sl.p2p: Compute Point Between Points on Sphere In helgegoessling/spheRlab: Spherical Geometry, Analysis, and Plotting of Geoscientific Data on Arbitrary Grids

Description

Compute a point on a great-circle line moving a certain fraction from a start point towards an end point.

Usage

 `1` ```sl.p2p(lon1, lat1, lon2, lat2, frac) ```

Arguments

 `lon1` a scalar giving the longitude of the start point. `lat1` a scalar giving the latitude of the start point. `lon2` a scalar giving the longitude of the end point. `lat2` a scalar giving the latitude of the start point. `frac` a scalar giving the fraction how much of the distance from the start point to the end point shall be covered. Values below `0` or above `1` are valid and result in points outside the connecting line between the start and end points.

Value

 `lon` a scalar giving the longitude of the resulting point. `lat` a scalar giving the latitude of the resulting point.

Author(s)

Helge Goessling

`sl.fillequidist`
 ```1 2 3 4 5 6 7``` ```sl.p2p(lon1=0,lat1=0,lon2=90,lat2=40,frac=0.5) ## Should return: ## \$lon ## [1] 37.45372 ## ## \$lat ## [1] 27.03402 ```