You might be interested in the modern and more mature boost::histogram header only library.

Histogram

Histogram in C++11, 1D, simple header-only, inspired by R, calculate and optimize breaks automatically. Accepts different precissions.

Documentation

Doxygen generated Docs

Warning, docs are not generated automatically and might be outdated.

Downloading

You can use the header as is, just download it, and include it in your project. MIT License, but please contribute back if you add any extra feature!

Using it.

You should read the test file as a sample for usage.

vector<double> data{1.0, 1.0, 2.0, 3.0, 19.0, 0.5, 14.0};
histo::Histo<double> h_scott(data); // Default method to calculate Breaks.
size_t bins = 10;
auto breaks_with_bins = histo::GenerateBreaksFromRangeAndBins<double>(0.0, 20.0, bins);
double width = 1.0;
auto breaks_with_fixed_width = histo::GenerateBreaksFromRangeAndWidth<double>(0.0, 20.0, width);
histo::Histo<double> h_with_bins(data, breaks_with_bins);
histo::Histo<double> h_with_width(data, breaks_with_width);

Each histogram has public members: bins, breaks, counts and range. We can fill the histogram with FillCounts(data), called at constructor. The data is not stored in the histogram.

We can fill the bins with more data to an existing histogram.

vector<double> extra_data{7.0, 13.0};
h_with_bins.FillCounts(extra_data);

We can also normalize the histogram to get a probability density function from it.

histo::Histo<double, unsigned int> regular_histo(data);
histo::Histo<double, double> normalized_histogram = histo::NormalizeByArea(regular_histo);

Optionally, we can use VTK (vtkChartXY) to visualize the histogram.

vector<double> data{0.0, 1.0, 1.0,1.0, 2.0, 3.0, 5.0, 5.0, 8.0, 8.0,  12.0};
Histo<double> h(data, histo::GenerateBreaksFromRangeAndBins<double>(0.0,15.0, 5));
h.PrintBreaksAndCounts(std::cout);
h.name = "withJustData";
visualize_histo(h, vtkChart::LINE);
visualize_histo(h, vtkChart::BAR);

Test

All the features are tested using gtest.