grib_api: Iterating on latitude/longitude/values

int grib_iterator_delete ( grib_iterator * i )

Frees an iterator from memory.

Parameters:

i

: the iterator

Returns:: 0 if OK, integer value on error

Examples:: iterator.c, and iterator_fortran.F.

int grib_iterator_has_next ( grib_iterator * i )

Test procedure for values in an iterator.

Parameters:

i

: the iterator

Returns:: boolean, 1 if the iterator still nave next values, 0 otherwise

grib_iterator* grib_iterator_new	(	grib_handle *	h,
		unsigned long	flags,
		int *	error
	)

Create a new iterator from a handle, using current geometry and values.

Parameters:

	h	: the handle from which the iterator will be created
	flags	: flags for future use.
	error	: error code

Returns:: the new iterator, NULL if no iterator can be created

Examples:: iterator.c, and iterator_fortran.F.

int grib_iterator_next	(	grib_iterator *	i,
		double *	lat,
		double *	lon,
		double *	value
	)

Get the next value from an iterator.

Parameters:

	i	: the iterator
	lat	: on output latitude in degree
	lon	: on output longitude in degree
	value	: on output value of the point

Returns:: positive value if successful, 0 if no more data are available

Examples:: iterator.c, and iterator_fortran.F.

int grib_iterator_previous	(	grib_iterator *	i,
		double *	lat,
		double *	lon,
		double *	value
	)

Get the previous value from an iterator.

Parameters:

	i	: the iterator
	lat	: on output latitude in degree
	lon	: on output longitude in degree
	value	: on output value of the point*

Returns:: positive value if successful, 0 if no more data are available

int grib_iterator_reset ( grib_iterator * i )

Test procedure for values in an iterator.

Parameters:

i

: the iterator

Returns:: 0 if OK, integer value on error

int grib_nearest_delete ( grib_nearest * nearest )

Frees an nearest from memory.

Parameters:

nearest

: the nearest

Returns:: 0 if OK, integer value on error

Examples:: nearest.c.

int grib_nearest_find	(	grib_nearest *	nearest,
		grib_handle *	h,
		double	inlat,
		double	inlon,
		unsigned long	flags,
		double *	outlats,
		double *	outlons,
		double *	values,
		double *	distances,
		int *	indexes,
		size_t *	len
	)

Find the 4 nearest points of a latitude longitude point.

The flags are provided to speed up the process of searching. If you are sure that the point you are asking for is not changing from a call to another you can use GRIB_NEAREST_SAME_POINT. The same is valid for the grid. Flags can be used together duing an or.

Parameters:

	nearest	: nearest structure
	h	: handle from which geography and data values are taken
	inlat	: latitude of the point to search for
	inlon	: longitude of the point to search for
	flags	: GRIB_NEAREST_SAME_POINT, GRIB_NEAREST_SAME_GRID
	outlats	: returned array of latitudes of the nearest points
	outlons	: returned array of longitudes of the nearest points
	values	: returned array of data values of the nearest points
	distances	: returned array of distances from the nearest points
	indexes	: returned array of indexes of the nearest points
	len	: size of the arrays

Returns:: 0 if OK, integer value on error

Examples:: nearest.c.

int grib_nearest_find_multiple	(	grib_handle *	h,
		int	is_lsm,
		double *	inlats,
		double *	inlons,
		long	npoints,
		double *	outlats,
		double *	outlons,
		double *	values,
		double *	distances,
		int *	indexes
	)

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

If the flag is_lsm is 1 the nearest land point is returned and the grib passed as handle (h) is considered a land sea mask. The land nearest point is the nearest point with land sea mask value>=0.5. If no nearest land points are found the nearest value is returned. If the flag is_lsm is 0 the nearest point is returned. values, distances, indexes (in the "values" array) for the nearest points (ilons,ilats) are returned.

Parameters:

	h	: handle from which geography and data values are taken
	is_lsm	: lsm flag (1-> nearest land, 0-> nearest)
	inlats	: latitudes of the points to search for
	inlons	: longitudes of the points to search for
	npoints	: number of points (size of the inlats,inlons,outlats,outlons,values,distances,indexes arrays)
	outlats	: returned array of latitudes of the nearest points
	outlons	: returned array of longitudes of the nearest points
	values	: returned array of data values of the nearest points
	distances	: returned array of distances from the nearest points
	indexes	: returned array of indexes of the nearest points

Returns:: 0 if OK, integer value on error

grib_nearest* grib_nearest_new	(	grib_handle *	h,
		int *	error
	)

Create a new nearest from a handle, using current geometry .

Parameters:

	h	: the handle from which the iterator will be created
	error	: error code

Returns:: the new nearest, NULL if no nearest can be created

Examples:: nearest.c.

Iterating on latitude/longitude/values

Functions

Detailed Description

Function Documentation


Functions
grib_iterator *	grib_iterator_new (grib_handle h, unsigned long flags, int error)
	Create a new iterator from a handle, using current geometry and values.
int	grib_iterator_next (grib_iterator i, double lat, double lon, double value)
	Get the next value from an iterator.
int	grib_iterator_previous (grib_iterator i, double lat, double lon, double value)
	Get the previous value from an iterator.
int	grib_iterator_has_next (grib_iterator *i)
	Test procedure for values in an iterator.
int	grib_iterator_reset (grib_iterator *i)
	Test procedure for values in an iterator.
int	grib_iterator_delete (grib_iterator *i)
	Frees an iterator from memory.
grib_nearest *	grib_nearest_new (grib_handle h, int error)
	Create a new nearest from a handle, using current geometry .
int	grib_nearest_find (grib_nearest nearest, grib_handle h, double inlat, double inlon, unsigned long flags, double outlats, double outlons, double values, double distances, int indexes, size_t len)
	Find the 4 nearest points of a latitude longitude point.
int	grib_nearest_delete (grib_nearest *nearest)
	Frees an nearest from memory.
int	grib_nearest_find_multiple (grib_handle h, int is_lsm, double inlats, double inlons, long npoints, double outlats, double outlons, double values, double distances, int indexes)
	Find the nearest point of a set of points whose latitudes and longitudes are given in the inlats, inlons arrays respectively.