ossia::moving_average_filter< T, N > Struct Template Reference

Simple moving average over the last N samples. More...

Detailed Description

template<typename T = float, std::size_t N = 8>
struct ossia::moving_average_filter< T, N >

Simple moving average over the last N samples.

O(1) per sample: the window sum is kept incrementally instead of being recomputed. The accumulator is widened to double for float inputs, because a running sum drifts over a long performance.

Until N samples have been seen the average is taken over what is available, so the output is usable from the first sample on.

Public Types
using	value_type = T
using	accumulator_type = std::conditional_t< std::is_same_v< T, float >, double, T >
	Widened so that the incremental sum does not drift.

Public Member Functions
OSSIA_INLINE void	reset () noexcept
	Forget the history: the next sample restarts the filter.
OSSIA_INLINE void	assign_parameters (const moving_average_filter &) noexcept
	No runtime parameters: the window size is a template argument.
OSSIA_INLINE T	operator() (T x) noexcept

Public Attributes
std::array< T, N >	history {}
	Chronological ring of the window contents.
accumulator_type	sum {}
	Running sum of the first count entries of the window.
std::uint32_t	head {}
	Where the next sample goes in history.
std::uint32_t	count {}
	How many entries of history are valid, saturating at N.