# MAPLE. June 5. 2006. # # Take dual of coset graph of the shortened extended ternary Golay code. # This is Q-antipodal with r=3. So delete one class to get a new scheme. with(linalg): d := 5; v := [1 , 66 , 132 , 165 , 110 , 12]; verts := 486; Q := matrix([ [1 , 22 , 220 , 220 , 22 , 1], [1 , 7 , 10 , -10 , -7 , -1], [1 , 4 , -5 , -5 , 4 , 1], [1 , -2 , -8 , 8 , 2 , -1], [1 , -5 , 4 , 4 , -5 , 1], [1 , -11 , 55 , -55 , 11 , -1] ]); # This tridiagonal matrix, L_1-star, allows us to fill out the cols of Q # if we are only given the cosines (normalized column 1 of Q). L := matrix([ [0 , 22 , 0 , 0 , 0 , 0], [1 , 1 , 20 , 0 , 0 , 0], [0 , 2 , 13/2 , 27/2 , 0 , 0], [0 , 0 , 27/2 , 13/2 , 2 , 0], [0 , 0 , 0 , 20 , 1 , 1], [0 , 0 , 0 , 0 , 22 , 0] ]); [0 66 0 0 0 0] [ ] [1 0 50 0 15 0] [ ] [0 25 0 40 0 1] L_1 = [ ] [0 0 32 0 34 0] [ ] [0 9 0 51 0 6] [ ] [0 0 11 0 55 0] [0 0 132 0 0 0] [ ] [0 50 0 80 0 2] [ ] [1 0 81 0 50 0] L_2 =[ ] [0 32 0 92 0 8] [ ] [0 0 60 0 72 0] [ ] [0 11 0 110 0 11] [0 0 0 165 0 0] [ ] [0 0 80 0 85 0] [ ] [0 40 0 115 0 10] L_3 =[ ] [1 0 92 0 72 0] [ ] [0 51 0 108 0 6] [ ] [0 0 110 0 55 0] [0 0 0 0 110 0] [ ] [0 15 0 85 0 10] [ ] [0 0 50 0 60 0] L_4 = [ ] [0 34 0 72 0 4] [ ] [1 0 72 0 37 0] [ ] [0 55 0 55 0 0] [0 0 0 0 0 12] [ ] [0 0 2 0 10 0] [ ] [0 1 0 10 0 1] L_5 = [ ] [0 0 8 0 4 0] [ ] [0 6 0 6 0 0] [ ] [1 0 11 0 0 0] [1 66 132 165 110 12] [ ] [1 21 24 -15 -25 -6] [ ] [1 3 -3 -6 2 3] P = [ ] [1 -3 -3 6 2 -3] [ ] [1 -21 24 15 -25 6] [ ] [1 -66 132 -165 110 -12] [1 22 220 220 22 1] [ ] [1 7 10 -10 -7 -1] [ ] [1 4 -5 -5 4 1] Q = [ ] [1 -2 -8 8 2 -1] [ ] [1 -5 4 4 -5 1] [ ] [1 -11 55 -55 11 -1] [0 22 0 0 0 0] [ ] [1 1 20 0 0 0] [ ] [0 2 13/2 27/2 0 0] Ls1 =[ ] [0 0 27/2 13/2 2 0] [ ] [0 0 0 20 1 1] [ ] [0 0 0 0 22 0] [0 0 220 0 0 0] [ ] [0 20 65 135 0 0] [ ] [1 13/2 118 81 27/2 0] Ls2=[ ] [0 27/2 81 118 13/2 1] [ ] [0 0 135 65 20 0] [ ] [0 0 0 220 0 0] [0 0 0 220 0 0] [ ] [0 0 135 65 20 0] [ ] [0 27/2 81 118 13/2 1] Ls3=[ ] [1 13/2 118 81 27/2 0] [ ] [0 20 65 135 0 0] [ ] [0 0 220 0 0 0] [0 0 0 0 22 0] [ ] [0 0 0 20 1 1] [ ] [0 0 27/2 13/2 2 0] Ls4 =[ ] [0 2 13/2 27/2 0 0] [ ] [1 1 20 0 0 0] [ ] [0 22 0 0 0 0] [0 0 0 0 0 1] [ ] [0 0 0 0 1 0] [ ] [0 0 0 1 0 0] Ls5 = [ ] [0 0 1 0 0 0] [ ] [0 1 0 0 0 0] [ ] [1 0 0 0 0 0]