Usage

`javascript
var ztest2 = require( '@stdlib/stats-strided-ztest2' );
`

#### ztest2( NX, NY, alternative, alpha, diff, sigmax, x, strideX, sigmay, y, strideY, out )

Computes a two-sample Z-test.

`javascript
var Results = require( '@stdlib/stats-base-ztest-two-sample-results-float64' );

var x = [ 4.0, 4.0, 6.0, 6.0, 5.0 ];
var y = [ 3.0, 3.0, 5.0, 7.0, 7.0 ];

var results = new Results();
var out = ztest2( x.length, y.length, 'two-sided', 0.05, 0.0, 1.0, x, 1, 2.0, y, 1, results );
// returns {...}

var bool = ( out === results );
// returns true
`

The function has the following parameters:

- NX: number of indexed elements in x.
- NY: number of indexed elements in y.
- alternative: [alternative hypothesis][@stdlib/stats/base/ztest/alternatives].
- alpha: significance level.
- diff: difference in means under the null hypothesis.
- sigmax: known standard deviation of x.
- x: first input array.
- strideX: stride length for x.
- sigmay: known standard deviation of y.
- y: second input array.
- strideY: stride length for y.
- out: output [results object][@stdlib/stats/base/ztest/two-sample/results/float64].

The N and stride parameters determine which elements in the strided arrays are accessed at runtime. For example, to perform a two-sample Z-test over every other element in x and y,

`javascript
var Results = require( '@stdlib/stats-base-ztest-two-sample-results-float64' );

var x = [ 4.0, 0.0, 4.0, 0.0, 6.0, 0.0, 6.0, 0.0, 5.0, 0.0 ];
var y = [ 3.0, 0.0, 3.0, 0.0, 5.0, 0.0, 7.0, 0.0, 7.0, 0.0 ];

var results = new Results();
var out = ztest2( 5, 5, 'two-sided', 0.05, 0.0, 1.0, x, 2, 2.0, y, 2, results );
// returns {...}

var bool = ( out === results );
// returns true
`

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

`javascript
var Results = require( '@stdlib/stats-base-ztest-two-sample-results-float64' );
var Float64Array = require( '@stdlib/array-float64' );

var x0 = new Float64Array( [ 0.0, 4.0, 4.0, 6.0, 6.0, 5.0 ] );
var x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element

var y0 = new Float64Array( [ 0.0, 3.0, 3.0, 5.0, 7.0, 7.0 ] );
var y1 = new Float64Array( y0.buffer, y0.BYTES_PER_ELEMENT*1 ); // start at 2nd element

var results = new Results();
var out = ztest2( 5, 5, 'two-sided', 0.05, 0.0, 1.0, x1, 1, 2.0, y1, 1, results );
// returns {...}

var bool = ( out === results );
// returns true
`

#### ztest2.ndarray( NX, NY, alternative, alpha, diff, sigmax, x, strideX, offsetX, sigmay, y, strideY, offsetY, out )

Computes a two-sample Z-test using alternative indexing semantics.

`javascript
var Results = require( '@stdlib/stats-base-ztest-two-sample-results-float64' );

var x = [ 4.0, 4.0, 6.0, 6.0, 5.0 ];
var y = [ 3.0, 3.0, 5.0, 7.0, 7.0 ];

var results = new Results();
var out = ztest2.ndarray( x.length, y.length, 'two-sided', 0.05, 0.0, 1.0, x, 1, 0, 2.0, y, 1, 0, results );
// returns {...}

var bool = ( out === results );
// returns true
`

The function has the following additional parameters:

- offsetX: starting index for x.
- offsetY: starting index for y.

While [typed array][mdn-typed-array] views mandate a view offset based on the underlying buffer, offset parameters support indexing semantics based on starting indices. For example, to perform a two-sample Z-test over every other element in x and y starting from the second element

`javascript
var Results = require( '@stdlib/stats-base-ztest-two-sample-results-float64' );

var x = [ 0.0, 4.0, 0.0, 4.0, 0.0, 6.0, 0.0, 6.0, 0.0, 5.0 ];
var y = [ 0.0, 3.0, 0.0, 3.0, 0.0, 5.0, 0.0, 7.0, 0.0, 7.0 ];

var results = new Results();
var out = ztest2.ndarray( 5, 5, 'two-sided', 0.05, 0.0, 1.0, x, 2, 1, 2.0, y, 2, 1, results );
// returns {...}

var bool = ( out === results );
// returns true
`