Returns an accumulator function which incrementally computes a moving arithmetic mean.
W
parameter defines the number of values over which to compute the moving mean.W
values are needed to fill the window buffer, the first W-1
returned values are calculated from smaller sample sizes. Until the window is full, each returned value is calculated from all provided values.window size
accumulator function
var accumulator = incrmmean( 3 );
var mu = accumulator();
// returns null
mu = accumulator( 2.0 );
// returns 2.0
mu = accumulator( -5.0 );
// returns -1.5
mu = accumulator( 3.0 );
// returns 0.0
mu = accumulator( 5.0 );
// returns 1.0
mu = accumulator();
// returns 1.0
If provided a value, returns an updated arithmetic mean; otherwise, returns the current arithmetic mean.
Notes
NaN
or a value which, when used in computations, results inNaN
, the accumulated value isNaN
for all future invocations.value
arithmetic mean