Stress and strain principal value

Good Morning,

  I'm writing to you as it seems to me that something is wrong in the presentation of the value of the value of the principal strain and stress.

In a point of the model of my simulation I've found the following values :

stressxx : 0.161759

stressxy : -0.164002

stressxz : -0.306937

stressyy : 328.186

stressyz : 328.75

stresszz : 328.74

Max principal stress :657.213

Mid principal stress: 0.183215

Min principal stress: -0.309

Max principal strain : 0.0158622

Mid principal strain : -0.00313948

Min principal strain : -0.00948482

I've performed some calculations in Matlab and in my opinion the value of the strain should have been

Max principal strain : 0.0095

Mid principal strain : -0.0031

Min principal strain : -0.0031

Here attached are my calculations with matlab.

Maybe there's something wrong in my calculations , but I can't imagine where. 

I would really appreciate a hint