Contains subroutines obtain grid information and the unpacked data (section 3 - 6) for a field from a GRIB2 file. More...

Functions/Subroutines
subroutine	getfield (cgrib, lcgrib, ifldnum, igds, igdstmpl, igdslen, ideflist, idefnum, ipdsnum, ipdstmpl, ipdslen, coordlist, numcoord, ndpts, idrsnum, idrstmpl, idrslen, ibmap, bmap, fld, ierr)
	This subroutine returns the Grid Definition, Product Definition, Bit-map (if applicable), and the unpacked data for a given data field. More...

subroutine	unpack3 (cgrib, lcgrib, iofst, igds, igdstmpl, mapgridlen, ideflist, idefnum, ierr)
	This subroutine unpacks Section 3 (Grid Definition Section) starting at octet 6 of that Section. More...

subroutine	unpack4 (cgrib, lcgrib, iofst, ipdsnum, ipdstmpl, mappdslen, coordlist, numcoord, ierr)
	This subroutine unpacks Section 4 (Product Definition Section) starting at octet 6 of that Section. More...

subroutine	unpack5 (cgrib, lcgrib, iofst, ndpts, idrsnum, idrstmpl, mapdrslen, ierr)
	This subroutine unpacks Section 5 (Data Representation Section) starting at octet 6 of that Section. More...

subroutine	unpack6 (cgrib, lcgrib, iofst, ngpts, ibmap, bmap, ierr)
	This subroutine unpacks Section 6 (Bit-Map Section) starting at octet 6 of that Section. More...

Detailed Description

Contains subroutines obtain grid information and the unpacked data (section 3 - 6) for a field from a GRIB2 file.

Author: Stephen Gilbert

Date: 2000-05-26

Definition in file getfield.F90.

Function/Subroutine Documentation

◆ getfield()

subroutine getfield	(	character(len = 1), dimension(lcgrib), intent(in)	cgrib,
		integer, intent(in)	lcgrib,
		integer, intent(in)	ifldnum,
		integer, dimension(*), intent(out)	igds,
		integer, dimension(*), intent(out)	igdstmpl,
		integer, intent(out)	igdslen,
		integer, dimension(*), intent(out)	ideflist,
		integer, intent(out)	idefnum,
		integer, intent(out)	ipdsnum,
		integer, dimension(*), intent(out)	ipdstmpl,
		integer, intent(out)	ipdslen,
		real, dimension(*), intent(out)	coordlist,
		integer, intent(out)	numcoord,
		integer, intent(out)	ndpts,
		integer, intent(out)	idrsnum,
		integer, dimension(*), intent(out)	idrstmpl,
		integer, intent(out)	idrslen,
		integer, intent(out)	ibmap,
		logical1, dimension(), intent(out)	bmap,
		real, dimension(*), intent(out)	fld,
		integer, intent(out)	ierr
	)

This subroutine returns the Grid Definition, Product Definition, Bit-map (if applicable), and the unpacked data for a given data field.

Since there can be multiple data fields packed into a GRIB2 message, the calling routine indicates which field is being requested with the ifldnum argument.

Parameters

[in]	cgrib	Character array that contains the GRIB2 message.
[in]	lcgrib	Length (in bytes) of GRIB message array cgrib.
[in]	ifldnum	Specifies which field in the GRIB2 message to return.
[out]	igds	Contains information read from the appropriate GRIB Grid Definition Section 3 for the field being returned. Must be dimensioned >= 5. igds(1) Source of grid definition (see Code Table 3.0). igds(2) Number of grid points in the defined grid. igds(3) 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(4) Interpretation of list for optional points definition (Code Table 3.11). igds(5) Grid Definition Template Number (Code Table 3.1).
[out]	igdstmpl	Contains the data values for the specified Grid Definition Template (NN=igds(5)). Each element of this integer array contains an entry (in the order specified) of Grid Defintion Template 3.NN. A safe dimension for this array can be obtained in advance from maxvals(2), which is returned from subroutine gribinfo().
[out]	igdslen	Number of elements in igdstmpl. i.e. number of entries in Grid Defintion Template 3.NN (NN=igds(5)).
[out]	ideflist	(Used if igds(3) .ne. 0) This array contains the number of grid points contained in each row (or column). (part of Section 3) A safe dimension for this array can be obtained in advance from maxvals(3), which is returned from subroutine gribinfo().
[out]	idefnum	(Used if igds(3) .ne. 0) The number of entries in array ideflist - i.e. number of rows (or columns) for which optional grid points are defined.
[out]	ipdsnum	Product Definition Template Number (see Code Table 4.0).
[out]	ipdstmpl	Contains the data values for the specified Product Definition Template (N=ipdsnum). Each element of this integer array contains an entry (in the order specified) of Product Defintion Template 4.N. A safe dimension for this array can be obtained in advance from maxvals(4), which is returned from subroutine gribinfo().
[out]	ipdslen	Number of elements in ipdstmpl - i.e. number of entries in Product Defintion Template 4.N (N=ipdsnum).
[out]	coordlist	Array containg floating point values intended to document the vertical discretisation associated to model data on hybrid coordinate vertical levels (part of Section 4). The dimension of this array can be obtained in advance from maxvals(5), which is returned from subroutine gribinfo().
[out]	numcoord	number of values in array coordlist.
[out]	ndpts	Number of data points unpacked and returned.
[out]	idrsnum	Data Representation Template Number (see Code Table 5.0).
[out]	idrstmpl	Contains the data values for the specified Data Representation Template (N=idrsnum). Each element of this integer array contains an entry (in the order specified) of Product Defintion Template 5.N A safe dimension for this array can be obtained in advance from maxvals(6), which is returned from subroutine gribinfo().
[out]	idrslen	Number of elements in idrstmpl. i.e. number of entries in Data Representation Template specified by idrsnum.
[out]	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.
[out]	bmap	Logical*1 array containing decoded bitmap (if ibmap=0). The dimension of this array can be obtained in advance from maxvals(7), which is returned from subroutine gribinfo().
[out]	fld	Array of ndpts unpacked data points. A safe dimension for this array can be obtained in advance from maxvals(7), which is returned from subroutine gribinfo().
[out]	ierr	Error return code. 0 no error. 1 Beginning characters "GRIB" not found. 2 GRIB message is not Edition 2. 3 The data field request number was not positive. 4 End string "7777" found, but not where expected. 6 GRIB message did not contain the requested number of data fields. 7 End string "7777" not found at end of message. 9 Data Representation Template 5.NN not yet implemented. 10 Error unpacking Section 3. 11 Error unpacking Section 4. 12 Error unpacking Section 5. 13 Error unpacking Section 6. 14 Error unpacking Section 7.

Note: Note that subroutine gribinfo can be used to first determine how many data fields exist in a given GRIB message.

Author: Stephen Gilbert

Date: 2000-05-26

Definition at line 106 of file getfield.F90.

References comunpack(), g2_gbytec(), jpcunpack(), pngunpack(), rdieee(), simunpack(), unpack3(), unpack4(), unpack5(), and unpack6().

◆ unpack3()

subroutine unpack3	(	character(len = 1), dimension(lcgrib), intent(in)	cgrib,
		integer, intent(in)	lcgrib,
		integer, intent(inout)	iofst,
		integer, dimension(*), intent(out)	igds,
		integer, dimension(*), intent(out)	igdstmpl,
		integer	mapgridlen,
		integer, dimension(*), intent(out)	ideflist,
		integer, intent(out)	idefnum,
		integer, intent(out)	ierr
	)

This subroutine unpacks Section 3 (Grid Definition Section) starting at octet 6 of that Section.

Parameters

[in]	cgrib	Character array that contains the GRIB2 message.
[in]	lcgrib	Length (in bytes) of GRIB message array cgrib.
[in,out]	iofst	Bit offset of the beginning (in) or the end (out) of Section 3.
[out]	igds	Contains information read from the appropriate GRIB Grid Definition Section 3 for the field being returned. Must be dimensioned >= 5. igds(1) Source of grid definition (see Code Table - 3.0) igds(2) Number of grid points in the defined grid. igds(3) 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(4) Interpretation of list for optional points definition. (Code Table 3.11). igds(5) Grid Definition Template Number (Code Table 3.1).
[out]	igdstmpl	Contains the data values for the specified Grid Definition Template (NN=igds(5)). Each element of this integer array contains an entry (in the order specified) of Grid Defintion Template 3.NN.
[out]	mapgridlen	Number of elements in igdstmpl - i.e. number of entries in Grid Defintion Template 3.NN (NN=igds(5)).
[out]	ideflist	(Used if igds(3) .ne. 0). This array contains the number of grid points contained in each row (or column) (part of Section 3).
[out]	idefnum	(Used if igds(3) .ne. 0). The number of entries in array ideflist - i.e. number of rows (or columns) for which optional grid points are defined.
[out]	ierr	Error return code. 0 no error. 5 "GRIB" message contains an undefined Grid Definition Template.

Author: Stephen Gilbert

Date: 2000-05-26

Definition at line 374 of file getfield.F90.

References gridtemplates::extgridtemplate(), g2_gbytec(), g2_gbytesc(), and gridtemplates::getgridtemplate().

Referenced by getfield(), and gettemplates().

◆ unpack4()

subroutine unpack4	(	character(len = 1), dimension(lcgrib), intent(in)	cgrib,
		integer, intent(in)	lcgrib,
		integer, intent(inout)	iofst,
		integer, intent(out)	ipdsnum,
		integer, dimension(*), intent(out)	ipdstmpl,
		integer	mappdslen,
		real, dimension(*), intent(out)	coordlist,
		integer, intent(out)	numcoord,
		integer, intent(out)	ierr
	)

This subroutine unpacks Section 4 (Product Definition Section) starting at octet 6 of that Section.

Parameters

[in]	cgrib	Character array that contains the GRIB2 message.
[in]	lcgrib	Length (in bytes) of GRIB message array cgrib.
[in,out]	iofst	Bit offset of the beginning (in) or the end (out) of Section 4.
[out]	ipdsnum	Product Definition Template Number (see Code Table 4.0).
[out]	ipdstmpl	Contains the data values for the specified Product Definition Template (N=ipdsnum). Each element of this integer array contains an entry (in the order specified) of Product Defintion Template 4.N.
[out]	mappdslen	Number of elements in ipdstmpl. i.e. number of entries in Product Defintion Template 4.N (N=ipdsnum).
[out]	coordlist-	Array containg floating point values intended to document the vertical discretisation associated to model data on hybrid coordinate vertical levels (part of Section 4).
[out]	numcoord	number of values in array coordlist.
[out]	ierr	Error return code. 0 no error. 5 GRIB message contains an undefined Product Definition Template.

Author: Stephen Gilbert

Date: 2000-05-26

Definition at line 504 of file getfield.F90.

References pdstemplates::extpdstemplate(), g2_gbytec(), g2_gbytesc(), pdstemplates::getpdstemplate(), and rdieee().

Referenced by getfield(), and gettemplates().

◆ unpack5()

subroutine unpack5	(	character(len = 1), dimension(lcgrib), intent(in)	cgrib,
		integer, intent(in)	lcgrib,
		integer, intent(inout)	iofst,
		integer, intent(out)	ndpts,
		integer, intent(out)	idrsnum,
		integer, dimension(*), intent(out)	idrstmpl,
		integer	mapdrslen,
		integer, intent(out)	ierr
	)

This subroutine unpacks Section 5 (Data Representation Section) starting at octet 6 of that Section.

Parameters

[in]	cgrib	Character array that contains the GRIB2 message.
[in]	lcgrib	Length (in bytes) of GRIB message array cgrib.
[in,out]	iofst	Bit offset of the beginning (in) or the end(out) of Section 5.
[out]	ndpts	Number of data points unpacked and returned.
[out]	idrsnum	Data Representation Template Number (see Code Table 5.0)
[out]	idrstmpl	Contains the data values for the specified Data Representation Template (N = idrsnum). Each element of this integer array contains an entry (in the order specified) of Data Representation Template 5.N.
[out]	mapdrslen	Number of elements in idrstmpl. i.e. number of entries in Data Representation Template 5.N (N = idrsnum).
[out]	ierr	Error return code. 0 no error. 7 GRIB message contains an undefined Data Representation Template.

Author: Stephen Gilbert

Date: 2000-05-26

Definition at line 613 of file getfield.F90.

References drstemplates::extdrstemplate(), g2_gbytec(), and drstemplates::getdrstemplate().

Referenced by getfield().

◆ unpack6()

subroutine unpack6	(	character(len = 1), dimension(lcgrib), intent(in)	cgrib,
		integer, intent(in)	lcgrib,
		integer, intent(inout)	iofst,
		integer, intent(in)	ngpts,
		integer, intent(out)	ibmap,
		logical*1, dimension(ngpts), intent(out)	bmap,
		integer, intent(out)	ierr
	)

This subroutine unpacks Section 6 (Bit-Map Section) starting at octet 6 of that Section.

Parameters

[in]	cgrib	Character array that contains the GRIB2 message.
[in]	lcgrib	Length (in bytes) of GRIB message array cgrib.
[in,out]	iofst	Bit offset of the beginning (in) or the end (out) of Section 6.
[in]	ngpts	Number of grid points specified in the bit-map.
[out]	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.
[out]	bmap	Logical*1 array containing decoded bitmap (if ibmap = 0).
[out]	ierr	Error return code. 0 no error. 4 Unrecognized pre-defined bit-map.

Author: Stephen Gilbert

Date: 2000-05-26

Definition at line 709 of file getfield.F90.

References g2_gbytec(), and g2_gbytesc().

Referenced by getfield().

Functions/Subroutines

Detailed Description

Function/Subroutine Documentation

◆ getfield()

◆ unpack3()

◆ unpack4()

◆ unpack5()

◆ unpack6()