Pack up Sections 4 through 7 for a given field and adds them to a GRIB2 message. More...

#include <stdio.h>
#include <stdlib.h>
#include "grib2.h"

Functions
void	cmplxpack (g2float , g2int, g2int, g2int , unsigned char , g2int )
	This subroutine packs up a data field using a complex packing algorithm as defined in the GRIB2 documention. More...

g2int	g2_addfield (unsigned char cgrib, g2int ipdsnum, g2int ipdstmpl, g2float coordlist, g2int numcoord, g2int idrsnum, g2int idrstmpl, g2float fld, g2int ngrdpts, g2int ibmap, g2int bmap)
	This routine packs up Sections 4 through 7 for a given field and adds them to a GRIB2 message. More...

g2int	getdim (unsigned char , g2int , g2int , g2int )
	This subroutine returns the dimensions and scanning mode of a grid definition packed in GRIB2 Grid Definition Section 3 format. More...

g2int	getpoly (unsigned char , g2int , g2int , g2int )
	This subroutine returns the J, K, and M pentagonal resolution parameters specified in a GRIB Grid Definition Section (GDS) used spherical harmonic coefficients using GDT 5.50 through 5.53. More...

void	jpcpack (g2float , g2int, g2int, g2int , unsigned char , g2int )
	This subroutine packs up a data field into a JPEG2000 code stream. More...

void	pngpack (g2float , g2int, g2int, g2int , unsigned char , g2int )
	This subroutine packs up a data field into PNG image format. More...

void	simpack (g2float , g2int, g2int , unsigned char , g2int )
	This subroutine packs up a data field using the simple packing algorithm as defined in the GRIB2 documention. More...

void	specpack (g2float , g2int, g2int, g2int, g2int, g2int , unsigned char , g2int )
	This subroutine packs a spectral data field using the complex packing algorithm for spherical harmonic data as defined in the GRIB2 Data Representation Template 5.51. More...

Detailed Description

Pack up Sections 4 through 7 for a given field and adds them to a GRIB2 message.

Author: Stephen Gilbert

Date: 2002-11-05

Definition in file g2_addfield.c.

Function Documentation

◆ cmplxpack()

void cmplxpack	(	g2float *	fld,
		g2int	ndpts,
		g2int	idrsnum,
		g2int *	idrstmpl,
		unsigned char *	cpack,
		g2int *	lcpack
	)

This subroutine packs up a data field using a complex packing algorithm as defined in the GRIB2 documention.

It supports GRIB2 complex packing templates with or without spatial differences (i.e. DRTs 5.2 and 5.3). It also fills in GRIB2 Data Representation Template 5.2 or 5.3 with the appropriate values.

Parameters

fld	Contains the data values to pack.
ndpts	The number of data values in array fld
idrsnum	Data Representation Template number. Must equal 2 or 3.
idrstmpl	Contains the array of values for Data Representation Template 5.2 or 5.3 0 Reference value - ignored on input, set by compack routine. 1 Binary Scale Factor 2 Decimal Scale Factor 6 Missing value management 7 Primary missing value 8 Secondary missing value 16 Order of Spatial Differencing ( 1 or 2 )
cpack	The packed data field.
lcpack	length of packed field cpack.

Author: Stephen Gilbert

Date: 2004-08-27

Definition at line 35 of file cmplxpack.c.

References compack(), and misspack().

Referenced by g2_addfield().

◆ g2_addfield()

g2int g2_addfield	(	unsigned char *	cgrib,
		g2int	ipdsnum,
		g2int *	ipdstmpl,
		g2float *	coordlist,
		g2int	numcoord,
		g2int	idrsnum,
		g2int *	idrstmpl,
		g2float *	fld,
		g2int	ngrdpts,
		g2int	ibmap,
		g2int *	bmap
	)

This routine packs up Sections 4 through 7 for a given field and adds them to a GRIB2 message.

They are Product Definition Section, Data Representation Section, Bit-Map Section and Data Section, respectively.

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

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
-1 GRIB message was not initialized. Need to call routine g2_create() first.
-2 GRIB message already complete. Cannot add new section.
-3 Sum of Section byte counts doesn't add to total byte count.
-4 Previous Section was not 3 or 7.
-5 Could not find requested Product Definition Template.
-6 Section 3 (GDS) not previously defined in message.
-7 Tried to use unsupported Data Representationi Template.
-8 Specified use of a previously defined bitmap, but one does not exist in the GRIB message.
-9 GDT of one of 5.50 through 5.53 required to pack field using DRT 5.51.
-10 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 106 of file g2_addfield.c.

References cmplxpack(), gtemplate::ext, gtemplate::extlen, extpdstemplate(), gbit(), getdim(), getdrstemplate(), getpdstemplate(), getpoly(), jpcpack(), gtemplate::map, gtemplate::maplen, mkieee(), gtemplate::needext, pngpack(), sbit(), sbits(), simpack(), and specpack().

◆ getdim()

g2int getdim	(	unsigned char *	csec3,
		g2int *	width,
		g2int *	height,
		g2int *	iscan
	)

This subroutine returns the dimensions and scanning mode of a grid definition packed in GRIB2 Grid Definition Section 3 format.

Parameters

csec3	Character array that contains the packed GRIB2 GDS.
width	x (or i) dimension of the grid. 0 if grid is not recognized.
height	y (or j) dimension of the grid. 0 if grid is not recognized.
iscan	Scanning mode (see Table 3.4). 0 of grid not recognized.

Returns: Always returns 0.

Author: Stephen Gilbert

Date: 2002-12-11

Definition at line 29 of file getdim.c.

References g2_unpack3().

Referenced by g2_addfield().

◆ getpoly()

g2int getpoly	(	unsigned char *	csec3,
		g2int *	jj,
		g2int *	kk,
		g2int *	mm
	)

This subroutine returns the J, K, and M pentagonal resolution parameters specified in a GRIB Grid Definition Section (GDS) used spherical harmonic coefficients using GDT 5.50 through 5.53.

If 51 - complex data spectral packing is used as the data representation template number (see Table 5.0), then the Grid Definition Template Number in section 3 should be one of:

50: Spherical Harmonic Coefficients (See Template 3.50)
51: Rotated Spherical Harmonic Coefficients (See Template 3.51)
52: Stretched Spherical Harmonic Coefficients (See Template 3.52)
53: Rotated and Stretched Spherical Harmonic Coefficients (See Template 3.53)

Parameters

csec3	Character array that contains the packed GRIB2 GDS.
jj	J pentagonal resolution parameter.
kk	K pentagonal resolution parameter.
mm	M pentagonal resolution parameter.

Returns: always returns 0.

Note: Returns jj, kk, and mm set to zero, if grid template not recognized.

Author: Stephen Gilbert

Date: 2002-12-11

Definition at line 40 of file getpoly.c.

References g2_unpack3().

Referenced by g2_addfield().

◆ jpcpack()

void jpcpack	(	g2float *	fld,
		g2int	width,
		g2int	height,
		g2int *	idrstmpl,
		unsigned char *	cpack,
		g2int *	lcpack
	)

This subroutine packs up a data field into a JPEG2000 code stream.

After the data field is scaled, and the reference value is subtracted out, it is treated as a grayscale image and passed to a JPEG2000 encoder. It also fills in GRIB2 Data Representation Template 5.40 or 5.40000 with the appropriate values.

Program History Log

Date	Programmer	Comments
2003-08-17	Gilbert	Initial.
2004-11-92	Gilbert	Fixed bug packing a near constant field.
2004-07-19	Gilbert	If jpeg2000 encoding fails, try again with different encoder options.
2005-05-10	Gilbert	Imposed minimum size on cpack.

Parameters

fld	Contains the data values to pack.
width	number of points in the x direction.
height	number of points in the y direction.
idrstmpl	Contains the array of values for Data Representation Template Table 5.40 or 5.40000. 0 Reference value - ignored on input, set by jpcpack routine. 1 Binary Scale Factor - used on input, unchanged by jpcpack routine. 2 Decimal Scale Factor - used on input, unchanged by jpcpack routine. 3 number of bits for each data value - ignored on input 4 Original field type - currently ignored on input Data values assumed to be reals. Set to 0 on output. 5 if 0 use lossless compression, if 1 use lossy compression. 6 Desired compression ratio, if idrstmpl[5]=1. Set to 255, if idrstmpl[5]=0.
cpack	The packed data field.
lcpack	Pointer that points to a g2int which contains the length of packed field in cpack. This must be set by the calling function.

Author: Stephen Gilbert

Date: 2003-08-17

Definition at line 53 of file jpcpack.c.

References enc_jpeg2000(), int_power(), mkieee(), and sbits().

Referenced by g2_addfield().

◆ pngpack()

void pngpack	(	g2float *	fld,
		g2int	width,
		g2int	height,
		g2int *	idrstmpl,
		unsigned char *	cpack,
		g2int *	lcpack
	)

This subroutine packs up a data field into PNG image format.

After the data field is scaled, and the reference value is subtracted out, it is treated as a grayscale image and passed to a PNG encoder. It also fills in GRIB2 Data Representation Template 5.41 or 5.40010 with the appropriate values.

Parameters

fld	Contains the data values to pack.
width	number of points in the x direction.
height	number of points in the y direction.
idrstmpl	Contains the array of values for Data Representation Template 5.41 or 5.40010. 0 Reference value - ignored on input, set by pngpack routine. 1 Binary Scale Factor - used on input. 2 Decimal Scale Factor - used on input. 3 number of bits for each grayscale pixel value - ignored on input. 4 Original field type - currently ignored on input, set = 0 on output. Data values assumed to be reals.
cpack	The packed data field.
lcpack	length of packed field cpack.

Author: Stephen Gilbert

Date: 2003-08-27

Definition at line 38 of file pngpack.c.

References enc_png(), int_power(), mkieee(), and sbits().

Referenced by g2_addfield().

◆ simpack()

void simpack	(	g2float *	fld,
		g2int	ndpts,
		g2int *	idrstmpl,
		unsigned char *	cpack,
		g2int *	lcpack
	)

This subroutine packs up a data field using the simple packing algorithm as defined in the GRIB2 documention.

It also fills in GRIB2 Data Representation Template 5.0 with the appropriate values.

Parameters

fld	Contains the data values to pack.
ndpts	The number of data values in array fld.
idrstmpl	Contains the array of values for [Data Representation Template 5.0](https://www.nco.ncep.noaa.gov/pmb/docs/grib2/grib2_doc/grib2_temp5-0.shtml). 0 Reference value - ignored on input - set by simpack routine. 1 Binary Scale Factor - unchanged from input. 2 Decimal Scale Factor - unchanged from input. 3 Number of bits used to pack data, if value is > 0 and <= 31. If this input value is 0 or outside above range then the num of bits is calculated based on given data and scale factors. 4 Original field type - currently ignored on input. Data values assumed to be reals. Set to 0 by simpack routine.
cpack	The packed data field
lcpack	length of packed field starting at cpack.

Author: Stephen Gilbert

Date: 2002-11-06

Definition at line 34 of file simpack.c.

References int_power(), mkieee(), sbit(), and sbits().

Referenced by g2_addfield(), and specpack().

◆ specpack()

void specpack	(	g2float *	fld,
		g2int	ndpts,
		g2int	JJ,
		g2int	KK,
		g2int	MM,
		g2int *	idrstmpl,
		unsigned char *	cpack,
		g2int *	lcpack
	)

This subroutine packs a spectral data field using the complex packing algorithm for spherical harmonic data as defined in the GRIB2 Data Representation Template 5.51.

Parameters

fld	Contains the data values to be packed.
ndpts	The number of data values to pack.
JJ	J - pentagonal resolution parameter.
KK	K - pentagonal resolution parameter.
MM	M - pentagonal resolution parameter.
idrstmpl	Contains the array of 10 values for [Data Representation Template 5.51](https://www.nco.ncep.noaa.gov/pmb/docs/grib2/grib2_doc/grib2_temp5-51.shtml).
cpack	Pointer that gets the packed data field. Must be allocated by caller.
lcpack	length of packed field cpack.

Author: Stephen Gilbert

Date: 2002-12-19

Definition at line 33 of file specpack.c.

References mkieee(), and simpack().

Referenced by g2_addfield().

Functions

Detailed Description

Function Documentation

◆ cmplxpack()

◆ g2_addfield()

Program History Log

◆ getdim()

◆ getpoly()

◆ jpcpack()

Program History Log

◆ pngpack()

◆ simpack()

◆ specpack()