Usage

`javascript
var sumSeries = require( '@stdlib/math-base-tools-sum-series' );
`

#### sumSeries( generator\[, options ] )

Computes the sum of the series given by the supplied generator argument. generator can be either an ES6 [Generator object][es6-generator] or a function which returns successive elements of the series at each invocation.

Using an ES6 [Generator object][es6-generator]:

`javascript
var pow = require( '@stdlib/math-base-special-pow' );
var gen = geometricSeriesGenerator( 0.9 );
var out = sumSeries( gen );
// returns 10

function* geometricSeriesGenerator( x ) {
var exponent = 0;
while ( true ) {
yield pow( x, exponent );
exponent += 1;
}
}
`

Alternatively, one can use a closure to achieve the same goal:

`javascript
var pow = require( '@stdlib/math-base-special-pow' );
var gen = geometricSeriesClosure( 0.9 );
var out = sumSeries( gen );
// returns 10

function geometricSeriesClosure( x ) {
var exponent = -1;
return gen;

function gen() {
exponent += 1;
return pow( x, exponent );
}
}
`

The function accepts the following options:

- maxTerms: integer denoting the maximum number of terms to be summed. Default: 1000000.
- tolerance: number specifying the tolerance used to assess convergence. Default: 2.22e-16.
- initialValue: number specifying the initial value of the returned sum. Default: 0.

By default, the initial value of the sum is 0. To choose a different one, use the initialValue option.

`javascript
var pow = require( '@stdlib/math-base-special-pow' );

var out = sumSeries( geometricSeriesClosure( 0.5 ), {
'initialValue': 1
});
// returns 3

function geometricSeriesClosure( x ) {
var exponent = -1;
return gen;

function gen() {
exponent += 1;
return pow( x, exponent );
}
}
`

To change the maximum number of terms to be summed, set the maxTerms option.

`javascript
var pow = require( '@stdlib/math-base-special-pow' );

// Note: infinite sum is 2
var out = sumSeries( geometricSeriesClosure( 0.5 ), {
'maxTerms': 10
});
// returns ~1.998

function geometricSeriesClosure( x ) {
var exponent = -1;
return gen;

function gen() {
exponent += 1;
return pow( x, exponent );
}
}
`

The default tolerance of 2.22e-16 used to assess convergence can be changed via the tolerance option.

`javascript
var pow = require( '@stdlib/math-base-special-pow' );

var out = sumSeries( geometricSeriesClosure( 0.5 ), {
'tolerance': 1e-3
});
// returns ~1.998

function geometricSeriesClosure( x ) {
var exponent = -1;
return gen;

function gen() {
exponent += 1;
return pow( x, exponent );
}
}
`