stats.h File Reference

Header for stats.c. More...

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Macros
#define	DEFAULT_STATS_N_EWMA_COUNT   100
#define	stats_update_running_avg(avg, value)    n_count_ewma_double(avg, value, DEFAULT_STATS_N_EWMA_COUNT)

Functions
static double	n_count_ewma_double (double avg, double value, uint64_t N)

Detailed Description

Header for stats.c.

Definition in file stats.h.

Macro Definition Documentation

DEFAULT_STATS_N_EWMA_COUNT

#define DEFAULT_STATS_N_EWMA_COUNT   100

Definition at line 38 of file stats.h.

stats_update_running_avg

#define stats_update_running_avg	(		avg,
			value
	)		n_count_ewma_double(avg, value, DEFAULT_STATS_N_EWMA_COUNT)

Definition at line 39 of file stats.h.

Function Documentation

n_count_ewma_double()

static double n_count_ewma_double ( double  avg, double  value, uint64_t  N  )

inlinestatic

Compute an N-count EWMA, aka N-EWMA. N-EWMA is defined as: EWMA = alpha*value + (1-alpha)*EWMA_prev with alpha = 2/(N+1).

This works out to: EWMA = value*2/(N+1) + EMA_prev*(N-1)/(N+1) = (value*2 + EWMA_prev*(N-1))/(N+1)

Definition at line 23 of file stats.h.