Header menu link for other important links
Numerical integration using hybrid of block-pulse functions and lagrange polynomial
G. Uma, , S. Hariharan
Published in Academic Press
Volume: 106
Issue: 5
Pages: 33 - 44
This paper attempts to solve the definite integrals numerically using Gaussian quadrature rule with variable spacing. In this paper, the orthogonal polynomial is chosen to be the hybrid function formed from the block-pulse function of order N and Lagrange basis polynomial of order M. Here, the domain of the integral is partitioned into N sub-intervals, and the M roots of the Legendre polynomial of order M, are chosen as the nodes in each sub-interval. Having identified M nodes in each sub-interval, the Lagrange polynomial basis of order M is constructed. The total number of abscissas (or quadrature points) in the domain of the definite integral is NM. The weights can be easily obtained from the Lagrange polynomial. A significant advantage of this method is that the Hybrid matrix turns out to be an Identity matrix of order NM and the hybrid coefficients are simply the value of the integrand at the nodal points. The method is explained for single definite integrals, and this rule is extended to cover definite double and triple integrals with constant or variable limits. A comparative study of this method for both definite single and double integrals with Haar Wavelet and Hybrid function [2] reveals that better accuracy can be achieved with this quadrature rule with less number of points. It can be considered to cover a broad class of integrands. © 2016 Academic Publications, Ltd.
About the journal
JournalInternational Journal of Pure and Applied Mathematics
PublisherAcademic Press