--- name: "pdstemplates.c" section: "3" platform: "linux" package: "libg2c-dev" version: "2.1.0-2" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/pdstemplates.c" --- # pdstemplates.c(3) Functions for GRIB2 Product Definition Templates used in Section 4 - the Product Definition Section (PDS). ## NAME pdstemplates.c - Functions for GRIB2 Product Definition Templates used in Section 4 - the Product Definition Section (PDS). ## SYNOPSIS `#include 'grib2_int.h'`\ ### Functions **gtemplate** \* **extpdstemplate** (**g2int** number, **g2int** \*list)\ This subroutine generates the remaining octet map for a given Product Definition Template, if required. int **g2c\_get\_pds\_template** (int pds\_template\_num, int \*maplen, int \*map, int \*needext)\ Get PDS template information. int **g2c\_get\_pds\_template\_extension** (int pds\_template\_num, int \*template, int \*extlen, int \*ext)\ Get pds template extension information. static **g2int** **getpdsindex** (**g2int** number)\ This function returns the index of specified Product Definition Template in array templates. **gtemplate** \* **getpdstemplate** (**g2int** number)\ This subroutine returns PDS template information for a specified Product Definition Template. ### Variables static const struct pdstemplate **templatespds** \[**G2C\_MAX\_PDS\_TEMPLATE**\]\ Data for struct for PDS template. ## Detailed Description Functions for GRIB2 Product Definition Templates used in Section 4 - the Product Definition Section (PDS). Each Template has three parts: - 1\. The number of entries in the template (mappdslen). - 2\. A map of the template (mappds), which contains the number of octets in which to pack each of the template values. - 3\. A logical value (needext) that indicates whether the Template needs to be extended. In some cases the number of entries in a template can vary depending upon values specified in the 'static' part of the template. (See Template 4.3 as an example). **Note** Array mappds contains the number of octets in which the corresponding template values will be stored. A negative value in mappds is used to indicate that the corresponding template entry can contain negative values. This information is used later when packing (or unpacking) the template data values. Negative data values in GRIB are stored with the left most bit set to one, and a negative number of octets value in mappds\[\] indicates that this possibility should be considered. The number of octets used to store the data value in this case would be the absolute value of the negative value in mappds. ### Program History Log Date Programmer Comments 2001-06-28 Gilbert Initial 2009-01-14 Vuong Changed structure name template to gtemplate 2009-12-15 Vuong Added Product Definition Templates 4.31, 4.15 2010-08-03 Vuong Added Product Definition Template 4.42 and 4.43 2010-12-08 Vuong Corrected Product Definition Template 4.42 and 4.43 2012-03-29 Vuong Added Templates 4.44,4.45,4.46,4.47,4.48,4.50, 4.51,4.91,4.32 and 4.52 2013-08-05 Vuong Corrected 4.91 and added Templates 4.33,4.34,4.53,4.54 2015-10-07 Vuong Added Templates 4.57, 4.60, 4.61 and allow a forecast time to be negative 2022-10-18 Hartnett Added **g2c\_get\_pds\_template()** and **g2c\_get\_pds\_template\_extension()**. 2024-09-09 Stahl Added extension for Template 4.35 2024-12-04 Stahl Added 55 missing templates, including those from July 2024 WMO updates. **Author** Stephen Gilbert **Date** 2001-06-28 Definition in file **pdstemplates.c**. ## Function Documentation ### gtemplate \* extpdstemplate (g2int number, g2int \* list) This subroutine generates the remaining octet map for a given Product Definition Template, if required. Some Templates can vary depending on data values given in an earlier part of the Template, and it is necessary to know some of the earlier entry values to generate the full octet map of the Template. This function allocates memory in the ext field of the gtemplate struct. This memory must be freed by the caller. **Parameters** *number* number of the Product Definition Template 4.NN that is being requested. \ *list* The list of values for each entry in the the Product Definition Template. **Returns** Pointer to the returned template struct. Returns NULL pointer if template not found. **Author** Stephen Gilbert **Date** 2000-05-11 Definition at line **553** of file **pdstemplates.c**. References **getpdsindex()**, and **getpdstemplate()**. Referenced by **g2\_addfield()**, **g2\_unpack4()**, and **g2c\_get\_pds\_template\_extension()**. ### int g2c\_get\_pds\_template (int pds\_template\_num, int \* maplen, int \* map, int \* needext) Get PDS template information. The PDS template consists of a template map, its length, and, for some templates, an extra extension map, and its length. If an extension is needed, use **g2c\_get\_pds\_template\_extension()** to get it. **Parameters** *pds\_template\_num* The PDS template number. \ *maplen* Pointer that gets the length of the map. Ignored if NULL. \ *map* Pointer that gets the map as an array of int. Memory must be allocated by caller. Ignored if NULL. \ *needext* Pointer that a non-zero value if an extension to this template is needed. Ignored if NULL. **Returns** - • **G2C\_NOERROR** No error. - • **G2C\_ENOTEMPLATE** Template not found. **Author** Ed Hartnett **Date** 10/18/22 Definition at line **1806** of file **pdstemplates.c**. References **G2C\_ENOTEMPLATE**, **G2C\_MAX\_PDS\_TEMPLATE**, **G2C\_NOERROR**, and **templatespds**. Referenced by **g2c\_rw\_section4\_metadata()**. ### int g2c\_get\_pds\_template\_extension (int pds\_template\_num, int \* template, int \* extlen, int \* ext) Get pds template extension information. **Parameters** *pds\_template\_num* The pds template number. \ *template* Pointer to array that contains the template values. \ *extlen* Pointer that gets the length of the extension. Ignored if NULL. \ *ext* Pointer that gets template extension array, if there is one. Memory must be allocated by the caller. Ignored if NULL. **Returns** - • **G2C\_NOERROR** No error. - • **G2C\_EINVAL** Invalid input. - • **G2C\_ENOTEMPLATE** Template not found. - • **G2C\_ENOMEM** Out of memory. **Author** Ed Hartnett **Date** 10/16/22 Definition at line **1731** of file **pdstemplates.c**. References **gtemplate::ext**, **gtemplate::extlen**, **extpdstemplate()**, **G2C\_EINVAL**, **G2C\_ENOMEM**, **G2C\_ENOTEMPLATE**, **G2C\_MAX\_PDS\_TEMPLATE**, **G2C\_NOERROR**, and **templatespds**. ### static g2int getpdsindex (g2int number)` [static]` This function returns the index of specified Product Definition Template in array templates. **Parameters** *number* The number of the Product Definition Template that is being requested. **Returns** Index of PDT in array templates, if template exists. -1, otherwise. **Author** Stephen Gilbert **Date** 2001-06-28 Definition at line **469** of file **pdstemplates.c**. References **G2C\_MAX\_PDS\_TEMPLATE**, **getpdsindex()**, and **templatespds**. Referenced by **extpdstemplate()**, **getpdsindex()**, and **getpdstemplate()**. ### gtemplate \* getpdstemplate (g2int number) This subroutine returns PDS template information for a specified Product Definition Template. The number of entries in the template is returned along with a map of the number of octets occupied by each entry. Also, a flag is returned to indicate whether the template would need to be extended. This function allocates memory for the gtemplate struct, which must be freed by the caller. **Parameters** *number* the number of the Product Definition Template that is being requested. **Returns** Pointer to the returned template struct. Returns NULL pointer if template not found. **Author** Stephen Gilbert **Date** 2000-05-11 Definition at line **504** of file **pdstemplates.c**. References **getpdsindex()**, and **templatespds**. Referenced by **extpdstemplate()**, **g2\_addfield()**, and **g2\_unpack4()**. ## Variable Documentation ### const struct pdstemplate templatespds\[G2C\_MAX\_PDS\_TEMPLATE\]` [static]` Data for struct for PDS template. Definition at line **59** of file **pdstemplates.c**. Referenced by **g2c\_get\_pds\_template()**, **g2c\_get\_pds\_template\_extension()**, **getpdsindex()**, and **getpdstemplate()**. ## Author Generated automatically by Doxygen for NCEPLIBS-g2c from the source code.