Archaversine

Compute the inverse half-value versed sine.

The inverse half-value versed sine is defined as

a h a v e r s i n left-parenthesis theta right-parenthesis equals 2 dot arc sine left-parenthesis StartRoot theta EndRoot right-parenthesis

Usage

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

ahaversin( x )

Computes the inverse half-value versed sine.

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

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

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

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

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

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

v = ahaversin( NaN );
// returns NaN

Examples

var linspace = require( '@stdlib/math/utils/linspace' );
var ahaversin = require( '@stdlib/math/base/special/ahaversin' );

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

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