circle_rule, a C code which computes quadrature rules for the unit circle in 2D, that is, the circumference of the circle of radius 1 and center (0,0).
The user specifies the value NT, the number of equally spaced angles. The program returns vectors T(1:NT) and W(1:NT), which define the rule Q(f).
Given NT and the vectors T and W, the integral I(f) of a function f(x,y) is estimated by Q(f) as follows:
q = 0.0
for i = 1, nt
x = cos ( t(i) )
y = sin ( t(i) )
q = q + w(j) * f ( x, y )
end
The computer code and data files described and made available on this web page are distributed under the MIT license
circle_rule is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version.
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