/usr/share/doc/ruby-gsl/examples/monte/vegas.rb is in ruby-gsl 2.1.0.3+dfsg1-1build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 | #!/usr/bin/env ruby
require("gsl")
include GSL
include Monte
include Math
proc_f = Proc.new { |k, dim, params|
pi = Math::PI
a = 1.0/(pi*pi*pi)
a/(1.0 - cos(k[0])*cos(k[1])*cos(k[2]))
}
def display_results(title, result, error)
exact = 1.3932039296856768591842462603255
diff = result - exact
printf("%s ==================\n", title);
printf("result = % .6f\n", result);
printf("sigma = % .6f\n", error);
printf("exact = % .6f\n", exact);
printf("error = % .6f = %.1g sigma\n", diff, diff.abs/error)
end
dim = 3
xl = Vector.alloc([0, 0, 0])
xu = Vector.alloc([PI, PI, PI])
G = Monte::Function.alloc(proc_f, dim)
calls = 10000
r = GSL::Rng.alloc(Rng::DEFAULT)
vegas = Monte::Vegas.alloc(dim)
result, error = Monte::Vegas::integrate(G, xl, xu, dim, calls, r, vegas)
#result, error = Monte::Vegas::integrate(G, xl, xu, calls, r, vegas)
#result, error = Monte::Vegas::integrate(G, xl, xu, calls, vegas)
#result, error = Monte::Vegas::integrate(G, xl, xu, dim, calls, r, "vegas")
#result, error = G.integrate(xl, xu, dim, calls, r, vegas)
#result, error = G.integrate(xl, xu, calls, r, vegas)
#result, error = G.integrate(xl, xu, calls, vegas)
#result, error = vegas.integrate(G, xl, xu, dim, calls, r)
#result, error = vegas.integrate(G, xl, xu, calls, r)
#result, error = vegas.integrate(G, xl, xu, dim, calls)
#result, error = vegas.integrate(G, xl, xu, calls)
display_results("vegas", result, error)
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