# MAPLE. May 29, 2006. # # Example 4 in HCD table of spherical designs by Munemasa. d := 4; v := [1, 567 , 1680 , 567 , 1 ]; verts := 2816; Q := matrix(d+1,d+1,[ 1, 22, 252, 1386, 1155, 1, 22/3,52/3,-22/3,-55/3, 1, 0, -12, 0, 11, 1,-22/3 52/3, 22/3,-55/3, 1, -22, 252,-1386, 1155 ]); # This tridiagonal matrix, L_1-star, allows us to fill out the cols of Q L := matrix([ [0 , 22 , 0 , 0 , 0 ], [1 , 0 , 21 , 0 , 0 ], [0 , 11/6 , 0 , 121/6 , 0 ], [0 , 0 , 11/3 , 0 , 55/3], [0 , 0 , 0 , 22 , 0 ]]); for h from 2 to d do for i from 1 to d+1 do Q[i,h+1] := solve( Q[i,2]*Q[i,h] = L[h-1,h]*Q[i,h-1]+L[h+1,h]*x); od; od: [0 567 0 0 0] [ ] [1 216 320 30 0] [ ] L_1 = [0 108 351 108 0] [ ] [0 30 320 216 1] [ ] [0 0 0 567 0] [0 0 1680 0 0] [ ] [0 320 1040 320 0] [ ] L_2 = [1 351 976 351 1] [ ] [0 320 1040 320 0] [ ] [0 0 1680 0 0] [0 0 0 567 0] [ ] [0 30 320 216 1] [ ] L_3 = [0 108 351 108 0] [ ] [1 216 320 30 0] [ ] [0 567 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] [ 1 567 1680 567 1 ] [ ] [ 1 189 0 -189 -1 ] [ ] P = [ 1 39 -80 39 1 ] [ ] [ 1 -3 0 3 -1 ] [ ] [ 1 -9 16 -9 1 ] [1 22 252 1386 1155 ] [ ] [1 22/3 52/3 -22/3 -55/3] [ ] Q = [1 0 -12 0 11 ] [ ] [1 -22/3 52/3 22/3 -55/3] [ ] [1 -22 252 -1386 1155 ] [0 22 0 0 0 ] [ ] [1 0 21 0 0 ] [ ] Ls1= [0 11/6 0 121/6 0 ] [ ] [0 0 11/3 0 55/3] [ ] [0 0 0 22 0 ] [0 0 252 0 0 ] [ ] [0 21 0 231 0 ] [ ] Ls2= [1 0 148/3 0 605/3] [ ] [0 11/3 0 745/3 0 ] [ ] [0 0 44 0 208 ] [0 0 0 1386 0 ] [ ] [0 0 231 0 1155 ] [ ] Ls3 =[0 121/6 0 8195/6 0 ] [ ] [1 0 745/3 0 3410/3] [ ] [0 22 0 1364 0 ] [0 0 0 0 1155 ] [ ] [0 0 0 1155 0 ] [ ] Ls4 =[0 0 605/3 0 2860/3] [ ] [0 55/3 0 3410/3 0 ] [ ] [1 0 208 0 946 ]