Compute a moving sum incrementally, ignoring
NaNvalues.
For a window of size W, the moving sum is defined as
var incrnanmsum = require( '@stdlib/stats/incr/nanmsum' );Returns an accumulator function which incrementally computes a moving sum. The window parameter defines the number of values over which to compute the moving sum.
var accumulator = incrnanmsum( 3 );If provided an input value x, the accumulator function returns an updated sum. If not provided an input value x, the accumulator function returns the current sum.
var accumulator = incrnanmsum( 3 );
var sum = accumulator();
// returns null
sum = accumulator( 2.0 );
// returns 2.0
sum = accumulator( NaN );
// returns 2.0
sum = accumulator( -5.0 );
// returns -3.0
sum = accumulator( 3.0 );
// returns 0.0
sum = accumulator( 5.0 );
// returns 3.0
sum = accumulator();
// returns 3.0- Input values are not type checked. If non-numeric inputs are possible, you are advised to type check and handle accordingly before passing the value to the accumulator function.
- As
Wvalues are needed to fill the window buffer, the firstW-1returned values are calculated from smaller sample sizes. Until the window is full, each returned value is calculated from all provided values.
var uniform = require( '@stdlib/random/base/uniform' );
var bernoulli = require( '@stdlib/random/base/bernoulli' );
var incrnanmsum = require( '@stdlib/stats/incr/nanmsum' );
// Initialize an accumulator:
var accumulator = incrnanmsum( 5 );
// For each simulated datum, update the moving sum...
var i;
for ( i = 0; i < 100; i++ ) {
accumulator( ( bernoulli( 0.8 ) < 1 ) ? NaN : uniform( -50.0, 50.0 ) );
}
console.log( accumulator() );