Bilinear interpolation is used so that values will vary smoothly within a
longitude-latitude grid cell. Note that the sign convention for
longitude and latitude must match that in topo.
Usage
topoInterpolate(longitude, latitude, topo)
Value
Vector of heights giving the elevation of the earth above means sea
level at the indicated location on the earth.
Arguments
longitude
Vector of longitudes (in the same sign convention as used in
topo).
latitude
Vector of latitudes (in the same sign convention as used in
topo).
topo
A topo object.
Author
Dan Kelley
See Also
Other things related to topo data:
[[,topo-method,
[[<-,topo-method,
as.topo(),
download.topo(),
plot,topo-method,
read.topo(),
subset,topo-method,
summary,topo-method,
topo-class,
topoWorld