File:Relative neighborhood graph.svg
Summary
| Description |
English: The relative neighborhood graph of 100 random points in a square |
| Date | |
| Source | Own work |
| Author | David Eppstein |
Licensing
 |
I, the copyright holder of this work, release this work into the public domain. This applies worldwide. In some countries this may not be legally possible; if so: I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law. |
Source code
This image was created with the following Python source code and then recolored and converted to SVG in Adobe Illustrator.
from pyx import canvas,path,color
from math import *
from random import seed,random
seed(12345)
npoints = 100
radius = 0.05
exclusion = 0.2 # prevent points from being too close
scale = 5
beta1 = 1.1
beta2 = 0.9
theta1 = asin(1/beta1)
theta2 = pi - asin(beta2)
def dist2(p,q):
return (p[0]-q[0])**2 + (p[1]-q[1])**2
points = []
while len(points) < 100:
p = (random()*scale,random()*scale)
if points:
nn = min(dist2(p,q)**0.5 for q in points)
if nn < exclusion:
continue
points.append(p)
def neighbors(p,q):
for r in points:
if max(dist2(p,r),dist2(q,r)) < dist2(p,q):
return False
return True
c = canvas.canvas()
def edge(p,q):
c.stroke(path.line(p[0],p[1],q[0],q[1]),
[color.rgb.black])
def point(p):
c.fill(path.circle(p[0],p[1],radius),[color.rgb.red])
for p in points:
for q in points:
if p < q and neighbors(p,q):
edge(p,q)
for p in points:
point(p)
c.writePDFfile("Relative_neighborhood_graph")