/usr/share/doc/ruby-gsl/examples/integration/qng.rb is in ruby-gsl 2.1.0.3+dfsg1-1build1.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | #!/usr/bin/env ruby
require("gsl")
include GSL
include Math
f = Function.alloc { |x| Math::sin(x)/x }
p f.qng(0, 2.0*Math::PI)
# Singular at x = 0
f2 = Function.alloc { |x| exp(-x)/sqrt(x) }
# This will fail...
#p f2.qng(0, 1)
p Integration.qng(f, [0, 2*Math::PI])
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