Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 | 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 28203x 28203x 28203x 28203x 28203x 28203x 14099x 14099x 14099x 14099x 14104x 28203x 1x 1x 1x 1x 1x | /**
* @license Apache-2.0
*
* Copyright (c) 2018 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
'use strict';
// MODULES //
var sin = require( '@stdlib/math/base/special/sin' );
var cos = require( '@stdlib/math/base/special/cos' );
// MAIN //
/**
* Computes the half-value coversed cosine.
*
* @param {number} x - input value (in radians)
* @returns {number} half-value coversed cosine
*
* @example
* var v = hacovercos( 0.0 );
* // returns 0.5
*
* @example
* var v = hacovercos( 3.141592653589793/2.0 );
* // returns 1.0
*
* @example
* var v = hacovercos( -3.141592653589793/6.0 );
* // returns 0.25
*
* @example
* var v = hacovercos( NaN );
* // returns NaN
*/
function hacovercos( x ) {
var s;
var c;
s = sin( x );
if ( s < 0.0 ) {
// Where `sin(x)` is close to minus one, `1 + sin(x)` cancels. Use `1 + sin(x) = cos(x)^2 / (1 - sin(x))` where `sin(x) < 0`, since `cos(x)` is computed with full relative accuracy near its zeros and the denominator does not cancel:
c = cos( x );
return ( c * c ) / ( 2.0 * ( 1.0 - s ) );
}
return ( 1.0 + s ) / 2.0;
}
// EXPORTS //
module.exports = hacovercos;
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