.TH "g2_unpack3.c" 3 "Tue May 3 2022" "Version 1.6.4" "NCEPLIBS-g2c" \" -*- nroff -*-
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.SH NAME
g2_unpack3.c \- Unpack Section 3 (Grid Definition Section) as defined in GRIB Edition 2\&.  

.SH SYNOPSIS
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.PP
\fC#include <stdio\&.h>\fP
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\fC#include <stdlib\&.h>\fP
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\fC#include 'grib2\&.h'\fP
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.SS "Functions"

.in +1c
.ti -1c
.RI "\fBg2int\fP \fBg2_unpack3\fP (unsigned char *cgrib, \fBg2int\fP *iofst, \fBg2int\fP **igds, \fBg2int\fP **igdstmpl, \fBg2int\fP *mapgridlen, \fBg2int\fP **ideflist, \fBg2int\fP *idefnum)"
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.RI "This routine unpacks Section 3 (Grid Definition Section) as defined in GRIB Edition 2\&. "
.in -1c
.SH "Detailed Description"
.PP 
Unpack Section 3 (Grid Definition Section) as defined in GRIB Edition 2\&. 


.PP
\fBAuthor\fP
.RS 4
Stephen Gilbert 
.RE
.PP
\fBDate\fP
.RS 4
2002-10-31 
.RE
.PP

.PP
Definition in file \fBg2_unpack3\&.c\fP\&.
.SH "Function Documentation"
.PP 
.SS "\fBg2int\fP g2_unpack3 (unsigned char * cgrib, \fBg2int\fP * iofst, \fBg2int\fP ** igds, \fBg2int\fP ** igdstmpl, \fBg2int\fP * mapgridlen, \fBg2int\fP ** ideflist, \fBg2int\fP * idefnum)"

.PP
This routine unpacks Section 3 (Grid Definition Section) as defined in GRIB Edition 2\&. PROGRAM HISTORY LOG:
.IP "\(bu" 2
2002-10-31 Gilbert
.IP "\(bu" 2
2009-01-14 Vuong Changed structure name template to gtemplate
.PP
.PP
\fBParameters\fP
.RS 4
\fIcgrib\fP Char array ontaining Section 3 of the GRIB2 message\&. 
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\fIiofst\fP Bit offset for the beginning of Section 3 in cgrib\&. 
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\fIigds\fP Contains information read from the appropriate GRIB Grid Definition Section 3 for the field being returned\&.
.IP "\(bu" 2
igds[0] Source of grid definition (see Code Table 3\&.0)
.IP "\(bu" 2
igds[1] Number of grid points in the defined grid\&.
.IP "\(bu" 2
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\&.
.IP "\(bu" 2
igds[3] Interpretation of list for optional points definition\&. (Code Table 3\&.11)
.IP "\(bu" 2
igds[4] Grid Definition Template Number (Code Table 3\&.1)\&. 
.PP
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\fIigdstmpl\fP - Pointer to integer array containing the data values for the specified Grid Definition Template (NN=igds[4])\&. Each element of this integer array contains an entry (in the order specified) of Grid Defintion Template 3\&.NN 
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\fImapgridlen-\fP Number of elements in igdstmpl[]\&. i\&.e\&. number of entries in Grid Defintion Template 3\&.NN (NN=igds[4])\&. 
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\fIideflist\fP (Used if igds[2] \&.ne\&. 0) Pointer to integer array containing the number of grid points contained in each row ( or column )\&. (part of Section 3)\&. 
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\fIidefnum\fP (Used if igds[2] \&.ne\&. 0) The number of entries in array ideflist\&. i\&.e\&. number of rows (or columns) for which optional grid points are defined\&.
.RE
.PP
\fBReturns\fP
.RS 4
.IP "\(bu" 2
0 no error
.IP "\(bu" 2
2 Not Section 3
.IP "\(bu" 2
5 'GRIB' message contains an undefined Grid Definition Template\&.
.IP "\(bu" 2
6 memory allocation error
.PP
.RE
.PP
\fBAuthor\fP
.RS 4
Stephen Gilbert 
.RE
.PP
\fBDate\fP
.RS 4
2002-10-31 
.RE
.PP

.PP
Definition at line 53 of file g2_unpack3\&.c\&.
.PP
References gtemplate::ext, extgridtemplate(), gtemplate::extlen, gbit(), gbits(), getgridtemplate(), gtemplate::map, gtemplate::maplen, and gtemplate::needext\&.
.PP
Referenced by g2_getfld(), getdim(), and getpoly()\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for NCEPLIBS-g2c from the source code\&.