%  Example problem in Text

%  Strain Tensor

eps = [ -750 -800 -525
        -800 -800 -300
        -525 -300  900 ]
    
%  Coordinate Transform

i1 = [-0.8 -0.6 0]';
j1 = [ 0.0  0.0 -1]';
k1 = [ 0.6 -0.8 0]';

Q = [ i1 j1 k1]

%  Strain Transformation

eps_prime = Q' * eps * Q