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

insideGEOmapXY {GEOmap} | R Documentation

## 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

### 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.

### Value

Vector of index values for points that satisfy geographic criteria

### Author(s)

Jonathan M. Lees<jonathan.lees.edu>

### Examples

    ## Not run:

    data('japmap', package='geomapdata' )
    isel1 = which( japmap$STROKES$code != "i" & japmap$STROKES$num>120 )

     PROJfuji = setPROJ(type = 2, LAT0=35.358,LON0=138.731)
    plotGEOmapXY(japmap, PROJ=PROJfuji, SEL=isel1 , 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])

    ## End(Not run)

[Package GEOmap version 2.4-0 Index]