This module contains functions to define a new horizontal Grid
and to get information from an existing Grid.
A Grid object is necessary to define a variable.
The following different Grid types are available:

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\begin{deflist}{{\large\tt GRID\_UNSTRUCTURED \ \ }}
\item[{\large\tt GRID\_GENERIC     }]  Generic user defined grid      
\item[{\large\tt GRID\_LONLAT      }]  Regular longitude/latitude grid
\item[{\large\tt GRID\_GAUSSIAN    }]  Regular Gaussian lon/lat grid
\item[{\large\tt GRID\_SPECTRAL    }]  Spherical harmonic coefficients
\item[{\large\tt GRID\_GME         }]  Icosahedral-hexagonal GME grid    
\item[{\large\tt GRID\_CURVILINEAR }]  Curvilinear grid
\item[{\large\tt GRID\_UNSTRUCTURED}]  Unstructured grid
\item[{\large\tt GRID\_LCC         }]  Lambert conformal conic grid
\item[{\large\tt GRID\_REFERENCE   }]  Grid reference number
\end{deflist}
\end{minipage}
