function fx = p43_fun ( n, x ) %*****************************************************************************80 % %% P43_FUN evaluates the integrand for problem 43. % % Discussion: % % The problem has a parameter ALPHA that can be set by calling % P43_PARAM_SET. % % The suggested parameter range is 0.1 <= ALPHA <= 2.0. % % The integrand has an algebraic endpoint singularity at X = 1 % times a singular factor. % % Interval: % % 0 <= x <= 1 % % Integrand: % % ( ln ( 1 / x ) )^( alpha - 1 ) % % Exact Integral: % % Gamma(alpha) % % Licensing: % % This code is distributed under the GNU LGPL license. % % Modified: % % 12 November 2009 % % Author: % % John Burkardt % % Reference: % % Robert Piessens, Elise de Doncker-Kapenga, % Christian Ueberhuber, David Kahaner, % QUADPACK: A Subroutine Package for Automatic Integration, % Springer, 1983, page 84. % % Parameters: % % Input, integer N, the number of evaluation points. % % Input, real X(N), the evaluation points. % % Output, real FX(N), the integrand values. % alpha = p43_param_get ( ); fx(1:n) = ( log ( 1.0 ./ x(1:n) ) ).^( alpha - 1.0 ); i = find ( x == 0.0 | x == 1.0 ); fx(i) = 0.0; return end