Exact arithmetic test to check if point is contained 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.

`var inSphere = console`

`npm install robust-in-sphere`

`var inSphere = `

`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 sphere`0`

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:

`inSphere4abcd === `

(c) 2014 Mikola Lysenko. MIT License