add boost on mac

macx64/include/boost/histogram/algorithm/reduce.hpp

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+// 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)
+
+#ifndef BOOST_HISTOGRAM_ALGORITHM_REDUCE_HPP
+#define BOOST_HISTOGRAM_ALGORITHM_REDUCE_HPP
+
+#include <boost/assert.hpp>
+#include <boost/histogram/detail/axes.hpp>
+#include <boost/histogram/detail/meta.hpp>
+#include <boost/histogram/fwd.hpp>
+#include <boost/histogram/indexed.hpp>
+#include <boost/histogram/unsafe_access.hpp>
+#include <boost/throw_exception.hpp>
+#include <cmath>
+#include <limits>
+#include <stdexcept>
+#include <type_traits>
+
+namespace boost {
+namespace histogram {
+namespace algorithm {
+
+/**
+  Option type returned by the helper functions shrink_and_rebin(), shrink(), rebin().
+ */
+struct reduce_option {
+#ifndef BOOST_HISTOGRAM_DOXYGEN_INVOKED
+  unsigned iaxis = 0;
+  double lower, upper;
+  unsigned merge = 0;
+
+  reduce_option() noexcept = default;
+
+  reduce_option(unsigned i, double l, double u, unsigned m)
+      : iaxis(i), lower(l), upper(u), merge(m) {
+    if (lower == upper)
+      BOOST_THROW_EXCEPTION(std::invalid_argument("lower != upper required"));
+    if (merge == 0) BOOST_THROW_EXCEPTION(std::invalid_argument("merge > 0 required"));
+  }
+#endif
+};
+
+/**
+  Shrink and rebin option.
+
+  @param iaxis which axis to operate on.
+  @param lower lowest bound that should be kept.
+  @param upper highest bound that should be kept. If upper is inside bin interval, the
+  whole interval is removed.
+  @param merge how many adjacent bins to merge into one.
+ */
+inline auto shrink_and_rebin(unsigned iaxis, double lower, double upper, unsigned merge) {
+  return reduce_option{iaxis, lower, upper, merge};
+}
+
+/**
+  Shrink option.
+
+  @param iaxis which axis to operate on.
+  @param lower lowest bound that should be kept.
+  @param upper highest bound that should be kept. If upper is inside bin interval, the
+  whole interval is removed.
+ */
+inline auto shrink(unsigned iaxis, double lower, double upper) {
+  return reduce_option{iaxis, lower, upper, 1};
+}
+
+/**
+  Rebin option.
+
+  @param iaxis which axis to operate on.
+  @param merge how many adjacent bins to merge into one.
+ */
+inline auto rebin(unsigned iaxis, unsigned merge) {
+  return reduce_option{iaxis, std::numeric_limits<double>::quiet_NaN(),
+                       std::numeric_limits<double>::quiet_NaN(), merge};
+}
+
+/**
+  Convenience overload for single axis.
+
+  @param lower lowest bound that should be kept.
+  @param upper highest bound that should be kept. If upper is inside bin interval, the
+  whole interval is removed.
+  @param merge how many adjacent bins to merge into one.
+*/
+inline auto shrink_and_rebin(double lower, double upper, unsigned merge) {
+  return shrink_and_rebin(0, lower, upper, merge);
+}
+
+/**
+  Convenience overload for single axis.
+
+  @param lower lowest bound that should be kept.
+  @param upper highest bound that should be kept. If upper is inside bin interval, the
+  whole interval is removed.
+*/
+inline auto shrink(double lower, double upper) { return shrink(0, lower, upper); }
+
+/**
+  Convenience overload for single axis.
+
+  @param merge how many adjacent bins to merge into one.
+*/
+inline auto rebin(unsigned merge) { return rebin(0, merge); }
+
+/**
+  Shrink and/or rebin axes of a histogram.
+
+  Returns the reduced copy of the histogram.
+
+  @param hist original histogram.
+  @param options iterable sequence of reduce_options, generated by shrink_and_rebin(),
+  shrink(), and rebin().
+ */
+#ifndef BOOST_HISTOGRAM_DOXYGEN_INVOKED
+template <class Histogram, class Iterable, class = detail::requires_iterable<Iterable>>
+#else
+template <class Histogram, class Iterable>
+#endif
+decltype(auto) reduce(const Histogram& hist, const Iterable& options) {
+  const auto& old_axes = unsafe_access::axes(hist);
+
+  struct option_item : reduce_option {
+    int begin, end;
+  };
+
+  auto opts = detail::make_stack_buffer<option_item>(old_axes);
+  for (const auto& o : options) {
+    auto& oi = opts[o.iaxis];
+    if (oi.merge > 0) // did we already set the option for this axis?
+      BOOST_THROW_EXCEPTION(std::invalid_argument("indices must be unique"));
+    oi.lower = o.lower;
+    oi.upper = o.upper;
+    oi.merge = o.merge;
+  }
+
+  // make new axes container with default-constructed axis instances
+  auto axes = detail::make_default(old_axes);
+  detail::static_if<detail::is_tuple<decltype(axes)>>(
+      [](auto&, const auto&) {},
+      [](auto& axes, const auto& old_axes) {
+        axes.reserve(old_axes.size());
+        for (const auto& a : old_axes) axes.emplace_back(detail::make_default(a));
+      },
+      axes, old_axes);
+
+  // override default-constructed axis instances with modified instances
+  unsigned iaxis = 0;
+  hist.for_each_axis([&](const auto& a) {
+    using T = detail::remove_cvref_t<decltype(a)>;
+
+    auto& o = opts[iaxis];
+    o.begin = 0;
+    o.end = a.size();
+    if (o.merge > 0) { // option is set?
+      if (o.lower < o.upper) {
+        while (o.begin != o.end && a.value(o.begin) < o.lower) ++o.begin;
+        while (o.end != o.begin && a.value(o.end - 1) >= o.upper) --o.end;
+      } else if (o.lower > o.upper) {
+        // for inverted axis::regular
+        while (o.begin != o.end && a.value(o.begin) > o.lower) ++o.begin;
+        while (o.end != o.begin && a.value(o.end - 1) <= o.upper) --o.end;
+      }
+      o.end -= (o.end - o.begin) % o.merge;
+      auto a2 = T(a, o.begin, o.end, o.merge);
+      axis::get<T>(detail::axis_get(axes, iaxis)) = a2;
+    } else {
+      o.merge = 1;
+      axis::get<T>(detail::axis_get(axes, iaxis)) = a;
+    }
+    ++iaxis;
+  });
+
+  auto storage = detail::make_default(unsafe_access::storage(hist));
+  auto result = Histogram(std::move(axes), std::move(storage));
+
+  auto idx = detail::make_stack_buffer<int>(unsafe_access::axes(result));
+  for (auto x : indexed(hist, coverage::all)) {
+    auto i = idx.begin();
+    auto o = opts.begin();
+    for (auto j : x.indices()) {
+      *i = (j - o->begin);
+      if (*i <= -1)
+        *i = -1;
+      else {
+        *i /= o->merge;
+        const int end = (o->end - o->begin) / o->merge;
+        if (*i > end) *i = end;
+      }
+      ++i;
+      ++o;
+    }
+    result.at(idx) += *x;
+  }
+
+  return result;
+}
+
+/**
+  Shrink and/or rebin axes of a histogram.
+
+  Returns the modified copy.
+
+  @param hist original histogram.
+  @param opt  reduce option generated by shrink_and_rebin(), shrink(), and rebin().
+  @param opts more reduce_options.
+ */
+template <class Histogram, class... Ts>
+decltype(auto) reduce(const Histogram& hist, const reduce_option& opt, Ts&&... opts) {
+  // this must be in one line, because any of the ts could be a temporary
+  return reduce(hist, std::initializer_list<reduce_option>{opt, opts...});
+}
+
+} // namespace algorithm
+} // namespace histogram
+} // namespace boost
+
+#endif