# iterExpm1rel > Create an [iterator][mdn-iterator-protocol] which evaluates the [relative error exponential][@stdlib/math/base/special/expm1rel] for each iterated value.
## Usage ```javascript var iterExpm1rel = require( '@stdlib/math/iter/special/expm1rel' ); ``` #### iterExpm1rel( iterator ) Returns an [iterator][mdn-iterator-protocol] which iteratively evaluates the [relative error exponential][@stdlib/math/base/special/expm1rel]. ```javascript var array2iterator = require( '@stdlib/array/to-iterator' ); var it = iterExpm1rel( array2iterator( [ 0.0, 1.0 ] ) ); // returns var v = it.next().value; // returns 1.0 v = it.next().value; // returns ~1.718 // ... ``` 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.
## 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. - If an environment supports `Symbol.iterator` **and** a provided [iterator][mdn-iterator-protocol] is iterable, the returned [iterator][mdn-iterator-protocol] is iterable.
## Examples ```javascript var uniform = require( '@stdlib/random/iter/uniform' ); var iterExpm1rel = require( '@stdlib/math/iter/special/expm1rel' ); // Create a seeded iterator for generating pseudorandom numbers: var rand = uniform( -50.0, 50.0, { 'seed': 1234, 'iter': 10 }); // Create an iterator which consumes the pseudorandom number iterator: var it = iterExpm1rel( rand ); // Perform manual iteration... var v; while ( true ) { v = it.next(); if ( v.done ) { break; } console.log( v.value ); } ```