/usr/share/doc/ruby-gsl/examples/integration/qags.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 | #!/usr/bin/env ruby
require("gsl")
include GSL
# Singular at x = 0
f = Function.alloc { |x| 1.0/Math::sqrt(x) }
puts("QAGS")
p f.qags(0, 1)
p f.qags([0, 1])
p Integration.qags(f, 0, 1)
p Integration.qags(f, [0, 1])
|