histogram/examples/getting_started_listing_03.cpp
2019-06-08 19:02:16 +02:00

55 lines
1.5 KiB
C++

// 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)
// clang-format off
//[ getting_started_listing_03
#include <boost/format.hpp>
#include <boost/histogram.hpp>
#include <cassert>
#include <iostream>
#include <sstream>
int main() {
using namespace boost::histogram;
/*
Create a profile. Profiles does not only count entries in each cell, but
also compute the mean of a sample value in each cell.
*/
auto p = make_profile(axis::regular<>(5, 0.0, 1.0));
/*
Fill profile with data, usually this happens in a loop. You pass the sample
with the `sample` helper function. The sample can be the first or last
argument.
*/
p(0.1, sample(1));
p(0.15, sample(3));
p(0.2, sample(4));
p(0.9, sample(5));
/*
Iterate over bins and print profile.
*/
std::ostringstream os;
for (auto&& x : indexed(p)) {
os << boost::format("bin %i [%3.1f, %3.1f) count %i mean %g\n")
% x.index() % x.bin().lower() % x.bin().upper()
% x->count() % x->value();
}
std::cout << os.str() << std::flush;
assert(os.str() == "bin 0 [0.0, 0.2) count 2 mean 2\n"
"bin 1 [0.2, 0.4) count 1 mean 4\n"
"bin 2 [0.4, 0.6) count 0 mean 0\n"
"bin 3 [0.6, 0.8) count 0 mean 0\n"
"bin 4 [0.8, 1.0) count 1 mean 5\n");
}
//]