nearest_gridpoint: Calculates the nearest point on a grid to a reference point
In ztoolbox: Convenient Functions for Daily Work at ZAMG

Description Usage Arguments Details Value

View source: R/nearest_gridpoint.R

Calculates nearest point on a grid to a reference point in longitude, latitude degree decimal.

1	nearest_gridpoint(lon, lat, grid, measure = c("euclidian","haversine"))

`lon, lat`	longitude and latitude of the reference point in degrees decimal.
`grid`	matrix or data.frame with at leats two columns named `lon` and `lat`. The function looks for the nearest grid point to the reference point.
`measure`	method for distance calculation. Currently `euclidian`, which is the default and `haversine` are possible (see details).

The distance of each point on grid is calculated either as a euclidian distance, or with the Haversine Formula, which computes the great-circle distance between two points on a sphere.

An list with components:

`idx`	index of the point nearest to coordinates `lon, lat` on `grid`.
`lon`	longitude of reference point on `grid`.
`lat`	latitude of reference point on `grid`.