npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

@stdlib/math-base-special-log1p

v0.2.3

Published

Evaluate the natural logarithm of 1+x.

Downloads

175,701

Readme

log1p

NPM version Build Status Coverage Status

Evaluate the natural logarithm of 1+x.

Installation

npm install @stdlib/math-base-special-log1p

Usage

var log1p = require( '@stdlib/math-base-special-log1p' );

log1p( x )

Evaluates the natural logarithm of 1+x.

var v = log1p( 4.0 );
// returns ~1.609

v = log1p( -1.0 );
// returns -Infinity

v = log1p( Infinity );
// returns Infinity

v = log1p( 0.0 );
// returns 0.0

v = log1p( -0.0 );
// returns -0.0

v = log1p( NaN );
// returns NaN

For x < -1, the function returns NaN, as the natural logarithm is not defined for negative numbers.

var v = log1p( -2.0 );
// returns NaN

Examples

var randu = require( '@stdlib/random-base-randu' );
var round = require( '@stdlib/math-base-special-round' );
var log1p = require( '@stdlib/math-base-special-log1p' );

var x;
var i;

for ( i = 0; i < 100; i++ ) {
    x = round( randu() * 100.0 );
    console.log( log1p( x ) );
}

C APIs

Usage

#include "stdlib/math/base/special/log1p.h"

stdlib_base_log1p( x )

Evaluates the natural logarithm of 1+x.

double out = stdlib_base_log1p( 4.0 );
// returns ~1.609

out = stdlib_base_log1p( -1.0 );
// returns -Infinity

The function accepts the following arguments:

  • x: [in] double input value.
double stdlib_base_log1p( const double x );

Examples

#include "stdlib/math/base/special/log1p.h"
#include <stdlib.h>
#include <stdio.h>

int main( void ) {
    double x;
    double v;
    int i;
    
    for ( i = 0; i < 100; i++ ) {
        x = ( (double)rand() / (double)RAND_MAX ) * 100.0;
        v = stdlib_base_log1p( x );
        printf( "log1p(%lf) = %lf\n", x, v );
    }
}

See Also


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

Chat


Copyright

Copyright © 2016-2024. The Stdlib Authors.