Rotating a Marker Table

[alexbeattie42]

It is common with our measurement setup that the markers need to be globally rotated prior to use.
The java bindings have a way to rotate marker tables:

opensim-core/Bindings/Java/Matlab/Utilities/osimC3D.m

Line 277 in 7f3ec44

function rotateTable(self, table, axisString, value)

OpenSenseUtils contains an orientation table rotation utility:

opensim-core/OpenSim/Simulation/OpenSense/OpenSenseUtilities.h

Line 39 in 7f3ec44

static void rotateOrientationTable(

There should be a similar utility for marker rotation. I usually use a simple function like this but it would be nice to have this as part of the API:

void rotateMarkerTable(
        OpenSim::TimeSeriesTableVec3& table,
        const SimTK::Rotation_<double>& rotationMatrix)
{
    const SimTK::Rotation R_XG = rotationMatrix;

    int nc = int(table.getNumColumns());
    size_t nt = table.getNumRows();

    for (size_t i = 0; i < nt; ++i) {
        auto row = table.updRowAtIndex(i);
        for (int j = 0; j < nc; ++j) {
            row[j] = R_XG * row[j];
        }
    }
    return;
}

[nickbianco]

Short of a dedicated utility, you might be able to leverage Simbody matrix operations, for example, scalarMultiplyFromLeftInPlace().

I've not tested this, but it could possibly even be a one-liner:

table.updMatrix().scalarMultiplyFromLeftInPlace(R);