jacobian_triangle_second Module Function

    module function jacobian_triangle_second(self, i, j, xi, eta) result(Jval)
        implicit none
        class(type_triangle_second), intent(in) :: self
        integer(int32), intent(in) :: i, j
        real(real64), intent(in) :: xi, eta

        real(real64) :: Jval
        integer(int32) :: ii, jlocal

        Jval = 0
        !! dx
        select case (i)
        case (1)
            select case (j)
            case (1)
                !! dx_dxi
                do ii = 1, self%num_nodes
                    Jval = Jval + self%dpsi_dxi(ii, xi, eta) * self%x(ii)%val
                end do
            case (2)
                !! dx_deta
                do ii = 1, self%num_nodes
                    Jval = Jval + self%dpsi_deta(ii, xi, eta) * self%x(ii)%val
                end do
            end select

        !! dy
        case (2)
            select case (j)
            case (1)
                !! dy_dxi
                do ii = 1, self%num_nodes
                    Jval = Jval + self%dpsi_dxi(ii, xi, eta) * self%y(ii)%val
                end do
            case (2)
                !! dy_deta
                do ii = 1, self%num_nodes
                    Jval = Jval + self%dpsi_deta(ii, xi, eta) * self%y(ii)%val
                end do
            end select
        end select

    end function jacobian_triangle_second