Nondeterministic Polynomial Munchies

# npm

## @stdlib/math-base-special-trigamma

0.0.5 • Public • Published

# Trigamma

Trigamma function.

The trigamma function `ψ^(1)` is the derivative of the digamma function.

## Installation

`npm install @stdlib/math-base-special-trigamma`

## Usage

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

#### trigamma( x )

Evaluates the trigamma function.

```var v = trigamma( -2.5 );
// returns ~9.539

v = trigamma( 1.0 );
// returns ~1.645

v = trigamma( 10.0 );
// returns ~0.105```

If `x` is `0` or a negative `integer`, the function returns `NaN`.

```var v = trigamma( 0.0 );
// returns NaN

v = trigamma( -1.0 );
// returns NaN

v = trigamma( -2.0 );
// returns NaN```

If provided `NaN`, the function returns `NaN`.

```var v = trigamma( NaN );
// returns NaN```

## Examples

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

var x;
var v;
var i;

for ( i = 0; i < 10; i++ ) {
x = (randu()*100.0) - 50.0;
v = trigamma( x );
console.log( 'x: %d, ψ^(1)(x): %d', x, v );
}```

## 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.

## Keywords

### Install

`npm i @stdlib/math-base-special-trigamma`

stdlib.io

7

### Version

0.0.5

Apache-2.0 AND BSL-1.0

62.3 kB

15