@stdlib/stats-base-dists-discrete-uniform-mean
v0.3.1TypeScript
Discrete uniform distribution expected value.
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Published by The Stdlib Authors
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About stdlib...
Mean
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> [Discrete uniform][discrete-uniform-distribution] distribution [expected value][expected-value].
The [expected value][expected-value] for a [discrete uniform][discrete-uniform-distribution] random variable is
where a is the minimum support and b the maximum support of the distribution.
Installation
``bash`
npm install @stdlib/stats-base-dists-discrete-uniform-mean
Usage
`javascript`
var mean = require( '@stdlib/stats-base-dists-discrete-uniform-mean' );
#### mean( a, b )
Returns the [expected value][expected-value] of a [discrete uniform][discrete-uniform-distribution] distribution with parameters a (minimum support) and b (maximum support).
`javascript
var v = mean( 0, 1 );
// returns 0.5
v = mean( 4, 12 );
// returns 8.0
v = mean( 2, 8 );
// returns 5.0
`
If a or b is not an integer value, the function returns NaN.
`javascript
var v = mean( 0.1, 2 );
// returns NaN
v = mean( 0, 2.2 );
// returns NaN
v = mean( NaN, 2 );
// returns NaN
v = mean( 2, NaN );
// returns NaN
`
If provided a > b, the function returns NaN.
`javascript
var y = mean( 3, 2 );
// returns NaN
y = mean( -1, -2 );
// returns NaN
`
Examples
`javascript
var randu = require( '@stdlib/random-base-randu' );
var round = require( '@stdlib/math-base-special-round' );
var mean = require( '@stdlib/stats-base-dists-discrete-uniform-mean' );
var a;
var b;
var v;
var i;
for ( i = 0; i < 10; i++ ) {
a = round( randu()*10.0 );
b = round( ( randu()*10.0 ) + a );
v = mean( a, b );
console.log( 'a: %d, b: %d, E(X;a,b): %d', a.toFixed( 4 ), b.toFixed( 4 ), v.toFixed( 4 ) );
}
`
*
C APIs
$3
`c`
#include "stdlib/stats/base/dists/discrete-uniform/mean.h"
#### stdlib_base_dists_discrete_uniform_mean( a, b )
Returns the [expected value][expected-value] of a [discrete uniform][discrete-uniform-distribution] distribution with parameters a (minimum support) and b (maximum support).
`c`
double out = stdlib_base_dists_discrete_uniform_mean( 0, 1 );
// returns 0.5
The function accepts the following arguments:
- a: [in] int32_t minimum support.[in] int32_t
- b: maximum support.
`c`
double stdlib_base_dists_discrete_uniform_mean( const int32_t a, const int32_t b );
$3
`c
#include "stdlib/stats/base/dists/discrete-uniform/mean.h"
#include "stdlib/math/base/special/round.h"
#include
#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 ) {
int32_t a;
int32_t b;
double y;
int i;
for ( i = 0; i < 10; i++ ) {
a = stdlib_base_round( random_uniform( 0.0, 10.0 ) );
b = stdlib_base_round( random_uniform( 0.0, 10.0 ) ) + a;
y = stdlib_base_dists_discrete_uniform_mean( a, b );
printf( "a: %d, b: %d, E(X;a,b): %lf\n", a, b, 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-discrete-uniform-mean/tree/deno
[deno-readme]: https://github.com/stdlib-js/stats-base-dists-discrete-uniform-mean/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/stats-base-dists-discrete-uniform-mean/tree/umd
[umd-readme]: https://github.com/stdlib-js/stats-base-dists-discrete-uniform-mean/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/stats-base-dists-discrete-uniform-mean/tree/esm
[esm-readme]: https://github.com/stdlib-js/stats-base-dists-discrete-uniform-mean/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/stats-base-dists-discrete-uniform-mean/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/stats-base-dists-discrete-uniform-mean/main/LICENSE
[discrete-uniform-distribution]: https://en.wikipedia.org/wiki/Discrete_uniform_distribution
[expected-value]: https://en.wikipedia.org/wiki/Expected_value