LU Decomposition Assignment One

This assignment is to find the LU decomposition of a symmetric tridiagonal matrix M i.e. decompose M as the product of a lower triangular matrix and an upper triangular matrix. L should have 1's on the main diagonal and one diagonal below the main diagonal. U should have a main diagonal and one diagonal above. Represent M by two ArrayList<Double>, one for the main diagonal and one for the diagonals above and below the main (M is symmetric). The main diagonal is in the file diagonal.txt and the other diagonal is in the file offDiagonal.txt. L should be represented by an ArrayList<Double> lBelow and U by ArrayList<Double> uMain and ArrayList<Double> uAbove. Display all of the ArrayList<Double> in a JTextArea in a JScrollPane in a JOptionPane window along with the original M main diagonal next to the computed M main diagonal.