Awesome
robust-in-sphere
Exact arithmetic test to check if (n+2) points are cospherical.
(Very) loosely inspired by Jonathan Shewchuk's work on robust predicates. Currently not as fast, but pull requests are welcome.
Example
var inSphere = require("robust-in-sphere")
console.log(inSphere(
[0, 1],
[1, 0],
[-1, 0],
[0, -1]))
Install
npm install robust-in-sphere
API
var inSphere = require("robust-in-sphere")
inSphere(a,b,c,...)
Tests if a collection of n+2
points in n
-dimensional space are cospherical or if the last point is contained in the sphere or not.
a,b,c,...
is a list of points
Returns A signed integer that gives the orientation of the points
<0
if the last point is contained in the oriented sphere defined by the previous two points>0
if the last point is outside the sphere0
is the points are cospherical
Notes Up to 6 points it is possible to get a specialized version of inSphere
that avoids an extra dispatch using the syntax:
inSphere[4](a,b,c,d) === inSphere(a,b,c,d)
Credits
(c) 2014 Mikola Lysenko. MIT License