# mne.Label¶

class mne.Label(vertices=(), pos=None, values=None, hemi=None, comment='', name=None, filename=None, subject=None, color=None, verbose=None)[source]

A FreeSurfer/MNE label with vertices restricted to one hemisphere.

Labels can be combined with the + operator:

• Duplicate vertices are removed.

• If duplicate vertices have conflicting position values, an error is raised.

• Values of duplicate vertices are summed.

Parameters
verticesarray, shape (N,)

Vertex indices (0 based).

posarray, shape (N, 3) | None

Locations in meters. If None, then zeros are used.

valuesarray, shape (N,) | None

Values at the vertices. If None, then ones are used.

hemi‘lh’ | ‘rh’

Hemisphere to which the label applies.

commentstr

Kept as information but not used by the object itself.

namestr

Kept as information but not used by the object itself.

filenamestr

Kept as information but not used by the object itself.

subject

Name of the subject the label is from.

colorNone | matplotlib color

Default label color and alpha (e.g., (1., 0., 0., 1.) for red).

verbose

If not None, override default verbose level (see mne.verbose() and Logging documentation for more).

Attributes
color

Default label color, represented as RGBA tuple with values between 0 and 1.

commentstr

Comment from the first line of the label file.

hemi‘lh’ | ‘rh’

Hemisphere.

name

A name for the label. It is OK to change that attribute manually.

posarray, shape (N, 3)

Locations in meters.

subject

Subject name. It is best practice to set this to the proper value on initialization, but it can also be set manually.

valuesarray, shape (N,)

Values at the vertices.

verbose

If not None, override default verbose level (see mne.verbose() and Logging documentation for more).

verticesarray, shape (N,)

Vertex indices (0 based)

Methods

 __add__(self, other) Add Labels. __hash__(self, /) Return hash(self). __len__(self) Return the number of vertices. __sub__(self, other) Subtract Labels. center_of_mass(self[, subject, …]) Compute the center of mass of the label. copy(self) Copy the label instance. fill(self, src[, name]) Fill the surface between sources for a source space label. get_tris(self, tris[, vertices]) Get the source space’s triangles inside the label. get_vertices_used(self[, vertices]) Get the source space’s vertices inside the label. morph(self[, subject_from, subject_to, …]) Morph the label. restrict(self, src[, name]) Restrict a label to a source space. save(self, filename) Write to disk as FreeSurfer *.label file. smooth(self[, subject, smooth, grade, …]) Smooth the label. split(self[, parts, subject, subjects_dir, …]) Split the Label into two or more parts.
__add__(self, other)[source]

__hash__(self, /)

Return hash(self).

__len__(self)[source]

Return the number of vertices.

__sub__(self, other)[source]

Subtract Labels.

center_of_mass(self, subject=None, restrict_vertices=False, subjects_dir=None, surf='sphere')[source]

Compute the center of mass of the label.

This function computes the spatial center of mass on the surface as in [1].

Parameters
subject

The subject the label is defined for.

restrict_verticesbool | array of int | instance of SourceSpaces

If True, returned vertex will be one from the label. Otherwise, it could be any vertex from surf. If an array of int, the returned vertex will come from that array. If instance of SourceSpaces (as of 0.13), the returned vertex will be from the given source space. For most accuruate estimates, do not restrict vertices.

subjects_dir

The path to the freesurfer subjects reconstructions. It corresponds to Freesurfer environment variable SUBJECTS_DIR.

surfstr

The surface to use for Euclidean distance center of mass finding. The default here is “sphere”, which finds the center of mass on the spherical surface to help avoid potential issues with cortical folding.

Returns
vertexint

Vertex of the spatial center of mass for the inferred hemisphere, with each vertex weighted by its label value.

Notes

New in version 0.13.

References

1

Larson and Lee, “The cortical dynamics underlying effective switching of auditory spatial attention”, NeuroImage 2012.

copy(self)[source]

Copy the label instance.

Returns
labelinstance of Label

The copied label.

fill(self, src, name=None)[source]

Fill the surface between sources for a source space label.

Parameters
srcSourceSpaces

Source space in which the label was defined. If a source space is provided, the label is expanded to fill in surface vertices that lie between the vertices included in the source space. For the added vertices, pos is filled in with positions from the source space, and values is filled in from the closest source space vertex.

name

Name for the new Label (default is self.name).

Returns
labelLabel

The label covering the same vertices in source space but also including intermediate surface vertices.

get_tris(self, tris, vertices=None)[source]

Get the source space’s triangles inside the label.

Parameters
trisndarray of int, shape (n_tris, 3)

The set of triangles corresponding to the vertices in a source space.

verticesndarray of int, shape (n_vertices,) | None

The set of vertices to compare the label to. If None, equals to np.arange(10242). Defaults to None.

Returns
label_trisndarray of int, shape (n_tris, 3)

The subset of tris used by the label.

get_vertices_used(self, vertices=None)[source]

Get the source space’s vertices inside the label.

Parameters
verticesndarray of int, shape (n_vertices,) | None

The set of vertices to compare the label to. If None, equals to np.arange(10242). Defaults to None.

Returns
label_vertsndarray of in, shape (n_label_vertices,)

The vertices of the label corresponding used by the data.

morph(self, subject_from=None, subject_to=None, smooth=5, grade=None, subjects_dir=None, n_jobs=1, verbose=None)[source]

Morph the label.

Useful for transforming a label from one subject to another.

Parameters
subject_from

The name of the subject of the current label. If None, the initial subject will be taken from self.subject.

subject_tostr

The name of the subject to morph the label to. This will be put in label.subject of the output label file.

smoothint

Number of iterations for the smoothing of the surface data. Cannot be None here since not all vertices are used.

gradeint, list of shape (2,), array, or None

Resolution of the icosahedral mesh (typically 5). If None, all vertices will be used (potentially filling the surface). If a list, values will be morphed to the set of vertices specified in grade[0] and grade[1], assuming that these are vertices for the left and right hemispheres. Note that specifying the vertices (e.g., grade=[np.arange(10242), np.arange(10242)] for fsaverage on a standard grade 5 source space) can be substantially faster than computing vertex locations. If one array is used, it is assumed that all vertices belong to the hemisphere of the label. To create a label filling the surface, use None.

subjects_dir

The path to the freesurfer subjects reconstructions. It corresponds to Freesurfer environment variable SUBJECTS_DIR.

n_jobsint

The number of jobs to run in parallel (default 1). Requires the joblib package.

verbose

If not None, override default verbose level (see mne.verbose() and Logging documentation for more). Defaults to self.verbose.

Returns
labelinstance of Label

The morphed label.

mne.morph_labels

Morph a set of labels.

Notes

This function will set label.pos to be all zeros. If the positions on the new surface are required, consider using mne.read_surface with label.vertices.

restrict(self, src, name=None)[source]

Restrict a label to a source space.

Parameters
srcinstance of SourceSpaces

The source spaces to use to restrict the label.

name

Name for the new Label (default is self.name).

Returns
labelinstance of Label

The Label restricted to the set of source space vertices.

Notes

New in version 0.20.

save(self, filename)[source]

Write to disk as FreeSurfer *.label file.

Parameters
filenamestr

Path to label file to produce.

Notes

Note that due to file specification limitations, the Label’s subject and color attributes are not saved to disk.

smooth(self, subject=None, smooth=2, grade=None, subjects_dir=None, n_jobs=1, verbose=None)[source]

Smooth the label.

Useful for filling in labels made in a decimated source space for display.

Parameters
subject

The name of the subject used. If None, the value will be taken from self.subject.

smoothint

Number of iterations for the smoothing of the surface data. Cannot be None here since not all vertices are used. For a grade of 5 (e.g., fsaverage), a smoothing of 2 will fill a label.

gradeint, list of shape (2,), array, or None

Resolution of the icosahedral mesh (typically 5). If None, all vertices will be used (potentially filling the surface). If a list, values will be morphed to the set of vertices specified in grade[0] and grade[1], assuming that these are vertices for the left and right hemispheres. Note that specifying the vertices (e.g., grade=[np.arange(10242), np.arange(10242)] for fsaverage on a standard grade 5 source space) can be substantially faster than computing vertex locations. If one array is used, it is assumed that all vertices belong to the hemisphere of the label. To create a label filling the surface, use None.

subjects_dir

The path to the freesurfer subjects reconstructions. It corresponds to Freesurfer environment variable SUBJECTS_DIR.

n_jobsint

The number of jobs to run in parallel (default 1). Requires the joblib package.

verbose

If not None, override default verbose level (see mne.verbose() and Logging documentation for more). Defaults to self.verbose.

Returns
labelinstance of Label

The smoothed label.

Notes

This function will set label.pos to be all zeros. If the positions on the new surface are required, consider using mne.read_surface with label.vertices.

split(self, parts=2, subject=None, subjects_dir=None, freesurfer=False)[source]

Split the Label into two or more parts.

Parameters
parts

Number of labels to create (default is 2), or tuple of strings specifying label names for new labels (from posterior to anterior), or ‘contiguous’ to split the label into connected components. If a number or ‘contiguous’ is specified, names of the new labels will be the input label’s name with div1, div2 etc. appended.

subject

Subject which this label belongs to (needed to locate surface file; should only be specified if it is not specified in the label).

subjects_dir

The path to the freesurfer subjects reconstructions. It corresponds to Freesurfer environment variable SUBJECTS_DIR.

freesurferbool

By default (False) split_label uses an algorithm that is slightly optimized for performance and numerical precision. Set freesurfer to True in order to replicate label splits from FreeSurfer’s mris_divide_parcellation.

Returns
labelslist of Label, shape (n_parts,)

The labels, starting from the lowest to the highest end of the projection axis.

Notes

If using ‘contiguous’ split, you must ensure that the label being split uses the same triangular resolution as the surface mesh files in subjects_dir Also, some small fringe labels may be returned that are close (but not connected) to the large components.

The spatial split finds the label’s principal eigen-axis on the spherical surface, projects all label vertex coordinates onto this axis, and divides them at regular spatial intervals.