mne.VolSourceEstimate

class mne.VolSourceEstimate(data, vertices=None, tmin=None, tstep=None, subject=None, verbose=None)[source]

Container for volume source estimates.

Parameters
dataarray of shape (n_dipoles, n_times) | tuple, shape (2,)

The data in source space. The data can either be a single array or a tuple with two arrays: “kernel” shape (n_vertices, n_sensors) and “sens_data” shape (n_sensors, n_times). In this case, the source space data corresponds to “numpy.dot(kernel, sens_data)”.

verticesarray

Vertex numbers corresponding to the data.

tminscalar

Time point of the first sample in data.

tstepscalar

Time step between successive samples in data.

subjectstr | None

The subject name. While not necessary, it is safer to set the subject parameter to avoid analysis errors.

verbosebool, str, int, or None

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

See also

SourceEstimate

A container for surface source estimates.

VolVectorSourceEstimate

A container for volume vector source estimates.

MixedSourceEstimate

A container for mixed surface + volume source estimates.

Notes

New in version 0.9.0.

Attributes

times

A timestamp for each sample.

data

Numpy array of source estimate data.

shape

Shape of the data.

subject

(str | None) The subject name.

vertices

(array of shape (n_dipoles,)) The indices of the dipoles in the source space.

Methods

__add__(self, a)

Add source estimates.

__div__(self, a)

Divide source estimates.

__hash__(self, /)

Return hash(self).

__mul__(self, a)

Multiply source estimates.

__neg__(self)

Negate the source estimate.

__sub__(self, a)

Subtract source estimates.

as_volume(self, src[, dest, mri_resolution, …])

Export volume source estimate as a nifti object.

bin(self, width[, tstart, tstop, func])

Return a source estimate object with data summarized over time bins.

copy(self)

Return copy of source estimate instance.

crop(self[, tmin, tmax])

Restrict SourceEstimate to a time interval.

get_peak(self[, tmin, tmax, mode, …])

Get location and latency of peak amplitude.

mean(self)

Make a summary stc file with mean over time points.

plot(self, src[, subject, subjects_dir, …])

Plot Nutmeg style volumetric source estimates using nilearn.

resample(self, sfreq[, npad, window, …])

Resample data.

save(self, fname[, ftype, verbose])

Save the source estimates to a file.

save_as_volume(self, fname, src[, dest, …])

Save a volume source estimate in a NIfTI file.

sqrt(self)

Take the square root.

sum(self)

Make a summary stc file with sum over time points.

time_as_index(self, times[, use_rounding])

Convert time to indices.

to_data_frame(self[, picks, index, …])

Export data in tabular structure as a pandas DataFrame.

transform(self, func[, idx, tmin, tmax, copy])

Apply linear transform.

transform_data(self, func[, idx, tmin_idx, …])

Get data after a linear (time) transform has been applied.

__add__(self, a)[source]

Add source estimates.

__div__(self, a)[source]

Divide source estimates.

__hash__(self, /)

Return hash(self).

__mul__(self, a)[source]

Multiply source estimates.

__neg__(self)[source]

Negate the source estimate.

__sub__(self, a)[source]

Subtract source estimates.

as_volume(self, src, dest='mri', mri_resolution=False, format='nifti1')[source]

Export volume source estimate as a nifti object.

Parameters
srclist

The list of source spaces (should all be of type volume).

dest‘mri’ | ‘surf’

If ‘mri’ the volume is defined in the coordinate system of the original T1 image. If ‘surf’ the coordinate system of the FreeSurfer surface is used (Surface RAS).

mri_resolution: bool

It True the image is saved in MRI resolution. WARNING: if you have many time points the file produced can be huge.

formatstr

Either ‘nifti1’ (default) or ‘nifti2’.

Returns
imginstance Nifti1Image

The image object.

Notes

New in version 0.9.0.

bin(self, width, tstart=None, tstop=None, func=<function mean at 0x7faa9ca718c8>)[source]

Return a source estimate object with data summarized over time bins.

Time bins of width seconds. This method is intended for visualization only. No filter is applied to the data before binning, making the method inappropriate as a tool for downsampling data.

Parameters
widthscalar

Width of the individual bins in seconds.

tstartscalar | None

Time point where the first bin starts. The default is the first time point of the stc.

tstopscalar | None

Last possible time point contained in a bin (if the last bin would be shorter than width it is dropped). The default is the last time point of the stc.

funccallable()

Function that is applied to summarize the data. Needs to accept a numpy.array as first input and an axis keyword argument.

Returns
stcSourceEstimate | VectorSourceEstimate

The binned source estimate.

copy(self)[source]

Return copy of source estimate instance.

crop(self, tmin=None, tmax=None)[source]

Restrict SourceEstimate to a time interval.

Parameters
tminfloat | None

The first time point in seconds. If None the first present is used.

tmaxfloat | None

The last time point in seconds. If None the last present is used.

data

Numpy array of source estimate data.

get_peak(self, tmin=None, tmax=None, mode='abs', vert_as_index=False, time_as_index=False)[source]

Get location and latency of peak amplitude.

Parameters
tminfloat | None

The minimum point in time to be considered for peak getting.

tmaxfloat | None

The maximum point in time to be considered for peak getting.

mode{‘pos’, ‘neg’, ‘abs’}

How to deal with the sign of the data. If ‘pos’ only positive values will be considered. If ‘neg’ only negative values will be considered. If ‘abs’ absolute values will be considered. Defaults to ‘abs’.

vert_as_indexbool

whether to return the vertex index instead of of its ID. Defaults to False.

time_as_indexbool

Whether to return the time index instead of the latency. Defaults to False.

Returns
posint

The vertex exhibiting the maximum response, either ID or index.

latencyfloat

The latency in seconds.

mean(self)[source]

Make a summary stc file with mean over time points.

Returns
stcSourceEstimate | VectorSourceEstimate

The modified stc.

plot(self, src, subject=None, subjects_dir=None, mode='stat_map', bg_img=None, colorbar=True, colormap='auto', clim='auto', transparent='auto', show=True, verbose=None)[source]

Plot Nutmeg style volumetric source estimates using nilearn.

Parameters
srcinstance of SourceSpaces

The source space.

subjectstr | None

The subject name corresponding to FreeSurfer environment variable SUBJECT. If None stc.subject will be used. If that is None, the environment will be used.

subjects_dirstr

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

modestr

The plotting mode to use. Either ‘stat_map’ (default) or ‘glass_brain’. For “glass_brain”, activation absolute values are displayed after being transformed to a standard MNI brain.

bg_imgNiimg-like object | None

The background image used in the nilearn plotting function. If None, it is the T1.mgz file that is found in the subjects_dir. Not used in “glass brain” plotting.

colorbarbool, optional

If True, display a colorbar on the right of the plots.

colormapstr | np.ndarray of float, shape(n_colors, 3 | 4)

Name of colormap to use or a custom look up table. If array, must be (n x 3) or (n x 4) array for with RGB or RGBA values between 0 and 255. Default (‘auto’) uses ‘hot’ for one-sided data and ‘mne’ for two-sided data.

climstr | dict

Colorbar properties specification. If ‘auto’, set clim automatically based on data percentiles. If dict, should contain:

kind‘value’ | ‘percent’

Flag to specify type of limits.

limslist | np.ndarray | tuple of float, 3 elements

Left, middle, and right bound for colormap.

pos_limslist | np.ndarray | tuple of float, 3 elements

Left, middle, and right bound for colormap. Positive values will be mirrored directly across zero during colormap construction to obtain negative control points.

Note

Only sequential colormaps should be used with lims, and only divergent colormaps should be used with pos_lims.

transparentbool | None

If True, use a linear transparency between fmin and fmid. None will choose automatically based on colormap type.

showbool

Show figures if True. Defaults to True.

verbosebool, str, int, or None

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

Notes

Click on any of the anatomical slices to explore the time series. Clicking on any time point will bring up the corresponding anatomical map.

The left and right arrow keys can be used to navigate in time. To move in time by larger steps, use shift+left and shift+right.

New in version 0.17.

resample(self, sfreq, npad='auto', window='boxcar', n_jobs=1, verbose=None)[source]

Resample data.

Parameters
sfreqfloat

New sample rate to use.

npadint | str

Amount to pad the start and end of the data. Can also be “auto” to use a padding that will result in a power-of-two size (can be much faster).

windowstr or tuple

Window to use in resampling. See scipy.signal.resample.

n_jobsint

Number of jobs to run in parallel.

verbosebool, str, int, or None

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

Notes

For some data, it may be more accurate to use npad=0 to reduce artifacts. This is dataset dependent – check your data!

Note that the sample rate of the original data is inferred from tstep.

save(self, fname, ftype='stc', verbose=None)[source]

Save the source estimates to a file.

Parameters
fnamestr

The stem of the file name. The stem is extended with “-vl.stc” or “-vl.w”.

ftypestr

File format to use. Allowed values are “stc” (default), “w”, and “h5”. The “w” format only supports a single time point.

verbosebool, str, int, or None

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

save_as_volume(self, fname, src, dest='mri', mri_resolution=False, format='nifti1')[source]

Save a volume source estimate in a NIfTI file.

Parameters
fnamestr

The name of the generated nifti file.

srclist

The list of source spaces (should all be of type volume).

dest‘mri’ | ‘surf’

If ‘mri’ the volume is defined in the coordinate system of the original T1 image. If ‘surf’ the coordinate system of the FreeSurfer surface is used (Surface RAS).

mri_resolution: bool

It True the image is saved in MRI resolution. WARNING: if you have many time points the file produced can be huge.

formatstr

Either ‘nifti1’ (default) or ‘nifti2’.

New in version 0.17.

Returns
imginstance Nifti1Image

The image object.

Notes

New in version 0.9.0.

sfreq

Sample rate of the data.

shape

Shape of the data.

sqrt(self)[source]

Take the square root.

Returns
stcinstance of SourceEstimate

A copy of the SourceEstimate with sqrt(data).

sum(self)[source]

Make a summary stc file with sum over time points.

Returns
stcSourceEstimate | VectorSourceEstimate

The modified stc.

time_as_index(self, times, use_rounding=False)[source]

Convert time to indices.

Parameters
timeslist-like | float | int

List of numbers or a number representing points in time.

use_roundingbool

If True, use rounding (instead of truncation) when converting times to indices. This can help avoid non-unique indices.

Returns
indexndarray

Indices corresponding to the times supplied.

times

A timestamp for each sample.

tmin

The first timestamp.

to_data_frame(self, picks=None, index=None, scaling_time=1000.0, scalings=None, copy=True, start=None, stop=None, long_format=False)[source]

Export data in tabular structure as a pandas DataFrame.

Columns and indices will depend on the object being converted. Generally this will include as much relevant information as possible for the data type being converted. This makes it easy to convert data for use in packages that utilize dataframes, such as statsmodels or seaborn.

Parameters
picksstr | list | slice | None

Channels to include. Slices and lists of integers will be interpreted as channel indices. In lists, channel type strings (e.g., ['meg', 'eeg']) will pick channels of those types, channel name strings (e.g., ['MEG0111', 'MEG2623'] will pick the given channels. Can also be the string values “all” to pick all channels, or “data” to pick data channels. None (default) will pick all channels.

indextuple of str | None

Column to be used as index for the data. Valid string options are ‘epoch’, ‘time’ and ‘condition’. If None, all three info columns will be included in the table as categorial data.

scaling_timefloat

Scaling to be applied to time units.

scalingsdict | None

Scaling to be applied to the channels picked. If None, defaults to scalings=dict(eeg=1e6, grad=1e13, mag=1e15, misc=1.0).

copybool

If true, data will be copied. Else data may be modified in place.

startint | None

If it is a Raw object, this defines a starting index for creating the dataframe from a slice. The times will be interpolated from the index and the sampling rate of the signal.

stopint | None

If it is a Raw object, this defines a stop index for creating the dataframe from a slice. The times will be interpolated from the index and the sampling rate of the signal.

long_formatbool

If True, the dataframe is returned in long format where each row is one observation of the signal at a unique coordinate of channels, time points, epochs and conditions. The number of factors depends on the data container. For convenience, a ch_type column is added when using this option that will facilitate subsetting the resulting dataframe. Defaults to False.

Returns
dfinstance of pandas.DataFrame

A dataframe suitable for usage with other statistical/plotting/analysis packages. Column/Index values will depend on the object type being converted, but should be human-readable.

transform(self, func, idx=None, tmin=None, tmax=None, copy=False)[source]

Apply linear transform.

The transform is applied to each source time course independently.

Parameters
funccallable()

The transform to be applied, including parameters (see, e.g., functools.partial()). The first parameter of the function is the input data. The first two dimensions of the transformed data should be (i) vertices and (ii) time. See Notes for details.

idxarray | None

Indices of source time courses for which to compute transform. If None, all time courses are used.

tminfloat | int | None

First time point to include (ms). If None, self.tmin is used.

tmaxfloat | int | None

Last time point to include (ms). If None, self.tmax is used.

copybool

If True, return a new instance of SourceEstimate instead of modifying the input inplace.

Returns
stcsSourceEstimate | VectorSourceEstimate | list

The transformed stc or, in the case of transforms which yield N-dimensional output (where N > 2), a list of stcs. For a list, copy must be True.

Notes

Transforms which yield 3D output (e.g. time-frequency transforms) are valid, so long as the first two dimensions are vertices and time. In this case, the copy parameter must be True and a list of SourceEstimates, rather than a single instance of SourceEstimate, will be returned, one for each index of the 3rd dimension of the transformed data. In the case of transforms yielding 2D output (e.g. filtering), the user has the option of modifying the input inplace (copy = False) or returning a new instance of SourceEstimate (copy = True) with the transformed data.

Applying transforms can be significantly faster if the SourceEstimate object was created using “(kernel, sens_data)”, for the “data” parameter as the transform is applied in sensor space. Inverse methods, e.g., “apply_inverse_epochs”, or “apply_lcmv_epochs” do this automatically (if possible).

transform_data(self, func, idx=None, tmin_idx=None, tmax_idx=None)[source]

Get data after a linear (time) transform has been applied.

The transform is applied to each source time course independently.

Parameters
funccallable()

The transform to be applied, including parameters (see, e.g., functools.partial()). The first parameter of the function is the input data. The first return value is the transformed data, remaining outputs are ignored. The first dimension of the transformed data has to be the same as the first dimension of the input data.

idxarray | None

Indicices of source time courses for which to compute transform. If None, all time courses are used.

tmin_idxint | None

Index of first time point to include. If None, the index of the first time point is used.

tmax_idxint | None

Index of the first time point not to include. If None, time points up to (and including) the last time point are included.

Returns
data_tndarray

The transformed data.

Notes

Applying transforms can be significantly faster if the SourceEstimate object was created using “(kernel, sens_data)”, for the “data” parameter as the transform is applied in sensor space. Inverse methods, e.g., “apply_inverse_epochs”, or “apply_lcmv_epochs” do this automatically (if possible).

tstep

The change in time between two consecutive samples (1 / sfreq).