itersum

Compute the sum of all iterated values.

The sum is defined as

s equals sigma-summation Underscript i equals 0 Overscript n minus 1 Endscripts x Subscript i

Usage

var itersum = require( '@stdlib/stats/iter/sum' );

itersum( iterator )

Computes the sum of all iterated values.

var array2iterator = require( '@stdlib/array/to-iterator' );

var arr = array2iterator( [ 1.0, 2.0, -3.5, 4.0 ] );

var s = itersum( arr );
// returns 3.5

Notes

  • If an iterated value is non-numeric (including NaN), the returned iterator returns NaN. If non-numeric iterated values are possible, you are advised to provide an iterator which type checks and handles non-numeric values accordingly.
  • For iterators which can generate many values or which may output large numbers, care should be taken to prevent overflow.

Examples

var runif = require( '@stdlib/random/iter/uniform' );
var itersum = require( '@stdlib/stats/iter/sum' );

// Create an iterator for generating uniformly distributed pseudorandom numbers:
var rand = runif( -10.0, 10.0, {
    'seed': 1234,
    'iter': 100
});

// Compute the sum:
var s = itersum( rand );
// returns <number>

console.log( 'Sum: %d.', s );