Returns an accumulator function which incrementally computes a moving harmonic mean.
W
parameter defines the number of values over which to compute the moving harmonic 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 = incrmhmean( 3 );
var v = accumulator();
// returns null
v = accumulator( 2.0 );
// returns 2.0
v = accumulator( 5.0 );
// returns ~2.86
v = accumulator( 3.0 );
// returns ~2.90
v = accumulator( 5.0 );
// returns ~4.09
v = accumulator();
// returns ~4.09
If provided a value, returns an updated harmonic mean; otherwise, returns the current harmonic mean.
Notes
NaN
or a value which, when used in computations, results inNaN
, the accumulated value isNaN
for all future invocations.value
harmonic mean