The numerical computation of the exponentiation of a real matrix has been intensively studied. The main objective of a good numerical method is to deal with round-off errors and computational cost. The situation is more complicated when dealing with interval matrices exponentiation: Indeed, the main problem will now be the dependency loss of the different occurrences of the variables due to interval evaluation, which may lead to so wide enclosures that they are useless. In this paper, the problem of computing a sharp enclosure of the interval matrix exponential is proved to be NP-hard. Then the scaling and squaring method is adapted to interval matrices and shown to drastically reduce the dependency loss w.r.t. the interval evaluation of the Taylor series.
From efficient symplectic exponentiation of matrices to symplectic integration of high-dimensional Hamiltonian systems with slowly varying quadratic stiff potentials
Necessary and sufficient conditions for regularity of interval parametric matrices
矩阵的正则性是解决应用数学中各种问题的关键。用于检验区间参数矩阵正则性的充分条件在参数区间较大时通常会失效。利用边界参数超曲面、参数解集、行列式、实谱半径给出了区间参数矩阵正则性的充要条件。初始的n维K个区间参数问题被大量的1<= t <= min(n-1,K)个区间参数问题所代替,特别是t=1是最有吸引力的.所提出的方法的优点进行了讨论,以及它的应用程序寻找区间壳解决方案的区间参数线性系和确定的正则半径的区间参数矩阵。