% The 1 dimension case
format long;
clear;
fprintf('In the 1D case, solve the linear system by direct method.\n');
tic;
e1 = OneD_Case(100);
t = toc;
fprintf('The error with N = 100 is %.8f. The computation takes %.0f seconds of time.\n',e1,t);
tic;
e2 = OneD_Case(200);
t = toc;
fprintf('The error with N = 200 is %.8f. The computation takes %.0f seconds of time.\n',e2,t);
p = log2(e2/e1);
fprintf('The error of the numerical method is O(N^%.0f).\n\n',p);