time-to-botec/squiggle/node_modules/@stdlib/stats/incr/nansum

incrnansum

Compute a sum incrementally, ignoring NaN values.

The sum is defined as

Usage

var incrnansum = require( '@stdlib/stats/incr/nansum' );

incrnansum()

Returns an accumulator function which incrementally computes a sum, ignoring NaN values.

var accumulator = incrnansum();

accumulator( [x] )

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 = incrnansum();

var sum = accumulator( 2.0 );
// returns 2.0

sum = accumulator( 1.0 );
// returns 3.0

sum = accumulator( NaN );
// returns 3.0

sum = accumulator( 3.0 );
// returns 6.0

sum = accumulator();
// returns 6.0

Notes

• 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.
• For long running accumulations or accumulations of large numbers, care should be taken to prevent overflow.

Examples

var randu = require( '@stdlib/random/base/randu' );
var incrnansum = require( '@stdlib/stats/incr/nansum' );

var accumulator;
var v;
var i;

// Initialize an accumulator:
accumulator = incrnansum();

// For each simulated datum, update the sum...
for ( i = 0; i < 100; i++ ) {
    if ( randu() < 0.2 ) {
        v = NaN;
    } else {
        v = randu() * 100.0;
    }
    accumulator( v );
}
console.log( accumulator() );