[MITgcm-support] RE: conversion from local tile index to global new I/O format index

[Chris Hill]

Yes that is the loop. 
For a 510x510 cube that will return global i {1:510*6} and global j {1:510}.


Chris 

> -----Original Message-----
> From: Ichiro Fukumori [mailto:if at pacific.jpl.nasa.gov] 
> Sent: Tuesday, March 30, 2004 3:33 PM
> To: 'Andrew Eichmann'; Dimitris Menemenlis
> Cc: Chris Hill
> Subject: Re: conversion from local tile index to global new 
> I/O format index
> 
> Hi Andrew,
> 
> Could you give me the exact do loop to get the global i (1 to 
> Nx) and global j (1 to Ny) index at point, (i,j,bi,bj) within 
> a tile?  Is it
> 
> i_global_io_index = exch2_txglobalo(W2_myTileList(bi))+i-1
> j_global_io_index = exch2_tyglobalo(W2_myTileList(bi))+j-1
> 
> Thanks,
> Ichiro
> 
> At 02:14 PM 3/30/2004 -0500, 'Andrew Eichmann' wrote:
> >* Dimitris Menemenlis <menemenlis at jpl.nasa.gov> wrote on 
> Tue, Mar 30, 
> >2004 at 10:01:37AM -0800
> > >
> > > Chris, Andy,
> > >
> > > >          i_global_io_index = 
> exch_tx_globallo(W2_myTileList(bi))+i-1
> > > >          j_global_io_index = 
> > > > exch_ty_globallo(W2_myTileList(bi))+j-1
> > >
> > > is not exactly what we need.  Two problems, the first is that the 
> > > exch_tx_globallo and exch_ty_globallo variables do not exist.  I 
> > > assume you
> >
> >They're exch2_txglobalo and exch2_tyglobalo.  There's a 
> mismatch in the 
> >comments that we should clean up.
> >
> > > mean exch2.  The second problem is that these variables seem to 
> > > point
> > to face
> > > corners, not tile corners.  So some more tile gymnastics must be 
> > > needed
> > to get
> >
> >They should point to the tile corners within the face.  That, plus 
> >exch2_mydnx, exch2_mydny (which I just realised I haven't 
> documented - 
> >these are dimensions of the faces, indexed to the tile), and 
> >exch2_myFace should get you what you need.
> >
> > > P.P.S.  Anybody running the mitgcm using cygwin?
> >
> >Would this be for performance tuning? ;-)
> >
> >-A
> 
> ===============================================================
> 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.
> ===============================================================
>