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Copy pathLDLTPiv.m
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LDLTPiv.m
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function [L, D, p] = LDLTPiv(A)
[n, ~] = size(A);
L = eye(n); % Inisialisasi L sebagai matriks identitas
D = zeros(n, 1);
p = 1:n;
for k = 1:n
% Pivoting: Cari elemen diagonal terbesar
[~, v] = max(abs(diag(A(k:n, k:n))));
v = v + k - 1;
if v ~= k
% Tukar baris dan kolom v dan k pada A (pivoting simetris)
A([k, v], :) = A([v, k], :);
A(:, [k, v]) = A(:, [v, k]);
% Tukar elemen pivot
p([k, v]) = p([v, k]);
% Tukar baris pada L hingga kolom ke-(k-1)
if k > 1
L([k, v], 1:k-1) = L([v, k], 1:k-1);
end
end
% Hitung elemen diagonal D
D(k) = A(k, k);
% Hitung elemen-elemen L di bawah diagonal
if k < n
L(k+1:n, k) = A(k+1:n, k) / D(k);
% Perbarui submatriks A untuk iterasi berikutnya
A(k+1:n, k+1:n) = A(k+1:n, k+1:n) - L(k+1:n, k) * D(k) * L(k+1:n, k)';
end
end
end