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// 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_axis_basic_demo

#include <boost/histogram/axis.hpp>

#include <limits>

int main() {

using namespace boost::histogram;

// make a regular axis with 10 bins over interval from 1.5 to 2.5

auto r = axis::regular<>{10, 1.5, 2.5};

// `<>` is needed in C++14 because the axis is templated,

// in C++17 you can do: auto r = axis::regular{10, 1.5, 2.5};

assert(r.size() == 10);

// alternatively, you can define the step size with the `step` marker

auto r_step = axis::regular<>{axis::step(0.1), 1.5, 2.5};

assert(r_step == r);

// histogram uses the `index` method to convert values to indices

// note: intervals of builtin axis types are always semi-open [a, b)

assert(r.index(1.5) == 0);

assert(r.index(1.6) == 1);

assert(r.index(2.4) == 9);

// index for a value below the start of the axis is always -1

assert(r.index(1.0) == -1);

assert(r.index(-std::numeric_limits<double>::infinity()) == -1);

// index for a value below the above the end of the axis is always `size()`

assert(r.index(3.0) == 10);

assert(r.index(std::numeric_limits<double>::infinity()) == 10);

// index for not-a-number is also `size()` by convention

assert(r.index(std::numeric_limits<double>::quiet_NaN()) == 10);

// make a variable axis with 3 bins [-1.5, 0.1), [0.1, 0.3), [0.3, 10)

auto v = axis::variable<>{-1.5, 0.1, 0.3, 10.};

assert(v.index(-2.0) == -1);

assert(v.index(-1.5) == 0);

assert(v.index(0.1) == 1);

assert(v.index(0.3) == 2);

assert(v.index(10) == 3);

assert(v.index(20) == 3);

// make an integer axis with 3 bins at -1, 0, 1

auto i = axis::integer<>{-1, 2};

assert(i.index(-2) == -1);

assert(i.index(-1) == 0);

assert(i.index(0) == 1);

assert(i.index(1) == 2);

assert(i.index(2) == 3);

// make an integer axis called "foo"

auto i_with_label = axis::integer<>{-1, 2, "foo"};

// all builtin axis types allow you to pass some optional metadata as the last

// argument in the constructor; a string by default, but can be any copyable type

// two axis do not compare equal if they differ in their metadata

assert(i != i_with_label);

// integer axis also work well with unscoped enums

enum { red, blue };

auto i_for_enum = axis::integer<>{red, blue + 1};

assert(i_for_enum.index(red) == 0);

assert(i_for_enum.index(blue) == 1);

// make a category axis from a scoped enum and/or if the identifiers are not consecutive

enum class Bar { red = 12, blue = 6 };

auto c = axis::category<Bar>{Bar::red, Bar::blue};

assert(c.index(Bar::red) == 0);

assert(c.index(Bar::blue) == 1);

// c.index(12) is a compile-time error, since the argument must be of type `Bar`

// category axis can be created for any copyable and equal-comparable type

auto c_str = axis::category<std::string>{"red", "blue"};

assert(c_str.index("red") == 0);

assert(c_str.index("blue") == 1);

}

//]

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