02 March 2008 05:00:24 PM INT_EXACTNESS_CHEBYSHEV1 C++ version Investigate the polynomial exactness of a Gauss-Chebyshev type 1 quadrature rule by integrating weighted monomials up to a given degree over the [-1,+1] interval. INT_EXACTNESS_CHEBYSHEV1: User input: Quadrature rule X file = "cheby1_o16_x.txt". Quadrature rule W file = "cheby1_o16_w.txt". Quadrature rule R file = "cheby1_o16_r.txt". Maximum degree to check = 35 Spatial dimension = 1 Number of points = 16 The quadrature rule to be tested is a Gauss-Legendre rule ORDER = 16 Standard rule: Integral ( -1 <= x <= +1 ) f(x) dx is to be approximated by sum ( 1 <= I <= ORDER ) w(i) * f(x(i)). Weights W: w[ 0] = 0.1963495408493621 w[ 1] = 0.1963495408493621 w[ 2] = 0.1963495408493621 w[ 3] = 0.1963495408493621 w[ 4] = 0.1963495408493621 w[ 5] = 0.1963495408493621 w[ 6] = 0.1963495408493621 w[ 7] = 0.1963495408493621 w[ 8] = 0.1963495408493621 w[ 9] = 0.1963495408493621 w[10] = 0.1963495408493621 w[11] = 0.1963495408493621 w[12] = 0.1963495408493621 w[13] = 0.1963495408493621 w[14] = 0.1963495408493621 w[15] = 0.1963495408493621 Abscissas X: x[ 0] = -0.9951847266721968 x[ 1] = -0.9569403357322088 x[ 2] = -0.8819212643483549 x[ 3] = -0.773010453362737 x[ 4] = -0.6343932841636454 x[ 5] = -0.4713967368259977 x[ 6] = -0.2902846772544622 x[ 7] = -0.09801714032956065 x[ 8] = 0.09801714032956076 x[ 9] = 0.2902846772544623 x[10] = 0.4713967368259978 x[11] = 0.6343932841636455 x[12] = 0.773010453362737 x[13] = 0.881921264348355 x[14] = 0.9569403357322088 x[15] = 0.9951847266721968 Region R: r[ 0] = -1 r[ 1] = 1 A Gauss-Chebyshev type 1 rule would be able to exactly integrate monomials up to and including degree = 31 Error Degree 4.240739575284689e-16 0 8.326672684688674e-17 1 0 2 8.326672684688674e-17 3 0 4 2.775557561562891e-17 5 2.261727773485168e-16 6 1.387778780781446e-16 7 1.292415870562953e-16 8 2.775557561562891e-17 9 1.436017633958837e-16 10 1.110223024625157e-16 11 1.566564691591458e-16 12 0 13 3.374139335735448e-16 14 5.551115123125783e-17 15 3.599081958117811e-16 16 5.551115123125783e-17 17 7.621585323073012e-16 18 0 19 8.022721392708434e-16 20 2.775557561562891e-17 21 6.303566808556627e-16 22 0 23 1.315526986133557e-15 24 2.775557561562891e-17 25 9.120987103859327e-16 26 2.775557561562891e-17 27 1.064115162116922e-15 28 0 29 1.223120875996462e-15 30 0 31 3.3273433102101e-09 32 0 33 2.913945057385399e-08 34 2.775557561562891e-17 35 INT_EXACTNESS_CHEBYSHEV1: Normal end of execution. 02 March 2008 05:00:24 PM