When A=UTDU=LDLT,\textbf{A}=\textbf{U}^T\textbf{D}\textbf{U}=\textbf{L}\textbf{D}\textbf{L}^T,A=UTDU=LDLT, like Cholesky factorization, we have: d1=a11d_1=a_{11}d1=a11 gij=aij−∑k=1j−1gikljk,(j=1,…,i−1)g_{ij}=a_{ij}-\sum_{k=1}^{j-1}g_{ik}l_{jk}, (j=1,\dots,i-1)