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g2_addfield.c(3) Library Functions Manual g2_addfield.c(3)

NAME

g2_addfield.c - Pack sections 4 through 7 and add them to a GRIB2 message.

SYNOPSIS

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

Functions


g2int g2_addfield (unsigned char *cgrib, g2int ipdsnum, g2int *ipdstmpl, float *coordlist, g2int numcoord, g2int idrsnum, g2int *idrstmpl, float *fld, g2int ngrdpts, g2int ibmap, g2int *bmap)
Pack sections 4 through 7 and adds them to a GRIB2 message.

Detailed Description

Pack sections 4 through 7 and add them to a GRIB2 message.

Author

Stephen Gilbert

Date

2002-11-05

Definition in file g2_addfield.c.

Function Documentation

g2int g2_addfield (unsigned char * cgrib, g2int ipdsnum, g2int * ipdstmpl, float * coordlist, g2int numcoord, g2int idrsnum, g2int * idrstmpl, float * fld, g2int ngrdpts, g2int ibmap, g2int * bmap)

Pack sections 4 through 7 and adds them to a GRIB2 message. They are:

4.
Product Definition Section
5.
Data Representation Section
6.
Bit-Map Section
7.
Data Section

This routine is used with routines g2_create(), g2_addlocal(), g2_addgrid(), and g2_gribend() to create a complete GRIB2 message. Function g2_create() must be called first to initialize a new GRIB2 message. Function g2_addgrid() must be called after g2_create() and before this routine to add the appropriate grid description to the GRIB2 message. A call to g2_gribend() is required to complete GRIB2 message after all fields have been added.

Program History Log

Date Programmer Comments 2002-11-05 Gilbert Initial 2002-12-23 Gilbert Added complex spherical harmonic packing 2003-08-27 Gilbert Added support for new templates using PNG and JPEG2000 algorithms/templates. 2004-11-29 Gilbert JPEG2000 now can use WMO Template 5.40 PNG can use WMO Template 5.41. Added packing algorithm check. 2005-05-10 Gilbert Imposed minimum size on cpack. 2009-01-14 Vuong Changed structure name template to gtemplate 2023-09-08 Engle Added support for new template, 5.42, using CCSDS compression (libaec).

Parameters

cgrib Char array that contains the GRIB2 message to which sections 4 through 7 should be added. Must be allocated large enough to store the entire GRIB2 message.
ipdsnum Product Definition Template Number (see Code Table 4.0).
ipdstmpl Contains the data values for the Product Definition Template specified by ipdsnum.
coordlist Array containg floating point values intended to document the vertical discretisation associated to model data on hybrid coordinate vertical levels.
numcoord number of values in array coordlist.
idrsnum Data Representation Template Number (see Code Table 5.0).
idrstmpl The data values for the Data Representation Template specified by idrsnum. Note that some values in this template (eg. reference values, number of bits, etc...) may be changed by the data packing algorithms. Use this to specify scaling factors and order of spatial differencing, if desired.
fld Array of data points to pack.
ngrdpts Number of data points in grid. i.e. size of fld and bmap.
ibmap Bitmap indicator (see Code Table 6.0)
  • 0 = bitmap applies and is included in Section 6.
  • 1-253 = Predefined bitmap applies.
  • 254 = Previously defined bitmap applies to this field.
  • 255 = Bit map does not apply to this product.

bmap Integer array containing bitmap to be added (if ibmap = 0).

Returns

  • > 0 Current size of updated GRIB2 message
  • G2_ADD_MSG_INIT GRIB message was not initialized. Need to call routine g2_create() first.
  • G2_ADD_MSG_COMPLETE GRIB message already complete. Cannot add new section.
  • G2_BAD_SEC_COUNTS Sum of Section byte counts doesn't add to total byte count.
  • G2_BAD_SEC Previous Section was not 3 or 7.
  • G2_ADDFIELD_BAD_PDT Could not find requested Product Definition Template.
  • G2_ADDFIELD_BAD_GDS Section 3 (GDS) not previously defined in message.
  • G2_ADDFIELD_BAD_DRT Tried to use unsupported Data Representationi Template.
  • G2_ADDFIELD_BAD_BITMAP Specified use of a previously defined bitmap, but one does not exist in the GRIB message.
  • G2_ADDFIELD_BAD_GDT GDT of one of 5.50 through 5.53 required to pack field using DRT 5.51.
  • G2_ADDFIELD_ERR Error packing data field.

Note

Note that the Sections 4 through 7 can only follow Section 3 or Section 7 in a GRIB2 message.

Author

Stephen Gilbert

Date

2002-11-05

Definition at line 100 of file g2_addfield.c.

References aecpack(), cmplxpack(), gtemplate::ext, gtemplate::extlen, extpdstemplate(), G2_ADD_MSG_COMPLETE, G2_ADD_MSG_INIT, G2_ADDFIELD_BAD_BITMAP, G2_ADDFIELD_BAD_DRT, G2_ADDFIELD_BAD_GDS, G2_ADDFIELD_BAD_GDT, G2_ADDFIELD_BAD_PDT, G2_ADDFIELD_ERR, G2_BAD_SEC, G2_BAD_SEC_COUNTS, g2c_check_msg(), G2C_EMSGCOMPLETE, G2C_ENOTGRIB, gbit(), getdim(), getdrstemplate(), getpdstemplate(), getpoly(), jpcpack(), gtemplate::map, gtemplate::maplen, mkieee(), gtemplate::needext, pngpack(), sbit(), sbits(), simpack(), and specpack().

Author

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