time-to-botec/squiggle/node_modules/@stdlib/math/iter/special/atan2/README.md

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# iterAtan2

> Create an [iterator][mdn-iterator-protocol] which iteratively computes the [angle][@stdlib/math/base/special/atan2] in the plane (in radians) between the positive x-axis and the ray from `(0,0)` to the point `(x,y)`.

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## Usage

```javascript
var iterAtan2 = require( '@stdlib/math/iter/special/atan2' );
```

#### iterAtan2( y, x )

Returns an [iterator][mdn-iterator-protocol] which iteratively computes the [angle][@stdlib/math/base/special/atan2] in the plane (in radians) between the positive x-axis and the ray from `(0,0)` to the point `(x,y)`.

```javascript
var array2iterator = require( '@stdlib/array/to-iterator' );

var x = array2iterator( [ 2.0, 2.0, -1.0 ] );
var y = array2iterator( [ 2.0, 6.0, -1.0 ] );

var it = iterAtan2( y, x );
// returns <Object>

var r = it.next().value;
// returns ~0.785

r = it.next().value;
// returns ~1.249

r = it.next().value;
// returns ~-2.356

// ...
```

The returned [iterator][mdn-iterator-protocol] protocol-compliant object has the following properties:

-   **next**: function which returns an [iterator][mdn-iterator-protocol] protocol-compliant object containing the next iterated value (if one exists) assigned to a `value` property and a `done` property having a `boolean` value indicating whether the iterator is finished.
-   **return**: function which closes an [iterator][mdn-iterator-protocol] and returns a single (optional) argument in an [iterator][mdn-iterator-protocol] protocol-compliant object.

If provided a numeric value as an [`iterator`][mdn-iterator-protocol] argument, the value is broadcast as an **infinite** [iterator][mdn-iterator-protocol] which **always** returns the provided value.

```javascript
var array2iterator = require( '@stdlib/array/to-iterator' );

var y = array2iterator( [ 2.0, 6.0 ] );

var it = iterAtan2( y, 2.0 );
// returns <Object>

var v = it.next().value;
// returns ~0.785

v = it.next().value;
// returns ~1.249

var bool = it.next().done;
// returns true
```

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## Notes

-   If an iterated value is non-numeric (including `NaN`), the returned [iterator][mdn-iterator-protocol] returns `NaN`. If non-numeric iterated values are possible, you are advised to provide an [`iterator`][mdn-iterator-protocol] which type checks and handles non-numeric values accordingly.
-   The length of the returned [iterator][mdn-iterator-protocol] is equal to the length of the shortest provided [iterator][mdn-iterator-protocol]. In other words, the returned [iterator][mdn-iterator-protocol] ends once **one** of the provided [iterators][mdn-iterator-protocol] ends.
-   If an environment supports `Symbol.iterator` **and** a provided [iterator][mdn-iterator-protocol] is iterable, the returned [iterator][mdn-iterator-protocol] is iterable.

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## Examples

<!-- eslint no-undef: "error" -->

```javascript
var uniform = require( '@stdlib/random/iter/uniform' );
var iterAtan2 = require( '@stdlib/math/iter/special/atan2' );

// Create seeded iterators for generating pseudorandom numbers:
var x = uniform( -2.0, 2.0, {
    'seed': 1234,
    'iter': 10
});

var y = uniform( -2.0, 2.0, {
    'seed': 4567,
    'iter': 10
});

// Create an iterator which consumes the pseudorandom number iterators:
var it = iterAtan2( y, x );

// Perform manual iteration...
var r;
while ( true ) {
    r = it.next();
    if ( r.done ) {
        break;
    }
    console.log( r.value );
}
```

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[mdn-iterator-protocol]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#The_iterator_protocol

[@stdlib/math/base/special/atan2]: https://www.npmjs.com/package/@stdlib/math/tree/main/base/special/atan2

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