说明：  列主元素消去法是建立在Gauss消去法基础上的，Gauss消去法是在较强条件下进行的，即要求Ai非奇异(i=1,2,• • • ,n-1)。Gauss消去法是按自然顺序消去法，这样的自然顺序选取的主元的解法在计算机中往往误差过大。
(Out the main elements of elimination is based on Gauss elimination, Gauss elimination is under strong conditions, which requires non-singular Ai (i = 1,2, • • • , n-1). Gauss elimination method is based on the natural order of elimination, such as the natural order of the selected solution PCA errors in the computer often too large.)