Numerical Algorithms ( IF 2.1 ) Pub Date : 2021-05-16 , DOI: 10.1007/s11075-021-01114-9 Leszek Plaskota , Paweł Samoraj
We present an asymptotic analysis of adaptive methods for Lp approximation of functions f ∈ Cr([a, b]), where \(1\le p\le +\infty \). The methods rely on piecewise polynomial interpolation of degree r − 1 with adaptive strategy of selecting m subintervals. The optimal speed of convergence is in this case of order m−r and it is already achieved by the uniform (nonadaptive) subdivision of the initial interval; however, the asymptotic constant crucially depends on the chosen strategy. We derive asymptotically best adaptive strategies and show their applicability to automatic Lp approximation with a given accuracy ε.
中文翻译:
使用渐近最优自适应插值的自动逼近
我们提出的自适应方法的一个渐近分析大号p的函数逼近˚F ∈ Ç - [R([一,b ]),其中\(1个\文件p \文件+ \ infty \) 。这些方法依赖于度数r -1的分段多项式插值以及选择m个子间隔的自适应策略。在这种情况下,最佳收敛速度为m − r并且已经通过初始间隔的统一(非自适应)细分来实现;然而,渐近常数关键取决于所选择的策略。我们得出了渐近最佳的自适应策略,并显示了它们在给定精度ε下对自动L p逼近的适用性。