Re: Plane geometry in PARI

[Charles Greathouse <crgreathouse@gmail.com>]

Note that you could either write a C/C++ program including both the computational geometry library and PARI, or else use a standalone program (possibly preexisting, possibly built using such a library) and bring the results into GP with externstr.

If the PARI part is fast, the latter is easier. If the PARI part is slow, the former may give better performance (and gp2c could help, perhaps).

On Tue, Jan 17, 2023 at 4:57 PM Aurel Page <aurel.page@normalesup.org> wrote:

Hi James,

I don't know of any. But there are many C (or C++) libraries that implement computational geometry, which you would then need to interface with Pari. Note that your two problems are essentially equivalent (by duality).

You wrote "plane geometry" and "R^3". You really meant 3d, not 2d, right?

Best,
Aurel

On 17/01/2023 21:22, James Rickards wrote:

Are there any libraries of methods built on top of PARI which work with plane geometry? The main things that I want to compute are:

• Given a set of points (say in R^3), find their convex hull
• Given a set of planes in R^3, they divide R^3 into regions. Return the connected component of the origin.

Thanks,

James Rickards