@stdlib/stats-base-dists-lognormal-stdev
v0.3.1TypeScript
Lognormal distribution standard deviation.
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Published by The Stdlib Authors
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About stdlib...
Standard Deviation
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> [Lognormal][lognormal-distribution] distribution [standard deviation][standard-deviation].
The [standard deviation][standard-deviation] for a [lognormal][lognormal-distribution] random variable is
where μ is the location parameter and σ > 0 is the scale parameter. According to the definition, the _natural logarithm_ of a random variable from a
[lognormal distribution][lognormal-distribution] follows a [normal distribution][normal-distribution].
Installation
``bash`
npm install @stdlib/stats-base-dists-lognormal-stdev
Usage
`javascript`
var stdev = require( '@stdlib/stats-base-dists-lognormal-stdev' );
#### stdev( mu, sigma )
Returns the [standard deviation][standard-deviation] for a [lognormal][lognormal-distribution] distribution with location mu and scale sigma.
`javascript
var y = stdev( 2.0, 1.0 );
// returns ~15.969
y = stdev( 0.0, 1.0 );
// returns ~2.161
y = stdev( -1.0, 2.0 );
// returns ~19.901
`
If provided NaN as any argument, the function returns NaN.
`javascript
var y = stdev( NaN, 1.0 );
// returns NaN
y = stdev( 0.0, NaN );
// returns NaN
`
If provided sigma <= 0, the function returns NaN.
`javascript
var y = stdev( 0.0, 0.0 );
// returns NaN
y = stdev( 0.0, -1.0 );
// returns NaN
`
Examples
`javascript
var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var stdev = require( '@stdlib/stats-base-dists-lognormal-stdev' );
var opts = {
'dtype': 'float64'
};
var mu = uniform( 10, -5.0, 5.0, opts );
var sigma = uniform( 10, 0.0, 20.0, opts );
logEachMap( 'µ: %0.4f, σ: %0.4f, SD(X;µ,σ): %0.4f', mu, sigma, stdev );
`
*
C APIs
$3
`c`
#include "stdlib/stats/base/dists/lognormal/stdev.h"
#### stdlib_base_dists_lognormal_stdev( mu, sigma )
Returns the standard deviation for a lognormal distribution with location mu and scale sigma.
`c`
double out = stdlib_base_dists_lognormal_stdev( 0.0, 1.0 );
// returns ~2.161
The function accepts the following arguments:
- mu: [in] double location parameter.[in] double
- sigma: scale parameter.
`c`
double stdlib_base_dists_lognormal_stdev( const double mu, const double sigma );
$3
`c
#include "stdlib/stats/base/dists/lognormal/stdev.h"
#include
#include
static double random_uniform( const double min, const double max ) {
double v = (double)rand() / ( (double)RAND_MAX + 1.0 );
return min + ( v*(max-min) );
}
int main( void ) {
double sigma;
double mu;
double y;
int i;
for ( i = 0; i < 10; i++ ) {
mu = random_uniform( -5.0, 5.0 );
sigma = random_uniform( 0.1, 20.0 );
y = stdlib_base_dists_lognormal_stdev( mu, sigma );
printf("µ: %.4f, σ: %.4f, SD(X; µ, σ): %.4f\n", mu, sigma, y);
}
}
`
*
Notice
This package is part of [stdlib][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][stdlib], see the main project [repository][stdlib].
#### Community
[![Chat][chat-image]][chat-url]
---
License
See [LICENSE][stdlib-license].
Copyright
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
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[stdlib]: https://github.com/stdlib-js/stdlib
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[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules
[deno-url]: https://github.com/stdlib-js/stats-base-dists-lognormal-stdev/tree/deno
[deno-readme]: https://github.com/stdlib-js/stats-base-dists-lognormal-stdev/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/stats-base-dists-lognormal-stdev/tree/umd
[umd-readme]: https://github.com/stdlib-js/stats-base-dists-lognormal-stdev/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/stats-base-dists-lognormal-stdev/tree/esm
[esm-readme]: https://github.com/stdlib-js/stats-base-dists-lognormal-stdev/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/stats-base-dists-lognormal-stdev/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/stats-base-dists-lognormal-stdev/main/LICENSE
[lognormal-distribution]: https://en.wikipedia.org/wiki/Log-normal_distribution
[normal-distribution]: https://en.wikipedia.org/wiki/Normal_distribution
[standard-deviation]: https://en.wikipedia.org/wiki/Standard_deviation