pyriemann.utils.tangentspace.log_map_logeuclid

pyriemann.utils.tangentspace.log_map_logeuclid(X, Cref)

Project matrices in tangent space by Log-Euclidean logarithmic map.

The projection of a matrix X from SPD/HPD manifold to tangent space by Log-Euclidean logarithmic map according to a SPD/HPD reference matrix \(\mathbf{C}_\text{ref}\) is:

\[\mathbf{X}_\text{new} = \log(\mathbf{X}) - \log(\mathbf{C}_\text{ref})\]

Parameters

Xndarray, shape (…, n, n)

Matrices in SPD/HPD manidold.

Crefndarray, shape (n, n)

The reference SPD matrix.

Returns

X_newndarray, shape (…, n, n)

Matrices projected in tangent space.

Notes

New in version 0.4.