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 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 | 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 3x 1006x 1006x 1006x 2x 2x 1006x 1x 1x 1003x 1003x 1003x 1003x 1003x 1003x 1003x 1003x 1003x 1003x 1003x 1003x 1003x 1003x 1003x 1004x 3x 3x 1004x 1x 1x 1000x 1004x 1006x 3x 3x 3x 3x 3x | /**
* @license Apache-2.0
*
* Copyright (c) 2026 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 constantFunction = require( '@stdlib/utils/constant-function' );
var degenerate = require( '@stdlib/stats/base/dists/degenerate/quantile' ).factory;
var isnan = require( '@stdlib/math/base/assert/is-nan' );
var erfinv = require( '@stdlib/math/base/special/erfinv' );
var SQRT2 = require( '@stdlib/constants/float64/sqrt-two' );
var PINF = require( '@stdlib/constants/float64/pinf' );
// MAIN //
/**
* Returns a function for evaluating the quantile function for a Half-normal distribution with scale parameter `sigma`.
*
* @param {NonNegativeNumber} sigma - scale parameter
* @returns {Function} quantile function
*
* @example
* var myquantile = factory( 1.0 );
* var y = myquantile( 0.2 );
* // returns ~0.253
*
* y = myquantile( 0.8 );
* // returns ~1.282
*/
function factory( sigma ) {
var C;
if ( isnan( sigma ) || sigma < 0.0 ) {
return constantFunction( NaN );
}
if ( sigma === 0.0 ) {
return degenerate( 0.0 );
}
C = sigma * SQRT2;
return quantile;
/**
* Evaluates the quantile function for a Half-normal distribution.
*
* @private
* @param {Probability} p - cumulative probability
* @returns {number} evaluated quantile function
*
* @example
* var y = quantile( 0.3 );
* // returns <number>
*/
function quantile( p ) {
if ( isnan( p ) || p < 0.0 || p > 1.0 ) {
return NaN;
}
if ( p === 1.0 ) {
return PINF;
}
return C * erfinv( p );
}
}
// EXPORTS //
module.exports = factory;
|