# statsmodels.stats.correlation_tools.FactoredPSDMatrix¶

class statsmodels.stats.correlation_tools.FactoredPSDMatrix(diag, root)[source]

Representation of a positive semidefinite matrix in factored form.

The representation is constructed based on a vector diag and rectangular matrix root, such that the PSD matrix represented by the class instance is Diag + root * root’, where Diag is the square diagonal matrix with diag on its main diagonal.

Parameters: diag (1d array-like) – See above root (2d array-like) – See above

Notes

The matrix is represented internally in the form Diag^{1/2}(I + factor * scales * factor’)Diag^{1/2}, where Diag and scales are diagonal matrices, and factor is an orthogonal matrix.

Methods

 decorrelate(rhs) Decorrelate the columns of rhs. logdet() Returns the logarithm of the determinant of a factor-structured matrix. solve(rhs) Solve a linear system of equations with factor-structured coefficients. to_matrix() Returns the PSD matrix represented by this instance as a full (square) matrix.