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FiffEvoked

Namespace: FIFFLIB  ·  Library: FIFF Library

Python equivalent

mne.Evoked in MNE-Python.

#include <fiff/fiff_evoked.h>

class FIFFLIB::FiffEvoked

Single averaged evoked response: time axis, data, baseline, channel info and averaging metadata.

Holds one FIFFB_EVOKED block: times, data, first / last sample indices, baseline, kind, nave, comment and the FiffInfo describing the channels. Use FiffEvokedSet for recordings that contain multiple averaging conditions.

src/examples/ex_fiff_api/main.cpp
QFile aveFile(dir + "/sample_audvis-ave.fif");
FiffEvokedSet evokedSet(aveFile); // all conditions of an -ave.fif file
const FiffEvoked& leftAuditory = evokedSet.evoked[0];

Public Methods​

FiffEvoked()​

Constructs a fiff evoked data.

FiffEvoked(p_IODevice, setno, t_baseline, proj, p_aspect_kind)​

Constructs fiff evoked data, by reading from a IO device.

Parameters:

  • p_IODevice : QIODevice & IO device to read from the evoked data set.

  • setno : QVariant The set to pick. Dataset ID number (int) or comment/name (str). Optional if there isonly one data set in file.

  • t_baseline : QPair< float, float > The time interval to apply rescaling / baseline correction. If None do not apply it. If baseline is (a, b). the interval is between "a (s)" and "b (s)". If a is None the beginning of the data is used and if b is None then b is set to the end of the interval. If baseline is equal ot (None, None) all the time interval is used. If None, no correction is applied.

  • proj : bool Apply SSP projection vectors (optional, default = true).

  • p_aspect_kind : fiff_int_t Either "FIFFV_ASPECT_AVERAGE" or "FIFFV_ASPECT_STD_ERR". The type of data to read. Only used if "setno" is a str.

FiffEvoked(p_FiffEvoked)​

Copy constructor.

Parameters:

  • p_FiffEvoked : const FiffEvoked & Fiff evoked data which should be copied.

operator=(other)​

Copy assignment.

Every member has value semantics, so the compiler-generated member-wise assignment is correct. It is declared explicitly because declaring a copy constructor and/or a destructor deprecates the implicitly generated one.

Parameters:

  • other : const FiffEvoked & Object to assign from.

Returns:

~FiffEvoked()​

Destroys the FiffEvoked.

ch_names()​

Returns list of channel names stored in fiff info -> this is to stay consistent with python.

Returns:

  • QStringList — List of channel names.

clear()​

Initializes fiff evoked data.

aspectKindToString()​

Provides the python Evoked string formatted aspect_kind, which is stored in kind: "average" <-> FIFFV_ASPECT_AVERAGE, "standard_error" <-> FIFFV_ASPECT_STD_ERR or "unknown".

Returns:

  • QString — string formatted aspect_kind.

isEmpty()​

Returns whether FiffEvoked is empty.

Returns:

  • bool — true if is empty, false otherwise.

pick_channels(include, exclude)​

fiff_pick_channels_evoked

Pick desired channels from evoked-response data

Parameters:

  • include : const QStringList &

    • Channels to include (if empty, include all available).

  • exclude : const QStringList &

    • Channels to exclude (if empty, do not exclude any).

Returns:

setInfo(p_info, applyProj)​

Set a new fiff measurement info.

Parameters:

  • p_info : const FiffInfo & Info to set.

  • applyProj : bool Apply SSP projection vectors (optional, default = true).

operator+=(newData)​

Inputs a new data set and recalculates the average.

This function also iterates the nave parameter by one.

Parameters:

  • newData : const Eigen::MatrixXd & the new data set which is to be added to the current average.

Returns:

applyBaselineCorrection(p_baseline)​

Applies baseline correction to the evoked data.

Parameters:

  • p_baseline : QPair< float, float > & time definition of the baseline in seconds [from, to].

Static Methods​

read(p_IODevice, p_FiffEvoked, setno, t_baseline, proj, p_aspect_kind)​

fiff_read_evoked

Wrapper for the FiffEvokedDataSet::read_evoked static function

Read one evoked data set

Parameters:

  • p_IODevice : QIODevice & An fiff IO device like a fiff QFile or QTCPSocket.

  • p_FiffEvoked : FiffEvoked & The read evoked data.

  • setno : QVariant the set to pick. Dataset ID number (int) or comment/name (str). Optional if there isonly one data set in file.

  • t_baseline : QPair< float, float > The time interval to apply rescaling / baseline correction. If None do not apply it. If baseline is (a, b). the interval is between "a (s)" and "b (s)". If a is None the beginning of the data is used and if b is None then b is set to the end of the interval. If baseline is equal ot (None, None) all the time interval is used. If None, no correction is applied.

  • proj : bool Apply SSP projection vectors (optional, default = true).

  • p_aspect_kind : fiff_int_t Either "FIFFV_ASPECT_AVERAGE" or "FIFFV_ASPECT_STD_ERR". The type of data to read. Only used if "setno" is a str.

Returns:

  • bool — true if successful, false otherwise.

combine(evokeds, weights)​

Merges evoked data by weighted addition or subtraction (mne.combine_evoked).

All data sets must have the same channels and time instants. The result carries the union of the bad channels, the weighted sum of the data, a comment such as "0.474 × A + 0.526 × B" and nave = 1 / sum(w_i^2 / nave_i), rounded to an integer as required by the FIFF format.

Parameters:

  • evokeds : const QList< FiffEvoked > & The evoked data sets.

  • weights : const Eigen::VectorXd & One weight per data set.

Returns:

combine(evokeds, weights)​

Merges evoked data with a predefined weighting strategy (weights="nave" or "equal").

Parameters:

  • evokeds : const QList< FiffEvoked > & The evoked data sets.

  • weights : CombineWeights The weighting strategy.

Returns:

Example​

Used in examples​

ex_clustered_inverse_pwl_rap_music_raw​

Example of the computation of a raw clustered inverse Powell RAP-MUSIC.

src/examples/ex_clustered_inverse_pwl_rap_music_raw/main.cpp, line 420
FiffEvoked evoked = data.average(raw.info, tmin * raw.info.sfreq, floor(tmax * raw.info.sfreq + 0.5), vecSel);

ex_clustered_inverse_rap_music_raw​

Example of the computation of a raw clustered inverse rap music.

src/examples/ex_clustered_inverse_rap_music_raw/main.cpp, line 415
FiffEvoked evoked = data.average(raw.info, tmin * raw.info.sfreq, floor(tmax * raw.info.sfreq + 0.5), vecSel);

ex_fiff_api​

FIFF library: measurement info, channels, digitizer, transforms, projectors, covariance, events,.

src/examples/ex_fiff_api/main.cpp, line 199
QFile aveFile(dir + "/sample_audvis-ave.fif");
FiffEvokedSet evokedSet(aveFile); // all conditions of an -ave.fif file
const FiffEvoked& leftAuditory = evokedSet.evoked[0];
// mne.read_evokeds: 4 conditions, "Left Auditory" nave 55, 376 x 421 samples starting at -0.1998 s
ok &= expect(evokedSet.evoked.size() == 4 && leftAuditory.comment == "Left Auditory" && leftAuditory.nave == 55 && leftAuditory.data.cols() == 421 && std::fabs(leftAuditory.times(0) + 0.19979521f) < 1e-6f,
             "FiffEvokedSet/FiffEvoked: 4 conditions; Left Auditory averages 55 epochs over 421 samples");

Also used in ex_inv_beamformer, ex_inverse_pwl_rap_music, ex_inverse_rap_music, ex_mne_api, ex_averaging, ex_clustered_inverse_mne, ex_clustered_inverse_mne_raw, ex_connectivity, ex_connectivity_comparison, ex_disp_3D, ex_dsp_rt, ex_fiff_structure, ex_histogram, ex_interpolation, ex_inv_api, ex_inv_dipole_fit, ex_inverse_mne, ex_inverse_mne_raw, ex_make_inverse_operator, ex_read_evoked, ex_tf_plot.

Authors of this file​