ceph/src/boost/libs/histogram/examples/guide_axis_circular.cpp

   1 // Copyright 2019 Hans Dembinski
   2 //
   3 // Distributed under the Boost Software License, Version 1.0.
   4 // (See accompanying file LICENSE_1_0.txt
   5 // or copy at http://www.boost.org/LICENSE_1_0.txt)
   6
   7 //[ guide_axis_circular
   8
   9 #include <boost/histogram/axis.hpp>
  10 #include <limits>
  11
  12 int main() {
  13   using namespace boost::histogram;
  14
  15   // make a circular regular axis ... [0, 180), [180, 360), [0, 180) ....
  16   using opts = decltype(axis::option::overflow | axis::option::circular);
  17   auto r = axis::regular<double, use_default, use_default, opts>{2, 0., 360.};
  18   assert(r.index(-180) == 1);
  19   assert(r.index(0) == 0);
  20   assert(r.index(180) == 1);
  21   assert(r.index(360) == 0);
  22   assert(r.index(540) == 1);
  23   assert(r.index(720) == 0);
  24   // special values are mapped to the overflow bin index
  25   assert(r.index(std::numeric_limits<double>::infinity()) == 2);
  26   assert(r.index(-std::numeric_limits<double>::infinity()) == 2);
  27   assert(r.index(std::numeric_limits<double>::quiet_NaN()) == 2);
  28
  29   // since the regular axis is the most common circular axis, there exists an alias
  30   auto c = axis::circular<>{2, 0., 360.};
  31   assert(r == c);
  32
  33   // make a circular integer axis
  34   auto i = axis::integer<int, use_default, axis::option::circular_t>{1, 4};
  35   assert(i.index(0) == 2);
  36   assert(i.index(1) == 0);
  37   assert(i.index(2) == 1);
  38   assert(i.index(3) == 2);
  39   assert(i.index(4) == 0);
  40   assert(i.index(5) == 1);
  41 }
  42
  43 //]