GEOmap (version 2.1)

insideGEOmapXY: Get LAT-LON points that fall inside a map

Description

Get LAT-LON points that fall inside a map

Usage

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

Value

• Vector of index values for points that satisfy geographic criteria

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.

Examples

data(japmap)
 PROJfuji = setPROJ(type = 2, LAT0=35.358,LON0=138.731)
plotGEOmapXY(japmap, PROJ=PROJfuji, add=FALSE)
pointsGEOmapXY(gvol$lat, gvol$lon,  PROJ=PROJfuji)
textGEOmapXY(gvol$lat, gvol$lon, gvol$name,  PROJ=PROJfuji, pos=4,
cex=.5)
wv =insideGEOmapXY(gvol$lat, gvol$lon, PROJfuji)
cbind(gvol$name[wv], gvol$lat[wv], gvol$lon[wv])