stdlib-js
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About stdlib...
</summary>
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ln
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Evaluate the [natural logarithm][natural-logarithm] of a double-precision floating-point number.
bash
npm install @stdlib/math-base-special-ln
javascript
var ln = require( '@stdlib/math-base-special-ln' );
#### ln( x )
Evaluates the [natural logarithm][natural-logarithm] of a double-precision floating-point number.
javascript
var v = ln( 4.0 );
// returns ~1.386
v = ln( 0.0 );
// returns -Infinity
v = ln( Infinity );
// returns Infinity
v = ln( NaN );
// returns NaN
For negative numbers, the [natural logarithm][natural-logarithm] is not defined.
javascript
var v = ln( -4.0 );
// returns NaN
javascript
var randu = require( '@stdlib/random-base-randu' );
var round = require( '@stdlib/math-base-special-round' );
var ln = require( '@stdlib/math-base-special-ln' );
var x;
var i;
for ( i = 0; i < 100; i++ ) {
x = round( randu() * 100.0 );
console.log( 'ln(%d) = %d', x, ln( x ) );
}
c
#include "stdlib/math/base/special/ln.h"
#### stdlib_base_ln( x )
Evaluates the [natural logarithm][natural-logarithm] of a double-precision floating-point number.
c
double v = stdlib_base_ln( 2.0 );
// returns ~0.693
The function accepts the following arguments:
- x: [in] double input value.
c
double stdlib_base_ln( const double x );
c
#include "stdlib/math/base/special/ln.h"
#include <stdlib.h>
#include <stdio.h>
int main( void ) {
double out;
double x;
int i;
for ( i = 0; i < 100; i++ ) {
x = ( (double)rand() / (double)RAND_MAX ) * 100.0;
out = stdlib_base_ln( x );
printf( "ln(%lf) = %lf\n", x, out );
}
}
@stdlib/math-base/special/exp][@stdlib/math/base/special/exp]: natural exponential function.
- [@stdlib/math-base/special/log10][@stdlib/math/base/special/log10]: common logarithm (base ten).
- [@stdlib/math-base/special/log1p][@stdlib/math/base/special/log1p]: evaluate the natural logarithm of 1+x.
- [@stdlib/math-base/special/log2][@stdlib/math/base/special/log2]: binary logarithm (base 2).
