_yz/xz  
(obcs_prescribe_read.F) where it is possible to have fldperiod=0. I  
have fixed this by including this code:
>      if ( obcsperiod .eq. -12 ) then
> c     obcsperiod=-12 means input file contains 12 monthly means
> c     record numbers are assumed 1 to 12 corresponding to
> c     Jan. through Dec.
>        call cal_GetMonthsRec(
>      O                        fac, first, changed,
>      O                        count0, count1,
>      I                        mycurrenttime, mycurrentiter, mythid
>      &           )

>       elseif ( obcsperiod .eq. 0. _d 0 ) then
> c     this is clearly a hack: we set the values of fac, first,  
> changed,
> c     etc. to read only the first record and only if  
> mycurrentiter=niter0
>        fac = 1. _d 0
>        first = ((mycurrenttime - modelstart) .lt. 0.5*modelstep)
>        changed = .false.
>        count0 = 1
>        count1 = count0
>       elseif ( obcsperiod .lt. 0 ) then
>        print *, 'obcsperiod is out of range'
>        STOP 'ABNORMAL END: S/R OBCS_PRESCIBE_EXF_XZ'
>       else
> c     get record numbers and interpolation factor
>        call exf_GetFFieldRec(
>      I                       obcsstartdate, obcsperiod,
>      I                       useYearlyFields,
>      O                       fac, first, changed,
>      O                       count0, count1, year0, year1,
>      I                       mycurrenttime, mycurrentiter, mythid
>      &                      )
>       endif
>
which works for me, but I wonder if there is a better, and more  
elegant way of doing this, maybe within exf_getffieldrec (otherwise I  
am going to check in this hack, because I need this feature).

Martin