R: Test set of points for inside/outside polygon

inpoly {GEOmap} | R Documentation

## Test set of points for inside/outside polygon

### Description

takes a set of points and tests with function inside()

### Usage

    inpoly(x, y, POK)

### Arguments

`x` | x coordinates
`y` | y coordinates
`POK` | polygon structure list x,y

### Value

Returns vector of 0,1 for points inside polygon

### Author(s)

Jonathan M. Lees <jonathan.lees@unc.edu>

### See Also

Lintersect, ccw, inside

### Examples

    H=list()
    H$x=c(-0.554,-0.258,0.062,0.538,0.701,0.332,
    0.34,0.26,-0.189,0.081,0.519,0.644,0.264,
    -0.086,-0.216,-0.246,-0.356,-1.022,-0.832,
    -0.372,-0.463,-0.604)
    H$y=c(0.047,-0.4,-0.818,-0.822,-0.314,-0.25,
    -0.491,-0.589,-0.396,-0.138,0.082,0.262,0.542,
    0.361,0.03,0.555,0.869,0.912,0.641,0.327,0.142,0.129)

    plot(c(-1,1), c(-1,1), type='n')

    polygon(H, col=NULL, border=grey(.8))

    x = runif(20, -1,1)
    y =  runif(20, -1,1)
    points(list(x=x, y=y) )

    inp = inpoly(x, y, H)

    text(x[inp==0],y[inp==0], labels="out", pos=1, col='red')
    text(x[inp==1],y[inp==1], labels="in", pos=1, col='blue')

[Package GEOmap version 2.4-0 Index]