function [ o, x, w ] = en_r2_01_1 ( n ) %*****************************************************************************80 % %% EN_R2_01_1 implements the Stroud rule 1.1 for region EN_R2. % % Discussion: % % The rule has order O = 1. % % The rule has precision P = 1. % % EN_R2 is the entire N-dimensional space with weight function % % w(x) = exp ( - x1^2 - x2^2 ... - xn^2 ) % % Licensing: % % This code is distributed under the GNU LGPL license. % % Modified: % % 20 January 2010 % % Author: % % John Burkardt % % Reference: % % Arthur Stroud, % Approximate Calculation of Multiple Integrals, % Prentice Hall, 1971, % ISBN: 0130438936, % LC: QA311.S85. % % Parameters: % % Input, integer N, the spatial dimension. % % Output, integer O, the order. % % Output, real X(N,O), the abscissas. % % Output, real W(O), the weights. % o = 1; volume = sqrt ( pi^n ); x = zeros ( n, o ); w = zeros ( o, 1 ); k = 0; % % 1 point. % k = k + 1; % x(1:n,k) = 0.0; w(k) = volume; return end