azula.linalg.covariance

Covariance matrices.

Classes

Covariance

Abstract covariance matrix.

IsotropicCovariance

Isotropic covariance matrix.

DiagonalCovariance

Diagonal covariance matrix.

FullCovariance

Full covariance matrix.

DPLRCovariance

Diagonal plus low-rank (DPLR) covariance matrix.

KroneckerCovariance

Kronecker-factorized covariance matrix.

Descriptions

class azula.linalg.covariance.Covariance

Abstract covariance matrix.

class azula.linalg.covariance.IsotropicCovariance(lmbda)

Isotropic covariance matrix.

\[\lambda I\]
class azula.linalg.covariance.DiagonalCovariance(D)

Diagonal covariance matrix.

\[\mathrm{diag}(D)\]
class azula.linalg.covariance.FullCovariance(C)

Full covariance matrix.

\[C\]
class azula.linalg.covariance.DPLRCovariance(D, V, S=None)

Diagonal plus low-rank (DPLR) covariance matrix.

\[\mathrm{diag}(D) + V \Sigma V^\top\]

Wikipedia

https://wikipedia.org/wiki/Low-rank_approximation

class azula.linalg.covariance.KroneckerCovariance(C, Qs)

Kronecker-factorized covariance matrix.

\[(Q_1 \otimes \dots \otimes Q_n) \, C \, (Q_1 \otimes \dots \otimes Q_n)^\top\]

where \(Q_i\) are orthonormal matrices for each dimension and \(\otimes\) denotes the Kronecker product.

Wikipedia

https://wikipedia.org/wiki/Kronecker_product