insideGEOmapXY function

Get LAT-LON points that fall inside a map

Get LAT-LON points that fall inside a map

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

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)
  • Maintainer: Jonathan M. Lees
  • License: GPL (>= 2)
  • Last published: 2024-07-09

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