Gauss-Legendre Quadrature Triangle

Performs Gauss-Legendre numerical integral over a standard triangle

Performs Gauss-Legendre numerical integral over a standard triangle defined by the nodes (0,0), (1,0), and (0,1). The code maps a 2D Gauss-Legendre nodes and weights from rectangular domain into a triangle domain. The mapping is performed via bilinear transformation and the quadrature Jacobian.