Given the MATLAB ex below:

VEC1=rand(1,100)*2;
VEC2=rand(1,100)*20;
VEC3=rand(1,100)*9;
VECS=(VEC1; VEC2; VEC3);

[PCCOEFFS, SCORES, LATENTEIGENVALUES]=princomp(VECS);

I know that each PCCOEFFS column consists of a weighted list of coefficients mapped against each of the constituent source dimensions in VECS.

I also know that LATENTEIGNEVALUES consists of a sorted list of the eigenvalues related to each of the 3 dimensions in VECS.

When I run the above I only get TWO non-zero EIGNEVALUES - how do I tell which of VEC1, VEc2 and VEC3 are the 2 dimensions of interest/greatest gravitas please and which one should I discard/ignore?