Arcvercosine

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

The inverse versed cosine is defined as

Usage

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

avercosf( x )

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

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

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

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

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

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

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

v = avercosf( NaN );
// returns NaN

Examples

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

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

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

C APIs

Usage

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

stdlib_base_avercosf( x )

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

float out = stdlib_base_avercosf( -3.141592653589793f / 2.0f );
// returns ~2.1783f

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

float out = stdlib_base_avercosf( -3.141592653589793f );
// returns NaN

The function accepts the following arguments:

x: [in] float input value.

float stdlib_base_avercosf( const float x );

Examples

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

int main( void ) {
    const float x[] = { -2.5f, -2.0f, -1.5f, -1.0f, -0.5f, 0.5f, 1.0f, 1.5f, 2.0f, 2.5f };
    
    float v;
    int i;
    for ( i = 0; i < 10; i++ ) {
        v = stdlib_base_avercosf( x[ i ] );
        printf( "avercosf(%f) = %f\n", x[ i ], v );
    }
}