eccodes::codes_grib_find_nearest Interface Reference

Find the nearest point/points of a given latitude/longitude point. More...

Public Member Functions
subroutine	codes_grib_find_nearest_single (gribid, is_lsm, inlat, inlon, outlat, outlon, value, distance, index, status)
	Find the nearest point of a given latitude/longitude point. More...
subroutine	codes_grib_find_nearest_four_single (gribid, is_lsm, inlat, inlon, outlat, outlon, value, distance, index, status)
	Find the 4 nearest points of a latitude longitude point. More...
subroutine	codes_grib_find_nearest_multiple (gribid, is_lsm, inlats, inlons, outlats, outlons, values, distances, indexes, status)
	Find the nearest point of a set of points whose latitudes and longitudes are given in the inlats, inlons arrays respectively. More...

Detailed Description

Find the nearest point/points of a given latitude/longitude point.

The value in the nearest point (or the four nearest points) is returned as well as the zero based index (which can be used in codes_get_element) and its distance from the given point using the following formula radius * acos( sin(lat1)*sin(lat2)+cos(lat1)*cos(lat2)*cos(lon1-lon2) ).

If the is_lsm flag is .true. the input field gribid is considered as a land sea mask and the nearest land point is returned.
The nearest land point among the four neighbours is:

• the nearest point with land sea mask value >= 0.5
• the nearest without any other condition if all the four have land sea mask value <0.5.

Arrays (real(8)) of latitude/longitude can be provided to find with one call the values,indexes and distances for all the lat/lon points listed in the arrays.

If a single latitude/longitude point is provided and outlat,outlon,value,distance,index are defined as arrays with four elements the lat/lon coordinates and values, distances and indexes of the four nearest points are returned.

In case of error, if the status parameter (optional) is not given, the program will exit with an error message.
Otherwise the error message can be gathered with codes_get_error_string.

Examples: grib_nearest.f90

Parameters

[in]	gribid	id of the grib loaded in memory
[in]	is_lsm	.true. if the nearest land point is required otherwise .false.
[in]	inlat	latitude of the point in degrees
[in]	inlon	longitudes of the point in degrees
[out]	outlat	latitude of the nearest point in degrees
[out]	outlon	longitude of the nearest point in degrees
[out]	distance	distance between the given point and its nearest (in km)
[out]	index	zero based index
[out]	value	value of the field in the nearest point
[out]	status	CODES_SUCCESS if OK, integer value on error

Member Function/Subroutine Documentation

subroutine codes_grib_find_nearest_four_single	(	integer(kind=kindofint), intent(in)	gribid,
		logical, intent(in)	is_lsm,
		real(kind = kindofdouble), intent(in)	inlat,
		real(kind = kindofdouble), intent(in)	inlon,
		real(kind = kindofdouble), dimension(4), intent(out)	outlat,
		real(kind = kindofdouble), dimension(4), intent(out)	outlon,
		real(kind = kindofdouble), dimension(4), intent(out)	value,
		real(kind = kindofdouble), dimension(4), intent(out)	distance,
		integer(kind = kindofint), dimension(4), intent(out)	index,
		integer(kind=kindofint), intent(out), optional	status
	)

Find the 4 nearest points of a latitude longitude point.

In case of error, if the status parameter (optional) is not given, the program will exit with an error message.
Otherwise the error message can be gathered with codes_get_error_string.

Parameters

gribid	id of the GRIB loaded in memory
is_lsm	.true. if the nearest land point is required otherwise .false.
inlat	latitude of the point
inlon	longitudes of the point
outlat	latitude of the nearest point
outlon	longitude of the nearest point
distance	distance between the given point and its nearest
index	zero based index
value	value of the field in the nearest point
status	CODES_SUCCESS if OK, integer value on error

subroutine codes_grib_find_nearest_multiple	(	integer(kind=kindofint), intent(in)	gribid,
		logical, intent(in)	is_lsm,
		real(kind = kindofdouble), dimension(:), intent(in)	inlats,
		real(kind = kindofdouble), dimension(:), intent(in)	inlons,
		real(kind = kindofdouble), dimension(:), intent(out)	outlats,
		real(kind = kindofdouble), dimension(:), intent(out)	outlons,
		real(kind = kindofdouble), dimension(:), intent(out)	values,
		real(kind = kindofdouble), dimension(:), intent(out)	distances,
		integer(kind = kindofint), dimension(:), intent(out)	indexes,
		integer(kind=kindofint), intent(out), optional	status
	)

Find the nearest point of a set of points whose latitudes and longitudes are given in the inlats, inlons arrays respectively.

In case of error, if the status parameter (optional) is not given, the program will exit with an error message.
Otherwise the error message can be gathered with codes_get_error_string.

Parameters

gribid	id of the grib loaded in memory
is_lsm	.true. if the nearest land point is required otherwise .false.
inlats	input real(8) array of the latitudes of the points
inlons	input real(8) array of the longitudes of the points
outlats	output real(8) array of the latitudes of the nearest points
outlons	output real(8) array of the longitudes of the nearest points
distances	output real(8) array of the distances
indexes	output integer(4) array of the zero based indexes
values	output real(8) array of the values
status	CODES_SUCCESS if OK, integer value on error

subroutine codes_grib_find_nearest_single	(	integer(kind=kindofint), intent(in)	gribid,
		logical, intent(in)	is_lsm,
		real(kind = kindofdouble), intent(in)	inlat,
		real(kind = kindofdouble), intent(in)	inlon,
		real(kind = kindofdouble), intent(out)	outlat,
		real(kind = kindofdouble), intent(out)	outlon,
		real(kind = kindofdouble), intent(out)	value,
		real(kind = kindofdouble), intent(out)	distance,
		integer(kind = kindofint), intent(out)	index,
		integer(kind=kindofint), intent(out), optional	status
	)

Find the nearest point of a given latitude/longitude point.

In case of error, if the status parameter (optional) is not given, the program will exit with an error message.
Otherwise the error message can be gathered with codes_get_error_string.

Parameters

gribid	id of the grib loaded in memory
is_lsm	.true. if the nearest land point is required otherwise .false.
inlat	latitude of the point
inlon	longitudes of the point
outlat	latitude of the nearest point
outlon	longitude of the nearest point
distance	distance between the given point and its nearest
index	zero based index
value	value of the field in the nearest point
status	CODES_SUCCESS if OK, integer value on error

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The documentation for this interface was generated from the following file:

• eccodes_f90.f90