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Common Logarithm

Evaluate the common logarithm.

The common logarithm (logarithm with base 10) is defined for any positive real number as

$$\quad \log_{10} \left( x \right) = y \quad \text{such that} \quad 10^y = x$$

Installation

npm install @stdlib/math-base-special-log10

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

Usage

var log10 = require( '@stdlib/math-base-special-log10' );

log10( x )

Evaluates the common logarithm.

var v = log10( 100.0 );
// returns 2.0

v = log10( 8.0 );
// returns ~0.903

v = log10( 0.0 );
// returns -Infinity

v = log10( Infinity );
// returns Infinity

v = log10( NaN );
// returns NaN

For negative numbers, the common logarithm is not defined.

var v = log10( -4.0 );
// returns NaN

Examples

var randu = require( '@stdlib/random-base-randu' );
var round = require( '@stdlib/math-base-special-round' );
var log10 = require( '@stdlib/math-base-special-log10' );

var x;
var i;

for ( i = 0; i < 100; i++ ) {
    x = round( randu() * 100.0 );
    console.log( 'log10(%d) = %d', x, log10( x ) );
}

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C APIs

Usage

#include "stdlib/math/base/special/log10.h"

stdlib_base_log10( x )

Evaluates the common logarithm.

double out = stdlib_base_log10( 100.0 );
// returns 2.0

out = stdlib_base_log10( 8.0 );
// returns ~0.903

The function accepts the following arguments:

• x: [in] double input value.

double stdlib_base_log10( const double x );

Examples

#include "stdlib/math/base/special/log10.h"
#include <stdlib.h>
#include <stdio.h>

int main() {
    double x;
    double v;
    int i;

    for ( i = 0; i < 100; i++ ) {
        x = ( (double)rand() / (double)RAND_MAX ) * 100.0;
        v = stdlib_base_log10( x );
        printf( "log10(%lf) = %lf\n", x, v );
    }
}

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See Also

• @stdlib/math-base/special/exp10: base 10 exponential function.
• @stdlib/math-base/special/ln: evaluate the natural logarithm of a double-precision floating-point number.
• @stdlib/math-base/special/log: compute the base b logarithm of a double-precision floating-point number.

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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

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Copyright

Copyright © 2016-2024. The Stdlib Authors.