Advances in the Approximation of the Matrix Hyperbolic Tangent

[EN] In this paper, we introduce two approaches to compute the matrix hyperbolic tangent. While one of them is based on its own definition and uses the matrix exponential, the other one is focused on the expansion of its Taylor series. For this second approximation, we analyse two different alternat...

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Detalles Bibliográficos
Autores: Ibáñez González, Jacinto Javier|||0000-0002-6912-4453, Alonso Abalos, José Miguel|||0000-0001-6812-7364, Sastre, Jorge|||0000-0002-8612-6717, Defez Candel, Emilio|||0000-0002-3303-6371, Alonso-Jordá, Pedro|||0000-0002-6882-6592
Tipo de recurso: artículo
Fecha de publicación:2021
País:España
Institución:Universitat Politècnica de València (UPV)
Repositorio:RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia
Idioma:inglés
OAI Identifier:oai:riunet.upv.es:10251/186472
Acceso en línea:https://riunet.upv.es/handle/10251/186472
Access Level:acceso abierto
Palabra clave:Matrix functions
Matrix hyperbolic tangent
Matrix exponential
Taylor series
Matrix polynomial evaluation
MATEMATICA APLICADA
TEORIA DE LA SEÑAL Y COMUNICACIONES
CIENCIAS DE LA COMPUTACION E INTELIGENCIA ARTIFICIAL
Descripción
Sumario:[EN] In this paper, we introduce two approaches to compute the matrix hyperbolic tangent. While one of them is based on its own definition and uses the matrix exponential, the other one is focused on the expansion of its Taylor series. For this second approximation, we analyse two different alternatives to evaluate the corresponding matrix polynomials. This resulted in three stable and accurate codes, which we implemented in MATLAB and numerically and computationally compared by means of a battery of tests composed of distinct state-of-the-art matrices. Our results show that the Taylor series-based methods were more accurate, although somewhat more computationally expensive, compared with the approach based on the exponential matrix. To avoid this drawback, we propose the use of a set of formulas that allows us to evaluate polynomials in a more efficient way compared with that of the traditional Paterson¿Stockmeyer method, thus, substantially reducing the number of matrix products (practically equal in number to the approach based on the matrix exponential), without penalising the accuracy of the result