insideGEOmapXY(lat, lon, PROJ =NULL, R =NULL, PMAT =NULL)
Arguments
lat: vector of latitudes
lon: vector of longitudes
PROJ: projection structure
PMAT: persp matrix for perspective plot
R: List(lat, lon, radius) for selecting instead of using usr coordinates
Details
The parameters par("usr") is queried and used to select the lat and lons that fall within the mapped region. If the list R=list(lat, lon, radius) is provided, then all indeces of points falling within that radius are returned.
Returns
Vector of index values for points that satisfy geographic criteria