%
%  Rotate the grid by -37 degrees longitude
%

rlon = -37.0;

gvars = { 'XC','YC','DXF','DYF','RA','XG','YG','DXV', ...
          'DYU','RAZ','DXC','DYC','RAW','RAS','DXG','DYG' };

i = 1;
for i = [ 1:5 ]
  
  fbname = sprintf('llc_p90_%d',i);
  eval([ '!cp ' fbname '.nc ' fbname '_rot.nc' ]);
  
  nc = netcdf([ fbname '_rot.nc' ],'write');
  nxp1 = length( nc('Xp1') );  nx = nxp1 - 1;
  nyp1 = length( nc('Yp1') );  ny = nyp1 - 1;
  XCo = [];
  XGo = [];
  XCo = nc{'XC'}(:);
  XGo = nc{'XG'}(:);
  XC = XCo + rlon;
  XG = XGo + rlon;
  icp = find( XC(:) < -180.0 );  XC(icp) = XC(icp) + 360.0;
  icm = find( XC(:) >  180.0 );  XC(icm) = XC(icm) - 360.0;
  igp = find( XG(:) < -180.0 );  XG(icp) = XG(icp) + 360.0;
  igm = find( XG(:) >  180.0 );  XG(icm) = XG(icm) - 360.0;
  nc{'XC'}(:) = XC(:);
  nc{'XG'}(:) = XG(:);

  gid = fopen([ fbname '.mitgrid' ], 'r', 'ieee-be');
  tmp = reshape(fread(gid,inf,'real*8',0,'ieee-be'),[nxp1*nyp1,16]);
  XC = tmp(:,1) + rlon;
  XG = tmp(:,6) + rlon;
  icp = find( XC(:) < -180.0 );  XC(icp) = XC(icp) + 360.0;
  icm = find( XC(:) >  180.0 );  XC(icm) = XC(icm) - 360.0;
  igp = find( XG(:) < -180.0 );  XG(icp) = XG(icp) + 360.0;
  igm = find( XG(:) >  180.0 );  XG(icm) = XG(icm) - 360.0;
  tmp(:,1) = XC;
  tmp(:,6) = XG;
  fclose( gid );

  gid = fopen([ fbname '_rot.mitgrid' ], 'w', 'ieee-be');
  fwrite(gid,tmp,'real*8');
  fclose( gid );
  
end