H5Utils::hist::HistogramMerger Class Reference

Accumulates UHI histogram groups from multiple source files and writes the merged result once all inputs have been consumed. More...

#include <HistogramMerger.h>

Collaboration diagram for H5Utils::hist::HistogramMerger:

Public Member Functions
	~HistogramMerger ()
void	add (const std::string &path, const H5::Group &src)
	Accumulate one UHI histogram group.
void	write (H5::Group &root) const
	Write every accumulated histogram into the output file.

Private Member Functions
std::unique_ptr< IHistogram >	make (const H5::Group &src)
	Factory: read the storage type from src and return a zero-initialised concrete IHistogram of the appropriate type.

Private Attributes
std::map< std::string, std::unique_ptr< IHistogram > >	m_hists

Detailed Description

Accumulates UHI histogram groups from multiple source files and writes the merged result once all inputs have been consumed.

Usage: HistogramMerger hm; for each source file: hm.add("/path/to/hist", src_group); hm.write(output_root_group);

Definition at line 30 of file HistogramMerger.h.

Constructor & Destructor Documentation

~HistogramMerger()

H5Utils::hist::HistogramMerger::~HistogramMerger ( )

default

Member Function Documentation

add()

void H5Utils::hist::HistogramMerger::add	(	const std::string &	path,
		const H5::Group &	src )

Accumulate one UHI histogram group.

Parameters

path	Full HDF5 object path, e.g. "/jets/mass" (same in all files).
src	The UHI histogram group from a source file.

Definition at line 548 of file HistogramMerger.cxx.

                                                                   {
  if (!m_hists.count(path)) {
    m_hists.emplace(path, make(src));
  }
  m_hists.at(path)->add(src);
}

make()

std::unique_ptr< IHistogram > H5Utils::hist::HistogramMerger::make ( const H5::Group & src )

private

Factory: read the storage type from src and return a zero-initialised concrete IHistogram of the appropriate type.

Definition at line 518 of file HistogramMerger.cxx.

                                        {
  std::vector<Axis>    axes = read_axes(src);
  std::vector<hsize_t> dims = read_dims(src);
 
  H5::Group storage = src.openGroup("storage");
  std::string type = read_str_attr(storage, "type");
 
  if (type == "double") {
    return std::make_unique<SimpleHistogram<double>>(
      std::move(axes), std::move(dims));
  }
  if (type == "int") {
    return std::make_unique<SimpleHistogram<int64_t>>(
      std::move(axes), std::move(dims));
  }
  if (type == "weighted") {
    return std::make_unique<WeightedHistogram>(
      std::move(axes), std::move(dims));
  }
  if (type == "mean") {
    return std::make_unique<MeanHistogram>(
      std::move(axes), std::move(dims));
  }
  if (type == "weighted_mean") {
    return std::make_unique<WeightedMeanHistogram>(
      std::move(axes), std::move(dims));
  }
  throw std::runtime_error("HistogramMerger: unknown UHI storage type: " + type);
}

write()

void H5Utils::hist::HistogramMerger::write

(

H5::Group &

root

)

const

Write every accumulated histogram into the output file.

Parameters

root	The root group of the output file (or any common ancestor).

Definition at line 555 of file HistogramMerger.cxx.

                                               {
  for (const auto& [path, hist] : m_hists) {
    // Split the absolute HDF5 path (e.g. "/a/b/c") into components.
    std::vector<std::string> parts;
    std::istringstream ss(path);
    std::string token;
    while (std::getline(ss, token, '/')) {
      if (!token.empty()) parts.push_back(token);
    }
    if (parts.empty()) continue;
 
    // Navigate/create intermediate groups, then write the histogram.
    H5::Group parent = root;
    for (size_t i = 0; i + 1 < parts.size(); ++i) {
      parent = open_or_create_group(parent, parts[i]);
    }
    hist->write(parent, parts.back());
  }
}

Member Data Documentation

m_hists

std::map<std::string, std::unique_ptr<IHistogram> > H5Utils::hist::HistogramMerger::m_hists

private

Definition at line 48 of file HistogramMerger.h.

---

The documentation for this class was generated from the following files:

• HistogramMerger.h
• HistogramMerger.cxx