sphere_lebedev_rule, a FORTRAN90 code which computes a Lebedev quadrature rule for approximating integrals 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:
Of course, each pair of values (thetai, phii) has a corresponding Cartesian representation:
xi = cos ( thetai ) * sin ( phii )which may be more useful when evaluating integrands.
yi = sin ( thetai ) * sin ( phii )
zi = cos ( phii )
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)
The computer code and data files described and made available on this web page are distributed under the MIT license
sphere_lebedev_rule is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version.
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SPHERE_LEBEDEV_RULE, a dataset directory which contains sets of points on a sphere which can be used for quadrature rules of a known precision;
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WEDGE_FELIPPA_RULE, a FORTRAN90 code which returns quadratures rules for approximating integrals over the interior of the unit wedge in 3D.