# nansLike
> Create a NaN-filled [ndarray][@stdlib/ndarray/ctor] having the same shape and [data type][@stdlib/ndarray/dtypes] as a provided ndarray.
## Usage
```javascript
var nansLike = require( '@stdlib/ndarray/nans-like' );
```
#### nansLike( x\[, options] )
Creates a NaN-filled [ndarray][@stdlib/ndarray/ctor] having the same shape and [data type][@stdlib/ndarray/dtypes] as a provided ndarray.
```javascript
var getShape = require( '@stdlib/ndarray/shape' );
var getDType = require( '@stdlib/ndarray/dtype' );
var zeros = require( '@stdlib/ndarray/zeros' );
var x = zeros( [ 2, 2 ] );
// returns [ [ 0.0, 0.0 ], [ 0.0, 0.0 ] ]
var y = nansLike( x );
// returns [ [ NaN, NaN ], [ NaN, NaN ] ]
var sh = getShape( y );
// returns [ 2, 2 ]
var dt = String( getDType( y ) );
// returns 'float64'
```
The function supports the following options:
- **dtype**: output [ndarray][@stdlib/ndarray/ctor] [data type][@stdlib/ndarray/dtypes]. Must be a floating-point or "generic" [data type][@stdlib/ndarray/dtypes]. Overrides the input ndarray's inferred [data type][@stdlib/ndarray/dtypes].
- **shape**: output [ndarray][@stdlib/ndarray/ctor] shape. Overrides the input ndarray's inferred shape.
- **order**: specifies whether the output [ndarray][@stdlib/ndarray/ctor] should be `'row-major'` (C-style) or `'column-major'` (Fortran-style). Overrides the input ndarray's inferred order.
- **mode**: specifies how to handle indices which exceed array dimensions (see [ndarray][@stdlib/ndarray/ctor]). Default: `'throw'`.
- **submode**: a mode array which specifies for each dimension how to handle subscripts which exceed array dimensions (see [ndarray][@stdlib/ndarray/ctor]). If provided fewer modes than dimensions, the constructor recycles modes using modulo arithmetic. Default: `[ options.mode ]`.
- **readonly**: boolean indicating whether an array should be **read-only**. Default: `false`.
To override either the `dtype`, `shape`, or `order`, specify the corresponding option. For example, to override the inferred [data type][@stdlib/ndarray/dtypes],
```javascript
var getShape = require( '@stdlib/ndarray/shape' );
var getDType = require( '@stdlib/ndarray/dtype' );
var zeros = require( '@stdlib/ndarray/zeros' );
var x = zeros( [ 2, 2 ] );
// returns [ [ 0.0, 0.0 ], [ 0.0, 0.0 ] ]
var dt = String( getDType( x ) );
// returns 'float64'
var y = nansLike( x, {
'dtype': 'float32'
});
// returns [ [ NaN, NaN ], [ NaN, NaN ] ]
var sh = getShape( y );
// returns [ 2, 2 ]
dt = String( getDType( y ) );
// returns 'float32'
```
## Examples
```javascript
var zeros = require( '@stdlib/ndarray/zeros' );
var ndarray2array = require( '@stdlib/ndarray/to-array' );
var nansLike = require( '@stdlib/ndarray/nans-like' );
// Specify a list of data types:
var dt = [
'float64',
'float32',
'complex128',
'complex64',
'generic'
];
// Generate NaN-filled arrays...
var x;
var y;
var i;
for ( i = 0; i < dt.length; i++ ) {
x = zeros( [ 2, 2 ], {
'dtype': dt[ i ]
});
y = nansLike( x );
console.log( ndarray2array( y ) );
}
```
[@stdlib/ndarray/ctor]: https://github.com/stdlib-js/ndarray/tree/main/ctor
[@stdlib/ndarray/dtypes]: https://github.com/stdlib-js/ndarray/tree/main/dtypes