g2_unpack3.c File Reference

Unpack Section 3 (Grid Definition Section) from a GRIB2 message. More...

#include <stdio.h>
#include <stdlib.h>
#include "grib2_int.h"

Go to the source code of this file.

Functions
g2int	g2_unpack3 (unsigned char *cgrib, g2int *iofst, g2int **igds, g2int **igdstmpl, g2int *mapgridlen, g2int **ideflist, g2int *idefnum)
	This routine unpacks Section 3 (Grid Definition Section) from a GRIB2 message. More...

Detailed Description

Unpack Section 3 (Grid Definition Section) from a GRIB2 message.

Author

Stephen Gilbert

Date

2002-10-31

Definition in file g2_unpack3.c.

Function Documentation

g2_unpack3()

g2int g2_unpack3	(	unsigned char *	cgrib,
		g2int *	iofst,
		g2int **	igds,
		g2int **	igdstmpl,
		g2int *	mapgridlen,
		g2int **	ideflist,
		g2int *	idefnum
	)

This routine unpacks Section 3 (Grid Definition Section) from a GRIB2 message.

Program History Log

Date	Programmer	Comments
2002-10-31	Gilbert	Initial
2009-01-14	Vuong	Changed structure name template to gtemplate

Parameters

cgrib	Char array ontaining Section 3 of the GRIB2 message.
iofst	Pointer to g2int which contains the bit offset for the beginning of Section 3 in cgrib.
igds	Pointer to a pointer which will get a pointer to memory allocated for the GDS array, of length 5. The array will contain information read from the appropriate GRIB Grid Definition Section 3 for the field being returned. igds[0] Source of grid definition (see Table 3.0). igds[1] Number of grid points in the defined grid. igds[2] Number of octets needed for each additional grid points definition. Used to define number of points in each row (or column) for non-regular grids. = 0, if using regular grid. igds[3] Interpretation of list for optional points definition. (See Table 3.11) igds[4] Grid Definition Template Number (see Table 3.1).
igdstmpl	Pointer a pointer to g2int, which will get a pointer to an allocated array that contians containing the data values from the Grid Definition Template specified by igds[4].
mapgridlen	A pointer tat gets the number of elements in igdstmpl. i.e. number of entries in Grid Defintion Template specified by igds[4].
ideflist	(Used if igds[2] .ne. 0) Pointer to integer array containing the number of grid points contained in each row (or column).
idefnum	(Used if igds[2] != 0.) A pointer that gets the number of entries in array ideflist - i.e. number of rows (or columns) for which optional grid points are defined.

Returns

• G2_NO_ERROR No error.
• G2_UNPACK_BAD_SEC Array passed had incorrect section number.
• G2_UNPACK3_BAD_GDT message contains an undefined Grid Definition Template.
• G2_UNPACK_NO_MEM Memory allocation error.

Author

Stephen Gilbert

Date

2002-10-31

Definition at line 62 of file g2_unpack3.c.

References gtemplate::ext, extgridtemplate(), gtemplate::extlen, G2_NO_ERROR, G2_UNPACK3_BAD_GDT, G2_UNPACK_BAD_SEC, G2_UNPACK_NO_MEM, gbit(), gbits(), getgridtemplate(), gtemplate::map, gtemplate::maplen, and gtemplate::needext.

Referenced by g2_getfld(), getdim(), and getpoly().