1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
|
// Copyright 2015-2018 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_histogram_reduction
#include <boost/histogram.hpp>
#include <cassert>
int main() {
using namespace boost::histogram;
// make a 2d histogram
auto h = make_histogram(axis::regular<>(4, 0.0, 4.0), axis::regular<>(4, -1.0, 1.0));
h(0, -0.9);
h(1, 0.9);
h(2, 0.1);
h(3, 0.1);
// shrink the first axis to remove the highest bin
// rebin the second axis by merging pairs of adjacent bins
auto h2 = algorithm::reduce(h, algorithm::shrink(0, 0.0, 3.0), algorithm::rebin(1, 2));
assert(h2.axis(0).size() == 3);
assert(h2.axis(0).bin(0).lower() == 0.0);
assert(h2.axis(0).bin(2).upper() == 3.0);
assert(h2.axis(1).size() == 2);
assert(h2.axis(1).bin(0).lower() == -1.0);
assert(h2.axis(1).bin(1).upper() == 1.0);
// reduce does not change the total count if the histogram has underflow/overflow bins;
// counts in removed bins are added to the corresponding under- and overflow bins
assert(algorithm::sum(h) == 4 && algorithm::sum(h2) == 4);
}
//]
|
