Trigamma

Trigamma function for a single-precision floating-point number.

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

Installation

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

Usage

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

trigammaf( x )

Evaluates the trigamma function for a single-precision floating-point number.

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

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

v = trigammaf( 10.0 );
// returns ~0.105

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

var v = trigammaf( 0.0 );
// returns NaN

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

v = trigammaf( -2.0 );
// returns NaN

If provided NaN, the function returns NaN.

var v = trigammaf( NaN );
// returns NaN

Examples

var uniform = require( '@stdlib/random-array-uniform' );
var logEachMap = require( '@stdlib/console-log-each-map' );
var trigammaf = require( '@stdlib/math-base-special-trigammaf' );

var opts = {
    'dtype': 'float32'
};
var x = uniform( 100, -50.0, 50.0, opts );

logEachMap( 'x: %0.4f, ψ^(1)(x): %0.4f', x, trigammaf );

C APIs

Usage

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

stdlib_base_trigammaf( x )

Evaluates the trigamma function for a single-precision floating-point number.

float out = stdlib_base_trigammaf( -2.5f );
// returns ~9.539f

out = stdlib_base_trigammaf( 1.0f );
// returns ~1.645f

The function accepts the following arguments:

• x: [in] float input value.

float stdlib_base_trigammaf( const float x );

Examples

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

int main( void ) {
    const float x[] = { 4.0f, -1.5f, -0.5f, 0.5f };

    float y;
    int i;
    for ( i = 0; i < 4; i++ ) {
        y = stdlib_base_trigammaf( x[ i ] );
        printf( "x: %f, ψ^(1)(x): %f\n", x[ i ], y );
    }
}

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.

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Copyright

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