0000000000052981

AUTHOR

Juan R. Torregrosa

0000-0002-9893-0761

showing 4 related works from this author

Avoiding strange attractors in efficient parametric families of iterative methods for solving nonlinear problems

2019

[EN] Searching zeros of nonlinear functions often employs iterative procedures. In this paper, we construct several families of iterative methods with memory from one without memory, that is, we have increased the order of convergence without adding new functional evaluations. The main aim of this manuscript yields in the advantage that the use of real multidimensional dynamics gives us to decide among the different classes designed and, afterwards, to select its most stable members. Moreover, we have found some elements of the family whose behavior includes strange attractors of different kinds that must be avoided in practice. In this sense, Feigenbaum diagrams have resulted an extremely …

Feigenbaum diagramsNumerical AnalysisMathematical optimizationRelation (database)Iterative methodApplied MathematicsNonlinear problems010103 numerical & computational mathematicsConstruct (python library)01 natural sciencesComputational efficiency010101 applied mathematicsComputational MathematicsNonlinear systemRate of convergenceAttractorIterative methods with and without memoryNumerical tests0101 mathematicsMATEMATICA APLICADAQualitative analysisMathematicsParametric statisticsApplied Numerical Mathematics
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Efficient High-Order Iterative Methods for Solving Nonlinear Systems and Their Application on Heat Conduction Problems

2017

[EN] For solving nonlinear systems of big size, such as those obtained by applying finite differences for approximating the solution of diffusion problem and heat conduction equations, three-step iterative methods with eighth-order local convergence are presented. The computational efficiency of the new methods is compared with those of some known ones, obtaining good conclusions, due to the particular structure of the iterative expression of the proposed methods. Numerical comparisons are made with the same existing methods, on standard nonlinear systems and a nonlinear one-dimensional heat conduction equation by transforming it in a nonlinear system by using finite differences. From these…

MultidisciplinaryArticle SubjectGeneral Computer ScienceIterative methodMathematical analysisFinite differenceRelaxation (iterative method)010103 numerical & computational mathematics02 engineering and technologyThermal conduction01 natural sciencesExpression (mathematics)lcsh:QA75.5-76.95Local convergenceNonlinear system0202 electrical engineering electronic engineering information engineering020201 artificial intelligence & image processingHeat equationlcsh:Electronic computers. Computer science0101 mathematicsMATEMATICA APLICADAMathematicsComplexity
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Efficiency and Stability of a Family of Iterative Schemes for Solving Nonlinear Equations

2019

In this paper, we construct a family of iterative methods with memory from one without memory, analyzing their convergence and stability. The main aim of this manuscript yields in the advantage that the use of real multidimensional dynamics gives us to decide among the different classes designed and, afterwards, to select its most stable members. Some numerical tests confirm the theoretical results.

Nonlinear systemComputer scienceIterative methodConvergence (routing)Stability (learning theory)Applied mathematicsConstruct (python library)Numerical tests
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P-matrix completions under weak symmetry assumptions

2000

An n-by-n matrix is called a Π-matrix if it is one of (weakly) sign-symmetric, positive, nonnegative P-matrix, (weakly) sign-symmetric, positive, nonnegative P0,1-matrix, or Fischer, or Koteljanskii matrix. In this paper, we are interested in Π-matrix completion problems, that is, when a partial Π-matrix has a Π-matrix completion. Here, we prove that a combinatorially symmetric partial positive P-matrix has a positive P-matrix completion if the graph of its specified entries is an n-cycle. In general, a combinatorially symmetric partial Π-matrix has a Π-matrix completion if the graph of its specified entries is a 1-chordal graph. This condition is also necessary for (weakly) sign-symmetric …

Discrete mathematicsMatrix completionNumerical AnalysisAlgebra and Number TheorySymmetric graphCombinatorial symmetry010102 general mathematicsComparability graphIncidence matrix010103 numerical & computational mathematics01 natural sciencesGraphCombinatoricsVertex-transitive graphP-matrixGraph powerDiscrete Mathematics and CombinatoricsRegular graphAdjacency matrixGeometry and Topology0101 mathematicsComplement graphMathematicsLinear Algebra and its Applications
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