more_algorithms.inl

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//
//
/*
    Copyright (C) 2005- 2005, Hammersmith Imanet Ltd
    This file is part of STIR.
 
    SPDX-License-Identifier: Apache-2.0
 
    See STIR/LICENSE.txt for details
*/
// not nice to have a dependency in buildblock on numerics/norm, but
// we'll bother with that when necessary.
#include "stir/numerics/norm.h"
 
START_NAMESPACE_STIR
 
template <class iterT>
iterT
abs_max_element(iterT start, iterT end)
{
  if (start == end)
    return start;
  iterT current_max_iter = start;
  double current_max = norm_squared(*start);
  iterT iter = start;
  ++iter;
 
  while (iter != end)
    {
      const double n = norm_squared(*iter);
      if (n > current_max)
        {
          current_max = n;
          current_max_iter = iter;
        }
      ++iter;
    }
  return current_max_iter;
}
 
template <class IterT, class elemT>
inline elemT
sum(IterT start, IterT end, elemT init)
{
  elemT tmp = init;
  for (IterT iter = start; iter != end; ++iter)
    tmp += *iter;
  return tmp;
}
 
template <class IterT>
inline typename std::iterator_traits<IterT>::value_type
sum(IterT start, IterT end)
{
  if (start == end)
    {
      typename std::iterator_traits<IterT>::value_type tmp;
      tmp *= 0;
      return tmp;
    }
  return sum(start + 1, end, *start);
}
 
template <class IterT>
inline typename std::iterator_traits<IterT>::value_type
average(IterT start, IterT end)
{
  typename std::iterator_traits<IterT>::value_type tmp = sum(start, end);
  tmp /= (end - start);
  return tmp;
}
 
END_NAMESPACE_STIR