# binary2d
> Apply a binary callback to elements in two two-dimensional nested input arrays and assign results to elements in a two-dimensional nested output array.
## Usage
```javascript
var binary2d = require( '@stdlib/array/base/binary2d' );
```
#### binary2d( arrays, shape, fcn )
Applies a binary callback to elements in two two-dimensional nested input arrays and assigns results to elements in a two-dimensional nested output array.
```javascript
var add = require( '@stdlib/number/float64/base/add' );
var zeros2d = require( '@stdlib/array/base/zeros2d' );
var x = [ [ 1.0, 2.0 ], [ 3.0, 4.0 ] ];
var z = zeros2d( [ 2, 2 ] );
var shape = [ 2, 2 ];
binary2d( [ x, x, z ], shape, add );
// z => [ [ 2.0, 4.0 ], [ 6.0, 8.0 ] ]
```
The function accepts the following arguments:
- **arrays**: array-like object containing two input nested arrays and one output nested array.
- **shape**: array shape.
- **fcn**: binary function to apply.
## Notes
- The function assumes that the input and output arrays have the same shape.
## Examples
```javascript
var discreteUniform = require( '@stdlib/random/base/discrete-uniform' ).factory;
var filled2dBy = require( '@stdlib/array/base/filled2d-by' );
var zeros2d = require( '@stdlib/array/base/zeros2d' );
var add = require( '@stdlib/number/float64/base/add' );
var binary2d = require( '@stdlib/array/base/binary2d' );
var shape = [ 3, 3 ];
var x = filled2dBy( shape, discreteUniform( -100, 100 ) );
console.log( x );
var y = filled2dBy( shape, discreteUniform( -100, 100 ) );
console.log( y );
var z = zeros2d( shape );
console.log( z );
binary2d( [ x, y, z ], shape, add );
console.log( z );
```