pyriemann.utils.tangentspace.exp_map_euclid

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

Project matrices back to SPD manifold by Euclidean exponential map.

The projection of a matrix X back to the SPD manifold with Euclidean exponential map according to a reference matrix \(\mathbf{C}_\text{ref}\) is:

\[\mathbf{X}_\text{original} = \mathbf{X} + \mathbf{C}_\text{ref}\]

Parameters

Xndarray, shape (…, n_channels, n_channels)

Matrices in tangent space.

Crefndarray, shape (n_channels, n_channels)

The reference SPD matrix.

Returns

X_originalndarray, shape (…, n_channels, n_channels)

SPD matrices.

Notes

New in version 0.3.1.