31 August 2007 4:57:54.270 PM INT_EXACTNESS_LAGUERRE FORTRAN90 version Investigate the polynomial exactness of a Gauss-Laguerre quadrature rule by integrating exponentially weighted monomials up to a given degree over the [0,oo) interval. The rule may be defined on another interval, [A,oo) in which case it is adjusted to the [0,oo) interval. INT_EXACTNESS_LAGUERRE: User input: Quadrature rule X file = "lag_o16_x.txt". Quadrature rule W file = "lag_o16_w.txt". Quadrature rule R file = "lag_o16_r.txt". Maximum degree to check = 35 Spatial dimension = 1 Number of points = 16 The quadrature rule to be tested is a Gauss-Laguerre rule of ORDER = 16 with A = 0.00000 OPTION = 0, standard rule: Integral ( A <= x < oo ) exp(-x) f(x) dx is to be approximated by sum ( 1 <= I <= ORDER ) w(i) * f(x(i)). Weights W: w( 1) = 0.2061517149578010 w( 2) = 0.3310578549508841 w( 3) = 0.2657957776442142 w( 4) = 0.1362969342963776 w( 5) = 0.4732892869412523E-01 w( 6) = 0.1129990008033945E-01 w( 7) = 0.1849070943526311E-02 w( 8) = 0.2042719153082785E-03 w( 9) = 0.1484458687398130E-04 w(10) = 0.6828319330871197E-06 w(11) = 0.1881024841079673E-07 w(12) = 0.2862350242973883E-09 w(13) = 0.2127079033224104E-11 w(14) = 0.6297967002517869E-14 w(15) = 0.5050473700035514E-17 w(16) = 0.4161462370372855E-21 Abscissas X: x( 1) = 0.8764941047892787E-01 x( 2) = 0.4626963289150808 x( 3) = 1.141057774831227 x( 4) = 2.129283645098381 x( 5) = 3.437086633893207 x( 6) = 5.078018614549769 x( 7) = 7.070338535048235 x( 8) = 9.438314336391938 x( 9) = 12.21422336886616 x(10) = 15.44152736878162 x(11) = 19.18015685675314 x(12) = 23.51590569399191 x(13) = 28.57872974288214 x(14) = 34.58339870228664 x(15) = 41.94045264768835 x(16) = 51.70116033954334 Region R: r( 1) = 0.000000000000000 r( 2) = 0.1000000000000000E+31 A Gauss-Laguerre rule would be able to exactly integrate monomials up to and including degree = 31 Error Degree Exponents 0.0000000000000001 0 0 0.0000000000000002 1 1 0.0000000000000004 2 2 0.0000000000000002 3 3 0.0000000000000002 4 4 0.0000000000000007 5 5 0.0000000000000007 6 6 0.0000000000000004 7 7 0.0000000000000013 8 8 0.0000000000000011 9 9 0.0000000000000016 10 10 0.0000000000000022 11 11 0.0000000000000027 12 12 0.0000000000000031 13 13 0.0000000000000038 14 14 0.0000000000000040 15 15 0.0000000000000042 16 16 0.0000000000000047 17 17 0.0000000000000044 18 18 0.0000000000000047 19 19 0.0000000000000042 20 20 0.0000000000000040 21 21 0.0000000000000036 22 22 0.0000000000000033 23 23 0.0000000000000036 24 24 0.0000000000000036 25 25 0.0000000000000033 26 26 0.0000000000000036 27 27 0.0000000000000042 28 28 0.0000000000000049 29 29 0.0000000000000058 30 30 0.0000000000000064 31 31 0.0000000016636638 32 32 0.0000000274757702 33 33 0.0000002335930378 34 34 0.0000013619942516 35 35 INT_EXACTNESS_LAGUERRE: Normal end of execution. 31 August 2007 4:57:54.280 PM