(ξ1,ξ2,ξ3,ξ4,η1,η2,η3,η4)=
1 1 1 1 1 2 1 0
1 1 -1 -1 1 1 1 1
1 -1 1 -1 0 3 0 -1
1 -1 -1 1 1 1 0 -1
ri-r1,i=2,3,4
1 1 1 1 1 2 1 0
0 0 -2 -2 0 -1 0 1
0 -2 0 -2 -1 1 -1 -1
0 -2 -2 0 0 -1 -1 -1
r4-r2-r3
1 1 1 1 1 2 1 0
0 0 -2 -2 0 -1 0 1
0 -2 0 -2 -1 1 -1 -1
0 0 0 4 1 -1 0 -1
r4*(-1/4), r1-r4,r2+2r4,r3+2r4
1 1 1 0 3/4 9/4 1 1/4
0 0 -2 0 2/4 -6/4 0 2/4
0 -2 0 0 -2/4 2/4 -1 -6/4
0 0 0 1 1/4 -1/4 0 -1/4
r2*(-1/2),r3*(-1/2)
1 1 1 0 3/4 9/4 1 1/4
0 0 1 0 -1/4 3/4 0 -1/4
0 1 0 0 1/4 -1/4 1/2 3/4
0 0 0 1 1/4 -1/4 0 -1/4
r1-r2-r3, r2r3
1 0 0 0 3/4 7/4 1/2 -1/4
0 1 0 0 1/4 -1/4 1/2 3/4
0 0 1 0 -1/4 3/4 0 -1/4
0 0 0 1 1/4 -1/4 0 -1/4
过渡矩阵为
3/4 7/4 1/2 -1/4
1/4 -1/4 1/2 3/4
-1/4 3/4 0 -1/4
1/4 -1/4 0 -1/4