# projectivePointsByIntersection -- computes ideal of projective points by intersecting point ideals

## Synopsis

• Usage:
projectivePointsByIntersection(M,R)
• Inputs:
• M, , in which each column consists of the projective coordinates of a point
• R, a ring, homogeneous coordinate ring of the projective space containing the points
• Outputs:
• a list, grobner basis for ideal of a finite set of projective points

## Description

This function computes the ideal of a finite set of projective points by intersecting the ideals of each point.

 i1 : R = QQ[x,y,z] o1 = R o1 : PolynomialRing i2 : M = transpose matrix{{1,0,0},{0,1,1}} o2 = | 1 0 | | 0 1 | | 0 1 | 3 2 o2 : Matrix ZZ <--- ZZ i3 : projectivePointsByIntersection(M,R) o3 = {y - z, x*z} o3 : List