scholarly journals Winding Numbers, Unwinding Numbers, and the Lambert W Function

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.

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.


2001 ◽  
Vol 25 (7) ◽  
pp. 429-450 ◽  
Author(s):  
Silviu Olariu

Two distinct systems of commutative complex numbers inndimensions are described, of polar and planar types. Exponential forms ofn-complex numbers are given in each case, which depend on geometric variables. Azimuthal angles, which are cyclic variables, appear in these forms at the exponent, and this leads to the concept of residue for path integrals ofn-complex functions. The exponential function of ann-complex number is expanded in terms of functions called in this paper cosexponential functions, which are generalizations tondimensions of the circular and hyperbolic sine and cosine functions. The factorization ofn-complex polynomials is discussed.


Author(s):  
Arthur Benjamin ◽  
Gary Chartrand ◽  
Ping Zhang

This chapter considers Hamiltonian graphs, a class of graphs named for nineteenth-century physicist and mathematician Sir William Rowan Hamilton. In 1835 Hamilton discovered that complex numbers could be represented as ordered pairs of real numbers. That is, a complex number a + b i (where a and b are real numbers) could be treated as the ordered pair (a, b). Here the number i has the property that i² = -1. Consequently, while the equation x² = -1 has no real number solutions, this equation has two solutions that are complex numbers, namely i and -i. The chapter first examines Hamilton's icosian calculus and Icosian Game, which has a version called Traveller's Dodecahedron or Voyage Round the World, before concluding with an analysis of the Knight's Tour Puzzle, the conditions that make a given graph Hamiltonian, and the Traveling Salesman Problem.


2019 ◽  
Vol 300 ◽  
pp. 15001
Author(s):  
Tadeusz Łagoda ◽  
Marta Kurek ◽  
Karolina Łagoda

This criterion has been repeatedly verified, analyzed and special cases of this criterion reducing complex stress to equivalent uniaxial were taken into account. Since both normal and shear stress are vectors, we encounter the mathematical problem of adding these vectors, and the question arises how to understand the obtained equivalent stress, because two perpendicular vectors are added with weighting factors. Therefore, in this work it was proposed to adopt a system of complex numbers. Normal stress was defined as the real part and shear stress as imaginary part. As a result, on the basis of the defined complex number and basing on pure bending and pure torsion after transformations, the expression for equivalent stress was identical to the previously proposed criteria defined on the basis of the concept of prof. Macha.


2018 ◽  
Vol 7 (2.24) ◽  
pp. 336
Author(s):  
N Saraswathi ◽  
Lokesh Modi ◽  
Aatish Nair

Complex numbers multiplication is a fundamental mathematical process in systems like digital signal processors (DSP). The main     objective of complex number multiplication is to perform operations at lightning fast speed with less intake of power. In this paper, the best possible architecture is designed for a Real vedic multiplier based on the ancient Indian mathematical procedure known as URDHVA TIRYAKBHYAM SUTRA i.e. the structure of a MxM Vedic real multiplier architecture is developed. Then, a Vedic real multiplier solution of a complex multiplier is presented and its simulation results are obtained. The MxM Vedic real multiplier architecture, architecture of the Real Vedic  multiplier solution for 32 x 32 bit complex numbers multiplication of complex multiplier and the architecture of a FIR filter has been code in Verilog and implementation is done through Modelsim 5.6 and Xilinx ISE 7.1 navigator. 


Symmetry ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 877
Author(s):  
Wolf-Dieter Richter

Dispensing with the common property of distributivity and replacing classical trigonometric functions with their l p -counterparts in Euler’s trigonometric representation of complex numbers, classes of l p -complex numbers are introduced and some of their basic properties are proved. The collection of all points that leave the l p -absolute value of each l p -complex number invariant under l p -complex numbers multiplication is shown to be a group of elements that have l p -absolute value one but not the symmetry group.


1993 ◽  
Vol 2 (3) ◽  
pp. 77-106 ◽  
Author(s):  
Harry H. Cheng

The handling of complex numbers in the CHprogramming language will be described in this paper. Complex is a built-in data type in CH. The I/O, arithmetic and relational operations, and built-in mathematical functions are defined for both regular complex numbers and complex metanumbers of ComplexZero, Complexlnf, and ComplexNaN. Due to polymorphism, the syntax of complex arithmetic and relational operations and built-in mathematical functions are the same as those for real numbers. Besides polymorphism, the built-in mathematical functions are implemented with a variable number of arguments that greatly simplify computations of different branches of multiple-valued complex functions. The valid lvalues related to complex numbers are defined. Rationales for the design of complex features in CHare discussed from language design, implementation, and application points of views. Sample CHprograms show that a computer language that does not distinguish the sign of zeros in complex numbers can also handle the branch cuts of multiple-valued complex functions effectively so long as it is appropriately designed and implemented.


2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Rafael G. Campos ◽  
Marisol L. Calderón

We find approximate expressionsx̃(k,n,a)andỹ(k,n,a)for the real and imaginary parts of thekth zerozk=xk+iykof the Bessel polynomialyn(x;a). To obtain these closed-form formulas we use the fact that the points of well-defined curves in the complex plane are limit points of the zeros of the normalized Bessel polynomials. Thus, these zeros are first computed numerically through an implementation of the electrostatic interpretation formulas and then, a fit to the real and imaginary parts as functions ofk,nandais obtained. It is shown that the resulting complex numberx̃(k,n,a)+iỹ(k,n,a)isO(1/n2)-convergent tozkfor fixedk.


Author(s):  
K. Sugihara

This study is focused on a proposed alternative algorithm for Google's PageRank, named Hermitian centrality score, which employs complex numbers for scoring a node of the network to overcome the issues of PageRank’s link analysis. This study presents the Hermitian centrality score as a solution for the problems of PageRank, which are associated with the damping factor of Google’s algorithm. The algorithm for Hermitian centrality score is designed to be free from a damping factor, and it reproduces PageRank results well. Moreover, the proposed algorithm can mathematically and systematically change the point of a node of a network.


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