Singular Manual: convexIntersection

| #### D.13.2.15 convexIntersection Procedure from library `gfan.lib` (see gfan_lib). Usage: convexIntersection(c1,c2); c1 cone, c2 cone convexIntersection(c1,p1); c1 cone, p1 polytope convexIntersection(p1,c1); p1 cone, c1 polytope convexIntersection(p1,p2); p1 polytope, p2 polytope convexIntersection(L); L list of cones resp polytopes Return: cone resp polytope, the convex hull of its two input objects Example:
    LIB "gfan.lib";
    intmat M1[2][2]=
    1,0,
    0,1;
    cone c1=coneViaPoints(M1);
    intmat M2[2][2]=
    1,1,
    1,-1;
    cone c2=coneViaPoints(M2);
    intmat M3[2][2]=
    1,0,
    0,-1;
    cone c3=coneViaPoints(M3);
    cone c12=convexIntersection(c1,c2);
    c12;
    ==> AMBIENT_DIM
    ==> 2
    ==> FACETS
    ==> 0, 1,
    ==> 1,-1
    ==> LINEAR_SPAN
    ==>
    ==>
    print(rays(c12));
    ==> 1,0,
    ==> 1,1
    cone c23=convexIntersection(c2,c3);
    c23;
    ==> AMBIENT_DIM
    ==> 2
    ==> FACETS
    ==> 0,-1,
    ==> 1, 1
    ==> LINEAR_SPAN
    ==>
    ==>
    print(rays(c23));
    ==> 1, 0,
    ==> 1,-1
    cone c13=convexIntersection(c1,c3);
    c13;
    ==> AMBIENT_DIM
    ==> 2
    ==> FACETS
    ==> 1,0
    ==> LINEAR_SPAN
    ==> 0,1
    ==>
    print(rays(c13));
    ==> 1,0

User manual for Singular version 4.4.1, 2025, generated by texi2html.