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// Copyright 2018 Hans Dembinski
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt
// or copy at http://www.boost.org/LICENSE_1_0.txt)
//[ guide_custom_2d_axis
#include <boost/histogram.hpp>
#include <cassert>
int main() {
using namespace boost::histogram;
// axis which returns 1 if the input falls inside the unit circle and zero otherwise
struct circle_axis {
// accepts a 2D point in form of a std::tuple
axis::index_type index(const std::tuple<double, double>& point) const {
const auto x = std::get<0>(point);
const auto y = std::get<1>(point);
return x * x + y * y <= 1.0;
}
axis::index_type size() const { return 2; }
};
auto h1 = make_histogram(circle_axis());
// fill looks normal for a histogram which has only one Nd-axis
h1(0, 0); // in
h1(0, -1); // in
h1(0, 1); // in
h1(-1, 0); // in
h1(1, 0); // in
h1(1, 1); // out
h1(-1, -1); // out
// 2D histogram, but only 1D index
assert(h1.at(0) == 2); // out
assert(h1.at(1) == 5); // in
// other axes can be combined with a Nd-axis
auto h2 = make_histogram(circle_axis(), axis::category<std::string>({"red", "blue"}));
// now we need to pass arguments for Nd-axis explicitly as std::tuple
h2(std::make_tuple(0, 0), "red");
h2(std::make_tuple(1, 1), "blue");
// 3D histogram, but only 2D index
assert(h2.at(0, 0) == 0); // out, red
assert(h2.at(0, 1) == 1); // out, blue
assert(h2.at(1, 0) == 1); // in, red
assert(h2.at(1, 1) == 0); // in, blue
}
//]
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