[Relative Neighborhood Graph Algorithm] Simple RNG graph thanks to ChatGPT #groovy #chatgpt #fiji

Example_RNG.groovy

// DISCLAIMER: The algorithm was taken from a ChatGPT prompt "What is the Groovy implementation of the 2D Relative Neighborhood Graph Algorithm"
// It is merey an alpha version of the code and has not been thorougly tested at all, nor has the code been optimized. 
// The original prompt has been slightly modifided to make better use of ImageJ methods to display the graph


// Create a list of points for testing
def rand = new Random()
// Or to make it reproducible
//def rand = new Random( 1000 )

def points = (1..100).collect{ new Point2D.Double( rand.nextInt( 200 ) + 21,  rand.nextInt( 200 ) + 21 ) }

// Compute the RNG
def rngEdges = getRNG( points )

// Make image to display the results
def imp = IJ.createImage("RNG", "8-bit black", 256, 256, 1);
// Print the edges of the Relative Neighborhood Graph
def ov = new Overlay()

// Make ROIs for each edge and add them to the overlay
rngEdges.each { edge ->
    //Make the point
    def p1 = new PointRoi( edge[0].x, edge[0].y )
    def p2 = new PointRoi( edge[1].x, edge[1].y )
    def link = new Line( edge[0].x, edge[0].y, edge[1].x, edge[1].y )
    ov.add( p1 )
    ov.add( p2 )
    ov.add( link )
    
    // Make the line
    println("Edge: (${edge[0].x}, ${edge[0].y}) - (${edge[1].x}, ${edge[1].y})")
}

imp.setOverlay( ov )
imp.show()



// Actual method to get the RNG
def getRNG( def points) {
	// Create the Relative Neighborhood Graph
	def rngEdges = []
	
	for (int i = 0; i < points.size(); i++) {
	  for (int j = i + 1; j < points.size(); j++) {
	      def p = points[i]
	      def q = points[j]
	
	      if (!hasRNGNeighbor(p, q, points)) {
	          rngEdges << [p, q]
	      }
	  }
	}
	return rngEdges
}


// Function to determine if there's a point z that satisfies RNG condition
def hasRNGNeighbor(Point2D.Double p, Point2D.Double q, List<Point2D.Double> points) {
    for (def z : points) {
        if (z != p && z != q) {
            def dpz = p.distance(z)
            def dqz = q.distance(z)
            if (dpz < p.distance(q) && dqz < p.distance(q)) {
                return true
            }
        }
    }
    return false
}

// Required Imports
import ij.IJ
import java.awt.geom.Point2D
import ij.gui.*