--ZusammenfassungThe Range of Values of a Complex Polynomial Over a Complex Interval. We discuss algorithms for the computation of the range of values of a complex interval polynomial over a complex interval. The mathematical results needed are based upon a result by Rivlin [7] valid for the range of values of a complex polynomial over the line segment [0,1]. In the present work we extend his results to an arbitrary line segment in the complex plane. Based upon these results we then generate algorithms suitable for both line segments and rectangular regions in the complex plane executed in rectangular complex interval arithmetic. The algorithms are then tested on a variety of complex interval polynomials and compared both to the true rafige of values and to the values obtained by the Horner scheme.
Der Wertevorrat eines komplexen Polynoms in einen komplexen
Interval AnalysisInterval analysis is now a well established subject [31, [5] and here we will only introduce some notation. The set of closed intervals on the real line R will be denoted by I (R). The set of polynomials with coefficients in 1 (R) will be denoted by I P (R).The complex plane is denoted by C. If zl, z 2 ~ C, re (zl) <_ re (Zz) and im (zl) _< im (z2) then we call [zl, z21 a rectangular complex interval. The set of rectangular complex intervals is denoted by R C (C) (see [81, [-10]). If z s C and r s R then [z, r] is called a circular complex interval. The set of circular complex intervals is denoted by C I (C) (see [31, [4]).The elementary operations on elements from 1 (R) and 1P (R) are described in [51.The operations on elements from RI (C) are described in [101 and the operations 0010-485X/79/0022/0153/$ 03.40