[ODE] Old Cholesky factorization code

[Jason Gott]

Greetings,

In the code where the Dantzig LCP solver takes over
(after the A matrix and rhs vector have been
determined), I noticed that there is a commented call
to a Cholesky factorizor and solver.  In block-matrix
form (where each entry is a matrix of the form
J*InvM*Jt), I realize that the A matrix is
block-symmetric, BUT, I was wondering...  Are the
diagonal entries of the block A matrix themselves
actually symmetric (J*InvM*Jt) even after the body has
undergone rotations, making the inverse inertia tensor
non-symmetric?  If not, the Cholesky decomp wouldn't
work, correct?

In other words, did the Cholesky decomp ever work
properly for A?  Or was it just ditched to incorporate
LCP constrains (contacts with friction)?

Thanks!
J

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