三对角线矩阵 meaning in English

tridiagonal matrix
triple diagonal matrix

This can be extended to nxn tridiagonal matrix with l, u bidiagonal .
把它推广到nxn三对角线矩阵使具有两对角线的矩阵L、U。
This can be extended to nxn tridiagonal matrix with l , u bidiagonal
把它推广到nxn三对角线矩阵使具有两对角线的矩阵l 、 u 。
And in the second part , we consider the following four inverse eigenproblems : the reconstruction of normal five - diagonal matrix by two or three ordered eigenvalues and corresponding eigenvectors , and the reconstruction of real symmetric tridiagonal matrix and irreducible real symmetric tridiagonal matrix by three eigenvalues and corresponding eigenvectors , some sufficient conditions for existence of unique solution to the problems are given here , and some necessary and sufficient conditions for the existence of both unique solution and solution ( not unique ) to the latter are also given
第二个部分则讨论四类矩阵逆特征值问题：在考虑给定的两个或三个特征值次序的情况下构造唯一的规范五对角线矩阵：由三个给定的特征值和相应特征向量来构造唯一的实对称三对角线矩阵和不可约实对称三对角线矩阵。文章中给出了前者有唯一解的充分条件以及后者有唯一解和有解(不唯一)的充要条件，并且分别给出了其中唯一解的表达方式。