Method inverse

SRC/element/PFEMElement/PFEMElement2D.cpp:591–603

}

void
PFEMElement2D::inverse(Matrix& mat) const
{
    double tmp = mat(0,0);
    mat(0,0) = mat(1,1);
    mat(1,1) = tmp;
    mat(0,1) = -mat(0,1);
    mat(1,0) = -mat(1,0);

    tmp = mat(0,0)*mat(1,1)-mat(1,0)*mat(0,1);
    
    mat /= tmp;
}