@stdlib/math-base-special-avercos NPM

Arcvercosine

$NPM version$ $Build Status$ $Coverage Status$

Compute the inverse versed cosine.

Installation

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

Usage

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

avercos( x )

Computes the inverse versed cosine.

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

v = avercos( -3.141592653589793/2.0 );
// returns ~2.1783

v = avercos( -3.141592653589793/6.0 );
// returns ~1.0742

If x < -2, x > 0, or x is NaN, the function returns NaN.

var v = avercos( 1.0 );
// returns NaN

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

v = avercos( NaN );
// returns NaN

Examples

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

var x = linspace( -2.0, 0.0, 100 );

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

C APIs

Usage

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

stdlib_base_avercos( x )

Compute the inverse versed cosine of a double-precision floating-point number (in radians).

double out = stdlib_base_avercos( -3.141592653589793/2.0 );
// returns ~2.1783

If x < -2, x > 0, or x is NaN, the function returns NaN.

double out = stdlib_base_avercos( -3.141592653589793 );
// returns NaN

The function accepts the following arguments:

x: [in] double input value.

double stdlib_base_avercos( const double x );

Examples

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

int main( void ) {
    const double x[] = { -2.5, -2.0, -1.5, -1.0, -0.5, 0.5, 1.0, 1.5, 2.0, 2.5 };
    
    double v;
    int i;
    for ( i = 0; i < 10; i++ ) {
        v = stdlib_base_avercos( x[ i ] );
        printf( "avercos(%lf) = %lf\n", x[ i ], 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.