25 February 2008 12:13:29.237 PM INT_EXACTNESS_GEGENBAUER FORTRAN90 version Investigate the polynomial exactness of a Gauss-Gegenbauer quadrature rule by integrating weighted monomials up to a given degree over the [-1,+1] interval. INT_EXACTNESS_GEGENBAUER: User input: Quadrature rule X file = "gegen_o16_a0.5_x.txt". Quadrature rule W file = "gegen_o16_a0.5_w.txt". Quadrature rule R file = "gegen_o16_a0.5_r.txt". Maximum degree to check = 35 Exponent of (1-x^2), ALPHA = 0.500000 Spatial dimension = 1 Number of points = 16 The quadrature rule to be tested is a Gauss-Gegenbauer rule ORDER = 16 ALPHA = 0.500000 Standard rule: Integral ( -1 <= x <= +1 ) (1-x^2)^alpha f(x) dx is to be approximated by sum ( 1 <= I <= ORDER ) w(i) * f(x(i)). Weights W: w( 1) = 0.6239551412252181E-02 w( 2) = 0.2411551965623589E-01 w( 3) = 0.5121365616644176E-01 w( 4) = 0.8387420745120895E-01 w( 5) = 0.1176861850811666 w( 6) = 0.1480830941187536 w( 7) = 0.1709596635633561 w( 8) = 0.1832262859480332 w( 9) = 0.1832262859480331 w(10) = 0.1709596635633561 w(11) = 0.1480830941187535 w(12) = 0.1176861850811666 w(13) = 0.8387420745120895E-01 w(14) = 0.5121365616644213E-01 w(15) = 0.2411551965623589E-01 w(16) = 0.6239551412252181E-02 Abscissas X: x( 1) = -0.9829730996839018 x( 2) = -0.9324722294043558 x( 3) = -0.8502171357296141 x( 4) = -0.7390089172206591 x( 5) = -0.6026346363792564 x( 6) = -0.4457383557765383 x( 7) = -0.2736629900720829 x( 8) = -0.9226835946330200E-01 x( 9) = 0.9226835946330200E-01 x(10) = 0.2736629900720829 x(11) = 0.4457383557765383 x(12) = 0.6026346363792564 x(13) = 0.7390089172206591 x(14) = 0.8502171357296141 x(15) = 0.9324722294043558 x(16) = 0.9829730996839018 Region R: r( 1) = -1.0000000000000000 r( 2) = 1.0000000000000000 A Gauss-Gegenbauer rule would be able to exactly integrate monomials up to and including degree = 31 Error Degree Exponents 0.0000000000000008 0 0 0.0000000000000002 1 1 0.0000000000000001 2 2 0.0000000000000002 3 3 0.0000000000000006 4 4 0.0000000000000002 5 5 0.0000000000000005 6 6 0.0000000000000001 7 7 0.0000000000000002 8 8 0.0000000000000001 9 9 0.0000000000000024 10 10 0.0000000000000001 11 11 0.0000000000000096 12 12 0.0000000000000000 13 13 0.0000000000000015 14 14 0.0000000000000000 15 15 0.0000000000000049 16 16 0.0000000000000000 17 17 0.0000000000000008 18 18 0.0000000000000000 19 19 0.0000000000000046 20 20 0.0000000000000000 21 21 0.0000000000000069 22 22 0.0000000000000000 23 23 0.0000000000000032 24 24 0.0000000000000000 25 25 0.0000000000000014 26 26 0.0000000000000000 27 27 0.0000000000000044 28 28 0.0000000000000000 29 29 0.0000000000000083 30 30 0.0000000000000000 31 31 0.0000000282823902 32 32 0.0000000000000000 33 33 0.0000002468282487 34 34 0.0000000000000000 35 35 INT_EXACTNESS_GEGENBAUER: Normal end of execution. 25 February 2008 12:13:29.247 PM