/// <summary>
/// Smoothes the specified data.
/// </summary>
/// <param name="begin">The begin.</param>
/// <param name="end">The end.</param>
/// <param name="destination">The destination.</param>
template <typename Itertype, typename DestItertype>
void Analyze::smooth( Itertype begin, Itertype end, DestItertype& destination ) {
  auto spots_to_skip { 3 };

  // determine the starting and stopping points for our smoothing process
  auto current = next ( begin, spots_to_skip );
  auto smooth_end = prev ( end, spots_to_skip );

  // direct insert the first 3 elements
  copy ( begin, current, back_inserter ( destination ) );

  // smooth the rest of the elements up to the last three
  transform ( current, smooth_end, back_inserter ( destination ),
  [&]( auto val ) -> int {
    auto result = ( *prev(current, 3) + *prev(current, 2) * 2 + *prev(current, 1) * 3 + val * 3 + *next(current, 1) * 3 +
                    *next(current, 2) * 2 + *next(current, 3) ) / 15;
    current = next ( current );
    return result;
  } );

  // direct insert the last three elements
  copy ( smooth_end, end, back_inserter ( destination ) );
}