[MITgcm-support] RE: a few MITgcm questions

[Chris Hill]

Ichiro,

 -r8 should not be needed, in fact g77 doesn't support it, so the core code
has to work ok without it. However, it may not have been tested on the Altix
lately. Because of g77, for the kernel code it never matters, but there
could be some stuff in KPP where its assumed (Dimitris any thoughts?).

 For reading files could you for now do

  real*4           KFtheta(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy)
  _RS              KFtmp(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy)
  character*160 KFthetaFnam
  CALL MDSREADFIELD(KFthetaFnam,precFloat32,'RS',Nr,KFtmp, 1, myThid)
  Kftheta = KFtmp

  that should read a 510*6,510 file for your setup that is a straight single
record direct access form with 32-bit reals.
 Depending on
  
 1 - compiler options
 2 - settings of -D_BYTESWAPIO 

 the input will need to be either little-endian or big-endian

 The build options that Dimitri has for the Altix and the Origin both are
set for big-endian (that's the native format on MIPS but not on Itanium). 

It would probably be good to have a 'R4' and 'R8' MDS arg but I have to head
off to Ames soon so I won't have time - I'll be in touch Monday.

Chris


  

  

> -----Original Message-----
> From: Ichiro Fukumori [mailto:fukumori at jpl.nasa.gov] 
> Sent: Saturday, April 03, 2004 6:58 PM
> To: cnh at MIT.EDU
> Cc: bnc at pacific.jpl.nasa.gov; Dimitris Menemenlis; chenze at nas.nasa.gov
> Subject: a few MITgcm questions
> 
> Hi Chris,
> 
> Is compile option -r8 necessary?  It appears to interfere 
> with using sgemv (a single precision BLAS matrix times vector 
> subroutine).
> 
> I have a 3D array on the cubed sphere grid that I need to read in.
> Could you tell me the format I should write it to and the 
> subroutine call to read it.  Presently I have,
>   real*4           KFtheta(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy)
>   character*160 KFthetaFnam
>   CALL MDSREADFIELD(KFthetaFnam,precFloat32,'RS',Nr,KFtheta, 
> 1, myThid) Does MDSREADFIELD work with real*4 array (as 
> opposed to _RS)?
> 
> Thanks,
> Ichiro
> 
> 
> ===============================================================
> Ichiro Fukumori               | Jet Propulsion Laboratory
> e-mail: fukumori at jpl.nasa.gov | Mail Stop 300-323
> phone: +1 (818) 354-6965      | 4800 Oak Grove Drive
> fax: +1 (818) 393-6720        | Pasadena, California 91109, U.S.A.
> ===============================================================
>