# $Header: /u/gcmpack/MITgcm/utils/matlab/cs_grid/README,v 1.4 2007/02/06 22:07:28 dimitri Exp $
# $Name:  $

Matlab scripts (written by Alistair) specific to Cubed-Shere grid:
 [initially in utils/matlab and moved here Sep. 15, 2005]

Interpolate to Lat-Lon grid:
 cube2latlon.m 
 cube2latlon_fast.m 
 cube2latlon_preprocess.m 
 uvcube2latlon.m
 uvcube2latlon_fast.m 
 uvcube2latlongrid.m  (faster version, from Guillaume Maze)

make graphics of cs-grid fields:
 merccube.m 
 displaytiles.m 
 drawedges.m 
 fancycube.m 
 plotcube.m 

others:
 permutetiles.m 
 tiles.m

--------------------------------------------------------------------------
Some tools specific to the Cubed-Sphere grid :

split_C_cub.m   :: split a 2d,3d global CS-field into 6 faces ;
        apply to cell-centered CS-field ; extend the face array by 
        adding 1 row & 1 column (like the exchanges)
split_Z_cub.m   :: split a 2d,3d global CS-field into 6 faces ;
        apply to cell-corner CS-field ; extend the face array by 
        adding 1 row & 1 column (like the exchanges)
split_UV_cub.m  :: split the 2 C-grid components of a vector 
        (2d,3d global CS-field) into 6 faces ; extend the face array 
        by adding 1 row or 1 column (like the exchanges)

cubeZ2latlon.m  :: interpolate a CS-field to regular Lat-lon grid ;
        similar to cube2latlon.m but apply to a field that is
        located at the corner point of the C-grid cell.
        (deal with the 2 "missing corners")

calc_vort_cs.m  :: compute vorticity (vertical component) on CS-grid
        from MITgcm output velocity fields u,c (on C-grid); 
        Use the model discretization of vorticity. 

the following scripts are reading a file that contains the orientation
        of the local direction of the CS-grid relative to E-W,N-S direction.  
  file= proj_cs[]_2uEvN.bin :: cos & sin of rotation angle, 
                      format:: real*8, big-endian, size=32x6x32 x2(cos+sin)
        for standard cs32 grid, the corresponding file is:
           verification/global_ocean.cs32x15/input/proj_cs32_2uEvN.bin 

rotate_csAg_EN.m :: Rotate cell centered (A-grid) U,V vector components
        of CS-grid to East,North directions. works for 2D or 3D vector.

rotate_csCg_EN.m :: Rotate MITgcm C-grid U,V vector components of CS-grid 
        to East,North directions. done in 2 steps: 1rst compute the average
        at the cell-center and then rotate the vector.

uvLatLon2cube.m :: interpolate a 2 components vector field U,V (on A-grid)
        to the MITgcm CS-grid (C-grid).

More in dir bk_line:
 Scripts that generate "broken-lines" (used to compute Meridional Transport
  stream-function and vertically integrated horizontal stream-function)
 + a README file + an example for each one.

And in dir read_cs:
 Scripts for reading and writing cube-sphere binary output in various ways.
 Look at read_cs/read_cs.txt for example usage.