iterLog1mexp

Create an iterator which iteratively evaluates the natural logarithm of 1-exp(-|x|).

Installation

npm install @stdlib/math-iter-special-log1mexp

Usage

var iterLog1mexp = require( '@stdlib/math-iter-special-log1mexp' );

iterLog1mexp( iterator )

Returns an iterator which iteratively evaluates the natural logarithm of 1-exp(-|x|).

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

var it = iterLog1mexp( array2iterator( [ 0.0, 5.0, 10.0 ] ) );
// returns <Object>

var r = it.next().value;
// returns -Infinity

r = it.next().value;
// returns ~-0.00676

r = it.next().value;
// returns ~-0.00005

// ...

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

• next: function which returns an iterator 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 and returns a single (optional) argument in an iterator protocol-compliant object.

Notes

• If an iterated value is non-numeric (including NaN), the returned iterator returns NaN. If non-numeric iterated values are possible, you are advised to provide an iterator which type checks and handles non-numeric values accordingly.
• If an environment supports Symbol.iterator and a provided iterator is iterable, the returned iterator is iterable.

Examples

var uniform = require( '@stdlib/random-iter-uniform' );
var iterLog1mexp = require( '@stdlib/math-iter-special-log1mexp' );

// Create a seeded iterator for generating pseudorandom numbers:
var rand = uniform( 0.0, 1.0, {
    'seed': 1234,
    'iter': 10
});

// Create an iterator which consumes the pseudorandom number iterator:
var it = iterLog1mexp( rand );

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

See Also

• @stdlib/math-base/special/log1mexp: evaluate the natural logarithm of 1-exp(-|x|).
• @stdlib/math-iter/special/log: create an iterator which computes the base b logarithm.
• @stdlib/math-iter/special/log1p: create an iterator which evaluates the natural logarithm of 1+x for each iterated value.
• @stdlib/math-iter/special/log1pexp: create an iterator which evaluates the natural logarithm of 1+exp(x) for each iterated value.
• @stdlib/math-iter/special/pow: create an iterator which evaluates the exponential function.

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.