// For Volume Elements
#region Volume Terms
public static double[,] ComputeMassMatrix(PolyMatrix N, Point a, Point b)
{
if (N.Rows > 1)
{
throw new Exception("N must be 1 row x n cols");
}
N = N.Transpose() * N;
var Me = N.Integrate(a, b);
return(Me);
}
