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ahaversinf

Compute the inverse half-value versed sine of a single-precision floating-point number.

The inverse half-value versed sine is defined as

$$\mathop{\mathrm{ahaversin}}(\theta) = 2 \cdot \arcsin(\sqrt{\theta})$$

Installation

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

Alternatively,

• To load the package in a website via a script tag without installation and bundlers, use the ES Module available on the esm branch (see README).
• If you are using Deno, visit the deno branch (see README for usage intructions).
• For use in Observable, or in browser/node environments, use the Universal Module Definition (UMD) build available on the umd branch (see README).

The branches.md file summarizes the available branches and displays a diagram illustrating their relationships.

To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.

Usage

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

ahaversinf( x )

Computes the inverse half-value versed sine of a single-precision floating-point number.

var v = ahaversinf( 0.0 );
// returns 0.0

v = ahaversinf( 1.0 );
// returns ~3.1416

v = ahaversinf( 0.5 );
// returns ~1.5708

If x < 0, x > 1, or x is NaN, the function returns NaN.

var v = ahaversinf( 1.5 );
// returns NaN

v = ahaversinf( -3.14 );
// returns NaN

v = ahaversinf( NaN );
// returns NaN

Examples

var linspace = require( '@stdlib/array-base-linspace' );
var ahaversinf = require( '@stdlib/math-base-special-ahaversinf' );

var x = linspace( 0.0, 1.0, 100 );

var i;
for ( i = 0; i < x.length; i++ ) {
    console.log( ahaversinf( x[ i ] ) );
}

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C APIs

Usage

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

stdlib_base_ahaversinf( x )

Computes the inverse half-value versed sine of a single-precision floating-point number (in radians).

float out = stdlib_base_ahaversinf( 0.0f );
// returns 0.0f

If x < 0, x > 1, or x is NaN, the function returns NaN.

float out = stdlib_base_ahaversinf( -3.14f );
// returns NaN

The function accepts the following arguments:

• x: [in] float input value.

float stdlib_base_ahaversinf( const float x );

Examples

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

int main( void ) {
    const float x[] = { -2.0f, -1.6f, -1.2f, -0.8f, -0.4f, 0.4f, 0.8f, 1.2f, 1.6f, 2.0f };
    
    float v;
    int i;
    for ( i = 0; i < 10; i++ ) {
        v = stdlib_base_ahaversinf( x[ i ] );
        printf( "ahaversin(%f) = %f\n", x[ i ], v );
    }
}

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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.

Community

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License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.