mne.minimum_norm.get_point_spread

mne.minimum_norm.get_point_spread(resmat, src, idx, mode=None, n_comp=1, norm=False, return_pca_vars=False, verbose=None)

Get point-spread (PSFs) functions for vertices.

Parameters

resmatarray, shape (n_dipoles, n_dipoles)

Forward Operator.

srcinstance of SourceSpaces

Source space used to compute resolution matrix.

idxlist of int | list of Label

Source for indices for which to compute PSFs or CTFs. If mode is None, PSFs/CTFs will be returned for all indices. If mode is not None, the corresponding summary measure will be computed across all PSFs/CTFs available from idx. Can be:

• list of integers : Compute PSFs/CTFs for all indices to source space vertices specified in idx.

• list of Label : Compute PSFs/CTFs for source space vertices in specified labels.

modeNone | ‘mean’ | ‘max’ | ‘svd’

Compute summary of PSFs/CTFs across all indices specified in ‘idx’. Can be:

• None : Output individual PSFs/CTFs for each specific vertex (Default).

• ‘mean’ : Mean of PSFs/CTFs across vertices.

• ‘max’ : PSFs/CTFs with maximum norm across vertices. Returns the n_comp largest PSFs/CTFs.

• ‘svd’ : SVD components across PSFs/CTFs across vertices. Returns the n_comp first SVD components.

n_compint

Number of PSF/CTF components to return for mode=’max’ or mode=’svd’. Default n_comp=1.

normNone | ‘max’ | ‘norm’

Whether and how to normalise the PSFs and CTFs. This will be applied before computing summaries as specified in ‘mode’. Can be:

• None : Use un-normalized PSFs/CTFs (Default).

• ‘max’ : Normalize to maximum absolute value across all PSFs/CTFs.

• ‘norm’ : Normalize to maximum norm across all PSFs/CTFs.

return_pca_varsbool

Whether or not to return the explained variances across the specified vertices for individual SVD components. This is only valid if mode=’svd’. Default return_pca_vars=False.

verbosebool, str, int, or None

If not None, override default verbose level (see mne.verbose() and Logging documentation for more). If used, it should be passed as a keyword-argument only.

Returns

stcsinstance of SourceEstimate | list of instances of SourceEstimate

PSFs or CTFs as STC objects. All PSFs/CTFs will be returned as successive samples in STC objects, in the order they are specified in idx. STCs for different labels will be returned as a list.

pca_varsarray, shape (n_comp,) | list of array

The explained variances of the first n_comp SVD components across the PSFs/CTFs for the specified vertices. Arrays for multiple labels are returned as list. Only returned if mode=’svd’ and return_pca_vars=True.

Examples using mne.minimum_norm.get_point_spread

Visualize source leakage among labels using a circular graph

Plot point-spread functions (PSFs) and cross-talk functions (CTFs)