non=[8.235 0.083 0.083; 0.139 4.375 -0.006; 0.148 -0.005 0.837]
d_non=det(non)
sym=[8.240 0.122 0.056 ; 0.122 4.372 -0.002; 0.056 -0.002 0.834]
s_det=det(sym)
