1 September 2007 7:21:02.648 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_o4_modified_x.txt". Quadrature rule W file = "lag_o4_modified_w.txt". Quadrature rule R file = "lag_o4_modified_r.txt". Maximum degree to check = 10 Spatial dimension = 1 Number of points = 4 The quadrature rule to be tested is a Gauss-Laguerre rule of ORDER = 4 with A = 0.00000 OPTION = 1, modified rule: Integral ( A <= x < oo ) f(x) dx is to be approximated by sum ( 1 <= I <= ORDER ) w(i) * f(x(i)). Weights W: w( 1) = 0.8327391238378899 w( 2) = 2.048102438454297 w( 3) = 3.631146305821518 w( 4) = 6.487145084407663 Abscissas X: x( 1) = 0.3225476896193923 x( 2) = 1.745761101158346 x( 3) = 4.536620296921128 x( 4) = 9.395070912301131 Region R: r( 1) = 0.000000000000000 r( 2) = 0.1797693134862000 A Gauss-Laguerre rule would be able to exactly integrate monomials up to and including degree = 7 Error Degree Exponents 0.0000000000000007 0 0 0.0000000000000002 1 1 0.0000000000000002 2 2 0.0000000000000002 3 3 0.0000000000000002 4 4 0.0000000000000004 5 5 0.0000000000000002 6 6 0.0000000000000004 7 7 0.0142857142857139 8 8 0.0650793650793650 9 9 0.1641269841269841 10 10 INT_EXACTNESS_LAGUERRE: Normal end of execution. 1 September 2007 7:21:02.672 PM