C =[sqrt(2),0.5*sqrt(0.5),-0.125*2^(-3/2),2^(-5/2)/16;0,2^(1/2),2^(-1/2)/2,-2^(-3/2)/8;0,0,2^(1/2),2^(-1/2)/2;0,0,0,2^(1/2)]
C * C
C =1.41420.3536-0.04420.011001.41420.3536-0.0442001.41420.35360001.4142ans =2.00001.000000.000002.00001.0000-0.0000002.00001.00000002.0000