Improved Arithmetic of Complex Fans

2021 ◽  
Vol 47 (2) ◽  
pp. 1-10
Author(s):  
Gültekin Soylu

Complex fans are sets of complex numbers whose magnitudes and angles range in closed intervals. The fact that the sum of two fans is a disordered shape gives rise to the need for computational methods to find the minimal enclosing fan. Cases where the sum of two fans contains the origin of the complex plane as a boundary point are of special interest. The result of the addition is then enclosed by circles in current methods, but under certain circumstances this turns out to be an overestimate. The focus of this article is the diagnosis and treatment of such cases.

Author(s):  
A. F. Beardon

AbstractThe unwinding number of a complex number was introduced to process automatic computations involving complex numbers and multi-valued complex functions, and has been successfully applied to computations involving branches of the Lambert W function. In this partly expository note we discuss the unwinding number from a purely topological perspective, and link it to the classical winding number of a curve in the complex plane. We also use the unwinding number to give a representation of the branches $$W_k$$ W k of the Lambert W function as a line integral.


2018 ◽  
Vol 24 (1) ◽  
pp. 20-33 ◽  
Author(s):  
Darius Siaučiūnas ◽  
Violeta Franckevič ◽  
Antanas Laurinčikas

The periodic Hurwitz zeta-function ζ(s, α; a), s = σ +it, with parameter 0 < α ≤ 1 and periodic sequence of complex numbers a = {am } is defined, for σ > 1, by series sum from m=0 to ∞ am / (m+α)s, and can be continued moromorphically to the whole complex plane. It is known that the function ζ(s, α; a) with transcendental orrational α is universal, i.e., its shifts ζ(s + iτ, α; a) approximate all analytic functions defined in the strip D = { s ∈ C : 1/2 σ < 1. In the paper, it is proved that, for all 0 < α ≤ 1 and a, there exists a non-empty closed set Fα,a of analytic functions on D such that every function f ∈ Fα,a can be approximated by shifts ζ(s + iτ, α; a).


2017 ◽  
Vol 70 (3) ◽  
pp. 618-627
Author(s):  
Robin G. Stuart

Mapping points on the Riemann sphere to points on the plane of complex numbers by stereographic projection has been shown to offer a number of advantages when applied to problems in navigation traditionally handled using spherical trigonometry. Here it is shown that the same approach can be used for problems involving great circles and/or rhumb lines and it results in simple, compact expressions suitable for efficient computer evaluation. Worked numerical examples are given and the values obtained are compared to standard references.


1967 ◽  
Vol 60 (7) ◽  
pp. 731-734
Author(s):  
J. Garfunkel

Someone once said that mathematics consists of finding new solutions to old problems and old solutions to new problems. Sometimes, however, it becomes necessary to revive old solutions for old problems. Approximately a hundred years ago C. A. Laisant and other mathematicians of that time used vector methods, with coordinates in the complex plane, to solve certain types of problems in geometry involving polygons having the same centroid, called concentric polygons. This method has been neglected, and it is almost forgotten today. It is the purpose of this article to attempt to revive this method by illustrating its effectiveness in solving certain types of problems in elementary geometry.


1993 ◽  
Vol 86 (7) ◽  
pp. 589-597
Author(s):  
Charles Vonder Embse

Establishing mathematical connections is one of the most important themes that permeates the vision of mathematics teaching as outlined by the Curriculum and Evaluation Standards for School Mathematics (NCTM 1989). A graph has the power to help students make connections between the abstract algebraic representation and the visual representation of a concept, relationship, or pattern. With the introduction of sophisticated graphing utilities and graphing calculators, we can also make connections to the numerical representation as well as the algebraic and graphical representations. Even topics as abstract as complex numbers can now easily be visualized with a graph. Using De Moivre's theorem and a parametric graphing utility, we can graph the powers and roots of complex numbers. The “trace” feature of many graphing utilities moves a point along a graph and gives numerical output, helping students make the connection between the visual and numerical representation of the complex numbers. This rich technological environment allows students to conjecture and test many hypotheses on the way to “discovering” the propertieS of complex numbers represemed in the complex plane.


2020 ◽  
Vol 16 (07) ◽  
pp. 1433-1447
Author(s):  
Gerardo Gonzalez Robert

Good’s Theorem for regular continued fraction states that the set of real numbers [Formula: see text] such that [Formula: see text] has Hausdorff dimension [Formula: see text]. We show an analogous result for the complex plane and Hurwitz Continued Fractions: the set of complex numbers whose Hurwitz Continued fraction [Formula: see text] satisfies [Formula: see text] has Hausdorff dimension [Formula: see text], half of the ambient space’s dimension.


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Daniel A. Nicks ◽  
David J. Sixsmith

AbstractIn the study of discrete dynamical systems, we typically start with a function from a space into itself, and ask questions about the properties of sequences of iterates of the function. In this paper we reverse the direction of this study. In particular, restricting to the complex plane, we start with a sequence of complex numbers and study the functions (if any) for which this sequence is an orbit under iteration. This gives rise to questions of existence and of uniqueness. We resolve some questions, and show that these issues can be quite delicate.


Author(s):  
Juan Carlos Ponce Campuzano

RESUMENExisten diversos métodos para visualizar funciones complejas, tales como graficar por separado sus componentes reales e imaginarios, mapear o transformar una región, el método de superficies analíticas y el método de dominio coloreado. Este último es uno de los métodos más recientes y aprovecha ciertas características del color y su procesamiento digital. La idea básica es usar colores, luminosidad y sombras como dimensiones adicionales, y para visualizar números complejos se usa una función real que asocia a cada número complejo un color determinado. El plano complejo puede entonces visualizarse como una paleta de colores construida a partir del esquema HSV (del inglés Hue, Saturation, Value – Matiz, Saturación, Valor). Como resultado, el método de dominio coloreado permite visualizar ceros y polos de funciones, ramas de funciones multivaluadas, el comportamiento de singularidades aisladas, entre otras propiedades. Debido a las características de GeoGebra en cuanto a los colores dinámicos, es posible implementar en el software el método de dominio coloreado para visualizar y estudiar funciones complejas, lo cual se explica en detalle en el presente artículo.Palabras claves: funciones complejas, método de dominio coloreado, colores dinámicos. RESUMOExistem vários métodos para visualizar funções complexas, como plotar seus componentes reais e imaginários separadamente, mapear ou transformar uma região, o método de superfície analítica e o método de domínio colorido. Este último é um dos métodos mais recentes e aproveita certas características da cor e seu processamento digital. A ideia básica é usar cores e brilho ou sombras como dimensões adicionais e, para visualizar números complexos, é usada uma função real que associa uma cor específica a cada número complexo. O plano complexo pode então ser visualizado como uma paleta de cores construída a partir do esquema HSV (de Matiz, Saturação, Valor - Matiz, Saturação, Valor). Como resultado, o método do domínio colorido permite visualizar zeros e pólos de funções, ramificações de funções com múltiplos valores, o comportamento de singularidades isoladas, entre outras propriedades. Devido às características do GeoGebra em termos de cores dinâmicas, é possível implementar o método do domínio colorido para visualizar e estudar funções complexas, o que é explicado em detalhes neste artigo.Palavras-chave: funções complexas, método de domínio colorido, cores dinâmicas ABSTRACTThere are various methods to visualize complex functions, such as plotting their real and imaginary components separately, mapping or transforming a region, the analytical landscapes method and the domain coloring method. The latter is one of the most recent methods and takes advantage of certain characteristics of color and its digital processing. The basic idea is to use colors and brightness or shadows as additional dimensions and to visualize complex numbers a real function is used that associates a specific color to each complex number. The complex plane can then be visualized as a color palette constructed from the HSV scheme (from Hue, Saturation, Value - Hue, Saturation, Value). As a result, the domain coloring method allows to visualize zeroes and poles of functions, branches of multivalued functions, the behavior of isolated singularities, among others properties. Due to the characteristics of GeoGebra in terms of dynamic colors, it is possible to implement the colored domain method to visualize and study complex functions, which is explained in detail in this article.Keywords:  function; complex; domain; coloring.


2018 ◽  
Vol 7 (4.10) ◽  
pp. 1012
Author(s):  
P. Balamurugan ◽  
A. Gnanam

Gaussian numbers means representation as Complex numbers. In this work, Gaussian Pell numbers are defined from recurrence relation of Pell numbers. Here the recurrence relation on Gaussian Pell number is represented in two dimensional approach. This provides an extension of Pell numbers into the complex plane. 


2021 ◽  
Vol 6 (3 (114)) ◽  
pp. 47-56
Author(s):  
Wasan Saad Ahmed ◽  
Saad Qasim Abbas ◽  
Muntadher Khamees ◽  
Mustafa Musa Jaber

In this paper, the study of the dynamical behavior of logistic map has been disused with representing fractals graphics of map, the logistic map depends on two parameters and works in the complex plane, the map defined by f(z,α,β)=αz(1–z)β. where  and  are complex numbers, and β is a positive integers number, the visualization method used in this work to generate fractals of the map and to inspect the relation between the value of β and the shape of the map, this visualization analysis showed also that, as the value of β increasing, as the number of humps in the function also increasing, and it demonstrate that is true also for the function’s first iteration , f2(x0)=f(f(x0)) and the second iteration , f3(x0)=f(f2(x0)), beside that , the visualization technique showed that the number of humps in that fractal is less than the ones in the second iteration of the original function ,the study of the critical points and their properties of the logistic map also discussed it, whereas finding the fixed point led to find the critical point of the function f, in addition , it haven proven for the set of all pointsα∈C and β∈N, the iteration function f(f(z) has an attractive fixed points, and belongs to the region specified by the disc |1–β(α–1)|<1. Also, The discussion of the Mandelbrot set of the function defined by the f(f(z)) examined in complex plans using the path principle, such that the path of the critical point z=z0 is restricted, finally, it has proven that the Mandelbrot set f(z,α,β) contains all the attractive fixed points and all the complex numbers  in which α≤(1/β+1) (1/β+1) and the region containing the attractive fixed points for f2(z,α,β) was identified


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