# MAPLE. June 1, ,2006. # # Example 29 in HCD table of spherical designs by Munemasa. # # This is the 24-cell. d := 4; v := [1 , 8 , 6 , 8 , 1 ]; verts := 24; Q := matrix([ [1 , 4 , 9 , 8 , 2], [1 , 2 , 0 , -2 , -1], [1 , 0 , -3 , 0 , 2], [1 , -2 , 0 , 2 , -1], [1 , -4 , 9 , -8 , 2] ]); # This tridiagonal matrix is L1-star. L := matrix([ [0 , 4 , 0 , 0 , 0], [1 , 0 , 3 , 0 , 0], [0 , 4/3 , 0 , 8/3 , 0], [0 , 0 , 3 , 0 , 1], [0 , 0 , 0 , 4 , 0] ]); [0 8 0 0 0] [ ] [1 3 3 1 0] [ ] L_1 = [0 4 0 4 0] [ ] [0 1 3 3 1] [ ] [0 0 0 8 0] [0 0 6 0 0] [ ] [0 3 0 3 0] [ ] L_2 = [1 0 4 0 1] [ ] [0 3 0 3 0] [ ] [0 0 6 0 0] [0 0 0 8 0] [ ] [0 1 3 3 1] [ ] L_3 = [0 4 0 4 0] [ ] [1 3 3 1 0] [ ] [0 8 0 0 0] [0 0 0 0 1] [ ] [0 0 0 1 0] [ ] L_4 = [0 0 1 0 0] [ ] [0 1 0 0 0] [ ] [1 0 0 0 0] [1 8 6 8 1] [ ] [1 4 0 -4 -1] [ ] P = [1 0 -2 0 1] [ ] [1 -2 0 2 -1] [ ] [1 -4 6 -4 1] [1 4 9 8 2] [ ] [1 2 0 -2 -1] [ ] Q= [1 0 -3 0 2] [ ] [1 -2 0 2 -1] [ ] [1 -4 9 -8 2] [0 4 0 0 0] [ ] [1 0 3 0 0] [ ] Ls1 = [0 4/3 0 8/3 0] [ ] [0 0 3 0 1] [ ] [0 0 0 4 0] [0 0 9 0 0] [ ] [0 3 0 6 0] [ ] Ls2 = [1 0 6 0 2] [ ] [0 3 0 6 0] [ ] [0 0 9 0 0] [0 0 0 8 0] [ ] [0 0 6 0 2] [ ] Ls3 = [0 8/3 0 16/3 0] [ ] [1 0 6 0 1] [ ] [0 4 0 4 0] [0 0 0 0 2] [ ] [0 0 0 2 0] [ ] Ls4 = [0 0 2 0 0] [ ] [0 1 0 1 0] [ ] [1 0 0 0 1]