Re: [math] getCovariance in SingularValueDecomposition

2014-10-08 Thread Bruce A Johnson
I've figured out what the issue is here. Basically, there is ambiguity in what is meant by the covariance matrix. The getCovariance method in the SingularValueDecomposition class returns a covariance matrix that could be used to describe the covariance between the best-fit parameters obtained

[math] getCovariance in SingularValueDecomposition

2014-10-07 Thread Bruce A Johnson
As I understand it (which could easily be wrong), calculation of the covariance (X'X) via SVD follows the following logic: X = USV'(via SVD, the X' indicates transpose) X'X = (USV')' USV' this reduces to X'X = VSU'USV' = V S S V' In the SingularValueDecomposition class the cova