sphere_lebedev_rule
    
    
    
      sphere_lebedev_rule,
      a C++ code which
      computes Lebedev quadrature rules 
      over the surface of the unit sphere in 3D.
    
    
      Vyacheslav Lebedev determined a family of 65 quadrature rules for the
      unit sphere, increasing in precision from 3 to 131, by 2 each time.
      This software library computes any one of a subset of 32 of these rules.
    
    
      Each rule is defined as a list of N values of theta, 
      phi, and w.
      Here:
      
        - 
          theta is a longitudinal angle, measured in degrees,
          and ranging from -180 to +180.
        
 
        - 
          phi is a latitudinal angle, measured in degrees,
          and ranging from 0 to 180.
        
 
        - 
          w is a weight.
        
 
      
    
    
      Of course, each pair of values 
      (thetai, phii) has a corresponding 
      Cartesian representation:
      
        xi = cos ( thetai ) * sin ( phii )
        yi = sin ( thetai ) * sin ( phii )
        zi = cos ( phii )
      
      which may be more useful when evaluating integrands.
    
    
      The integral of a function f(x,y,z) over the surface of the
      unit sphere can be approximated by
      
        integral f(x,y,z) = 4 * pi * sum ( 1 <= i <= N ) 
          f(xi,yi,zi)
      
    
    
      Licensing:
    
 
    
      The information on this web page is distributed under the MIT license.
    
    
      Languages:
    
    
      sphere_lebedev_rule is available in
      a C version and
      a C++ version and
      a Fortran90 version and
      a MATLAB version and
      an Octave version.
    
    
      Related Programs:
    
    
      
      sphere_lebedev_rule_test
    
    
      
      cpp_rule,
      a C++ code which
      computes a quadrature rule which
      estimates the integral of a function f(x), which might be defined over 
      a one dimensional region (a line) or more complex shapes such as 
      a circle, a triangle, a quadrilateral, a polygon, or a higher dimensional
      region, and which might include an associated weight function w(x).
    
    
      Reference:
    
    
      
        - 
          Axel Becke,
          A multicenter numerical integration scheme for polyatomic molecules,
          Journal of Chemical Physics,
          Volume 88, Number 4, 15 February 1988, pages 2547-2553.
         
        - 
          Vyacheslav Lebedev, Dmitri Laikov,
          A quadrature formula for the sphere of the 131st
          algebraic order of accuracy,
          Russian Academy of Sciences Doklady Mathematics,
          Volume 59, Number 3, 1999, pages 477-481.
         
        - 
          Vyacheslav Lebedev,
          A quadrature formula for the sphere of 59th algebraic
          order of accuracy,
          Russian Academy of Sciences Doklady Mathematics, 
          Volume 50, 1995, pages 283-286. 
         
        - 
          Vyacheslav Lebedev, A.L. Skorokhodov,
          Quadrature formulas of orders 41, 47, and 53 for the sphere,
          Russian Academy of Sciences Doklady Mathematics, 
          Volume 45, 1992, pages 587-592. 
         
        - 
          Vyacheslav Lebedev,
          Spherical quadrature formulas exact to orders 25-29,
          Siberian Mathematical Journal, 
          Volume 18, 1977, pages 99-107. 
         
        - 
          Vyacheslav Lebedev,
          Quadratures on a sphere,
          Computational Mathematics and Mathematical Physics, 
          Volume 16, 1976, pages 10-24. 
         
        - 
          Vyacheslav Lebedev,
          Values of the nodes and weights of ninth to seventeenth 
          order Gauss-Markov quadrature formulae invariant under the
          octahedron group with inversion,
          Computational Mathematics and Mathematical Physics,
          Volume 15, 1975, pages 44-51.
         
      
    
    
      Source Code:
    
    
      
    
    
    
      Last revised on 17 April 2020.