Usage

`javascript
var dnanmeanpn = require( '@stdlib/stats-strided-dnanmeanpn' );
`

#### dnanmeanpn( N, x, strideX )

Computes the [arithmetic mean][arithmetic-mean] of a double-precision floating-point strided array x, ignoring NaN values and using a two-pass error correction algorithm.

`javascript
var Float64Array = require( '@stdlib/array-float64' );

var x = new Float64Array( [ 1.0, -2.0, NaN, 2.0 ] );

var v = dnanmeanpn( x.length, x, 1 );
// returns ~0.3333
`

The function has the following parameters:

- N: number of indexed elements.
- x: input [Float64Array][@stdlib/array/float64].
- strideX: stride length for x.

The N and stride parameters determine which elements in the strided array are accessed at runtime. For example, to compute the [arithmetic mean][arithmetic-mean] of every other element in x,

`javascript
var Float64Array = require( '@stdlib/array-float64' );

var x = new Float64Array( [ 1.0, 2.0, 2.0, -7.0, -2.0, 3.0, 4.0, 2.0, NaN, NaN ] );

var v = dnanmeanpn( 5, x, 2 );
// returns 1.25
`

Note that indexing is relative to the first index. To introduce an offset, use [typed array][mdn-typed-array] views.

`javascript
var Float64Array = require( '@stdlib/array-float64' );

var x0 = new Float64Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0, NaN, NaN ] );
var x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element

var v = dnanmeanpn( 5, x1, 2 );
// returns 1.25
`

#### dnanmeanpn.ndarray( N, x, strideX, offsetX )

Computes the [arithmetic mean][arithmetic-mean] of a double-precision floating-point strided array, ignoring NaN values and using a two-pass error correction algorithm and alternative indexing semantics.

`javascript
var Float64Array = require( '@stdlib/array-float64' );

var x = new Float64Array( [ 1.0, -2.0, NaN, 2.0 ] );

var v = dnanmeanpn.ndarray( x.length, x, 1, 0 );
// returns ~0.33333
`

The function has the following additional parameters:

- offsetX: starting index for x.

While [typed array][mdn-typed-array] views mandate a view offset based on the underlying buffer, the offset parameter supports indexing semantics based on a starting index. For example, to calculate the [arithmetic mean][arithmetic-mean] for every other element in x starting from the second element

`javascript
var Float64Array = require( '@stdlib/array-float64' );

var x = new Float64Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0, NaN, NaN ] );

var v = dnanmeanpn.ndarray( 5, x, 2, 1 );
// returns 1.25
`