Function setSubMatrix

tests/utils/qmatrix.cpp:203–215

 */

void setSubMatrix(qmatrix &dest, qmatrix sub, size_t r, size_t c) {
    DEMAND( sub.size() > 0 );
    DEMAND( sub   .size() + r <= dest.size() );
    DEMAND( sub[0].size() + c <= dest.size() );

    // this function cheekily supports when 'sub' is non-square,
    // which is inconsistent with the preconditions of most of
    // the qmatrix functions, but is needed by setDensityQuregAmps()

    for (size_t i=0; i<sub.size(); i++)
        for (size_t j=0; j<sub[i].size(); j++)
            dest[r+i][c+j] = sub[i][j];
}

void setSubMatrix(qmatrix &dest, qvector sub, size_t flatInd) {
    DEMAND( sub.size() + flatInd <= dest.size()*dest.size() );