Hi,

I'm following a technical paper converting the mathematical formula to code and am stuck at the following:

I'm fairly new with the notation and have 2 questions:Given a vector a in R3, we can construct a 3x3 symmetric matrix, m(a) that has |a| as an eigenvalue with a as the corresponding eigenvector, and with the other two eigenvalues equal to zero. This matrix is defined by

m(a) = {aaT/|a| : a != 0

{ 0 : a = 0

1) How do you construct this 3x3 matrix in layman's terms?

2) I have 3 eigenvalues & corresponding eigenvectors gained from a stress matrix that I'm trying to decompose into compressive and tensile forces, does it look as if I should be just selecting one of these to form the above matrix?