void SpectClust::normalizeSum(SymmetricMatrix &A) {
  RowVector Ones(A.Ncols());
  Ones = 1.0;
  // Calculate the sum of each row matrix style. Could this be a Diagonal Matrix instead?
  Matrix RowSum = Ones * (A.t());
  DiagonalMatrix D(A.Ncols());
  D = 0;
  // Take the inverse square root
  for(int i = 1; i <= A.Ncols(); i++) {
    D(i,i) = 1/sqrt(RowSum(1,i));
  }
  Matrix X = D * (A * D);
  A << X;
}