07-Jan-2022 22:44:17 laguerre_exactness_test(): MATLAB/Octave version 9.8.0.1380330 (R2020a) Update 2 Test laguerre_exactness(). 07-Jan-2022 22:44:17 LAGUERRE_EXACTNESS MATLAB version Investigate the exactness of a Gauss-Laguerre quadrature rule for integrating monomials with density exp(-x) or density 1 over the [0,+oo) interval. LAGUERRE_EXACTNESS: User input: Quadrature rule X file = "lag_o04_x.txt". Quadrature rule W file = "lag_o04_w.txt". Quadrature rule R file = "lag_o04_r.txt". Maximum degree to check = 8 OPTION = 0, integrate exp(-x)*f(x). Spatial dimension = 1 Number of points = 4 The quadrature rule to be tested is a Gauss-Laguerre quadrature rule of ORDER = 4 for integrals of the type: Integral ( 0 <= x < +oo ) f(x) exp(-x) dx Weights W: w(1) = 0.6031541043416337 w(2) = 0.3574186924377999 w(3) = 0.0388879085150054 w(4) = 0.0005392947055613 Abscissas X: x(1) = 0.3225476896193923 x(2) = 1.7457611011583460 x(3) = 4.5366202969211278 x(4) = 9.3950709123011364 Region R: r(1) = 0.000000e+00 r(2) = 1.000000e+30 A Gauss-Laguerre rule would be able to exactly integrate monomials up to and including degree = 7 Degree Error 0 0.0000000000000004 1 0.0000000000000000 2 0.0000000000000000 3 0.0000000000000001 4 0.0000000000000000 5 0.0000000000000005 6 0.0000000000000013 7 0.0000000000000022 8 0.0142857142857116 LAGUERRE_EXACTNESS: Normal end of execution. 07-Jan-2022 22:44:17 laguerre_exactness_test(): Normal end of execution. 07-Jan-2022 22:44:17