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MNEDerivSet

Namespace: MNELIB  ·  Library: MNE Library

#include <mne/mne_deriv_set.h>

class MNELIB::MNEDerivSet

Collection of channel derivations.

src/examples/ex_mne_api/main.cpp
// A bipolar EOG-like montage in MNE-C's text syntax, saved as a derivation file and applied while reading raw data
const QString montage = tmp.filePath("montage.txt");
QFile montageFile(montage);
ok &= montageFile.open(QIODevice::WriteOnly | QIODevice::Text);
montageFile.write("\"EEG001-EEG002\" = \"EEG001\" - \"EEG002\"\n\"FRONT\" = 0.5 * \"EEG001\" + 0.5 * \"EEG002\" - \"EEG999\"\n");
montageFile.close();
const auto derivations = MNEDerivSet::readText(montage);
derivations->write(tmp.filePath("montage-deriv.fif"));
const auto fromFif = MNEDerivSet::read(tmp.filePath("montage-deriv.fif"));
const int usable = mneRaw->attachDerivations(*fromFif); // FRONT needs EEG999 and is dropped
MNEChSelection bipolar;
bipolar.chspick = bipolar.chspick_nospace = {"EEG001-EEG002", "EEG001", "EEG002"};
bipolar.nchan = bipolar.ndef = 3;
bipolar.nderiv = 1;
bipolar.pick = (VectorXi(3) << -1, mneRaw->ch_names.indexOf("EEG001"), mneRaw->ch_names.indexOf("EEG002")).finished();
bipolar.pick_deriv = (VectorXi(3) << 0, -1, -1).finished();
mneRaw->proj.reset();
mneRaw->pick_data(&bipolar, mneRaw->first_samp + 2990, ns, rows.data());

Public Methods​

MNEDerivSet()​

MNEDerivSet()​

operator=()​

~MNEDerivSet()​

MNEDerivSet(other)​

Copies the set including every derivation.

Parameters:

  • other : const MNEDerivSet & The set to copy.

operator=(other)​

Replaces the derivations by copies of those of another set.

Parameters:

  • other : const MNEDerivSet & The set to copy.

Returns:

  • MNEDerivSet & — This set.

write(path)​

Writes the set as a FIFFB_MNE_DERIVATIONS block (MNE-C mne_write_deriv_file).

Parameters:

  • path : const QString & The output file.

Returns:

  • bool — True if the file was written; an empty set is not written.

definitions()​

Returns every derivation of the set as definitions, in file order.

Returns:

  • QList< Definition > — Derived channel names with the weights of their inputs.

append(other)​

Appends copies of the derivations of another set (MNE-C mne_merge_deriv_sets).

Parameters:

  • other : const MNEDerivSet & The derivations to append.

match(chNames)​

Keeps the derivations whose inputs are all among chNames and merges them into one derivation whose columns are exactly chNames (MNE-C mne_match_merge_deriv).

Parameters:

  • chNames : const QStringList & Channel names of a recording, in data order.

Returns:

  • std::unique_ptr< MNEDeriv > — The merged derivation with MNEDeriv::in_use set, or nullptr if nothing matched.

count()​

Returns the number of derived channels over all derivations (MNE-C mne_count_deriv).

Returns:

  • int — The total number of rows.

Static Methods​

read(path)​

Reads every derivation stored in the FIFFB_MNE_DERIVATIONS blocks of a file (MNE-C mne_read_deriv).

Parameters:

  • path : const QString & A derivation file written by write() or MNE-C mne_make_derivations.

Returns:

  • std::optional< MNEDerivSet > — The set (empty if the file holds no derivations), or no value if the file cannot be read.

readText(path)​

Reads MNE-C's text syntax (mne_make_derivations in).

Each derivation is name = followed by terms joined by + and -; a term is a channel name optionally preceded by a weight and *, e.g. "EEG 001-EEG 002" = "EEG 001" - "EEG 002". Names with spaces are quoted, tokens are separated by white space and # starts a comment line. Weights of the same input channel add up; derivations whose weights are all zero are dropped.

Parameters:

  • path : const QString & The text file.

Returns:

  • std::optional< MNEDerivSet > — One derivation holding all definitions, or no value on a syntax error.

fromDefinitions(definitions, name)​

Builds one derivation from definitions such as those of dsp::ChannelDerivation.

Parameters:

  • definitions : const QList< Definition > & Derived channel names with the weights of their inputs.

  • name : const QString & Short name of the derivation.

Returns:

  • MNEDerivSet — A set with one derivation; input channels appear in order of first use.

Example​

Used in examples​

ex_mne_api​

MNE library: BEM surfaces, surface projection, ICP, source spaces and epochs.

src/examples/ex_mne_api/main.cpp, line 501
ok &= montageFile.open(QIODevice::WriteOnly | QIODevice::Text);
montageFile.write("\"EEG001-EEG002\" = \"EEG001\" - \"EEG002\"\n\"FRONT\" = 0.5 * \"EEG001\" + 0.5 * \"EEG002\" - \"EEG999\"\n");
montageFile.close();
const auto derivations = MNEDerivSet::readText(montage);
derivations->write(tmp.filePath("montage-deriv.fif"));
const auto fromFif = MNEDerivSet::read(tmp.filePath("montage-deriv.fif"));
const int usable = mneRaw->attachDerivations(*fromFif); // FRONT needs EEG999 and is dropped
MNEChSelection bipolar;
bipolar.chspick = bipolar.chspick_nospace = {"EEG001-EEG002", "EEG001", "EEG002"};
bipolar.nchan = bipolar.ndef = 3;
bipolar.nderiv = 1;
bipolar.pick = (VectorXi(3) << -1, mneRaw->ch_names.indexOf("EEG001"), mneRaw->ch_names.indexOf("EEG002")).finished();
bipolar.pick_deriv = (VectorXi(3) << 0, -1, -1).finished();
mneRaw->proj.reset();

Authors of this file​