追赶法Matlab程序

2支棒棒糖

1. function f = Chase(A,f)
   
2. [n,n] = size(A);
   
3. fprintf('追赶法\n');
   
4. L = tril(A);
   
5. U = triu(A,1) + eye(n,n);
   
6. L(1,1) = A(1,1);
   
7. for k = 1:n-1
   
8.     L(k+1,k) = A(k+1,k);
   
9.     U(k,k+1) = A(k,k+1)/L(k,k);
   
10.     L(k+1,k+1) = A(k+1,k+1) - A(k+1,k)*U(k,k+1);
    
11. end
    
12. disp(L);
    
13. disp(U);
    
14. b(1) = A(1,1);
    
15. for k = 2:n
    
16.     a(k) = A(k,k-1);
    
17.     b(k) = A(k,k);
    
18.     c(k-1) = A(k-1,k);
    
19.     B(k-1) = U(k-1,k);
    
20. end
    
21. y(1) = f(1)/b(1);
    
22. for k = 2:n
    
23.     y(k) = (f(k)-a(k)*y(k-1))/(b(k)-a(k)*B(k-1));
    
24. end
    
25. disp(y);
    
26. x(n) = y(n);
    
27. for k = n-1:-1:1
    
28.     x(k) = y(k) - B(k)*x(k+1);
    
29. end
    
30. f = x;
    

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