SourceMorph

Namespace: INVLIB  ·  Library: Inverse Library

Python equivalent

mne.SourceMorph in MNE-Python.

#include <inv/source_morph.h>

class INVLIB::SourceMorph

Morphs source estimates from one subject's source space to another.

Usage:

src/examples/ex_inv_api/main.cpp

// Morph the 70 V1 sources onto 35 targets by averaging neighbouring pairs (a sphere-based morph map in practice).
SparseMatrix<double> pairAverage(35, 70);
for (int i = 0; i < 35; ++i) {
    pairAverage.insert(i, 2 * i) = 0.5;
    pairAverage.insert(i, 2 * i + 1) = 0.5;
}
SourceMorph morph;
morph.compute(stc.vertices, VectorXi::LinSpaced(35, 0, 34), pairAverage);
const InvSourceEstimate morphed = morph.apply(stc);

---

Public Methods

SourceMorph()

---

compute(verticesFrom, verticesTo, morphMap)

Compute the morphing transformation.

Builds a sparse interpolation matrix that maps source estimate data from one vertex set to another using nearest-neighbor interpolation.

Parameters:

• verticesFrom : const Eigen::VectorXi & Source vertices in the "from" subject's source space.

• verticesTo : const Eigen::VectorXi & Target vertices in the "to" subject's source space.

• morphMap : const Eigen::SparseMatrix< double > & Sparse interpolation matrix (nTo x nFrom), e.g. MNEMorphMap::toEigen().

---

apply(stcFrom)

Apply the morphing to a source estimate.

Parameters:

• stcFrom : const InvSourceEstimate & Source estimate in the "from" subject's space.

Returns:

• InvSourceEstimate — Morphed source estimate in the "to" subject's space.

---

isComputed()

Check if the morph has been computed.

Returns:

• bool — True if the morph matrix is available for apply().

---

nVerticesTo()

Get the number of target vertices.

Returns:

• int — Number of vertices in the target subject's source space.

---

Example

• Full source: src/examples/ex_inv_api/main.cpp
• Build target: ex_inv_api (runs under CTest)
• Data: mne-cpp-test-data

Used in examples

ex_inv_api

Inverse library: minimum-norm estimates, resolution matrices, label time courses, sparse solvers.

src/examples/ex_inv_api/main.cpp, line 219

SourceMorph morph;
morph.compute(stc.vertices, VectorXi::LinSpaced(35, 0, 34), pairAverage);
const InvSourceEstimate morphed = morph.apply(stc);
ok &= expect(morph.isComputed() && morphed.data.rows() == 35 && near(morphed.data(3, 200), 0.5 * (stc.data(6, 200) + stc.data(7, 200)), 1e-12),
             "SourceMorph: the morph matrix maps every time sample");

Authors of this file

• Christoph Dinh <christoph.dinh@mne-cpp.org>