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 85 86 87 88 89 90 91 | 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 3x 3x 3x 3014x 3014x 3014x 9x 9x 3014x 1x 1x 3004x 3004x 3004x 3004x 3004x 3004x 3004x 3004x 3004x 3004x 3004x 3004x 3004x 3004x 3004x 3003x 3003x 3003x 1x 1x 3003x 1x 1x 3001x 3001x 3001x 3003x 3014x 3x 3x 3x 3x 3x | /**
* @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 constantFunction = require( '@stdlib/utils/constant-function' );
var degenerate = require( '@stdlib/stats/base/dists/degenerate/logpdf' ).factory;
var isnan = require( '@stdlib/math/base/assert/is-nan' );
var log1p = require( '@stdlib/math/base/special/log1p' );
var abs = require( '@stdlib/math/base/special/abs' );
var exp = require( '@stdlib/math/base/special/exp' );
var ln = require( '@stdlib/math/base/special/ln' );
var NINF = require( '@stdlib/constants/float64/ninf' );
// MAIN //
/**
* Returns a function for evaluating the logarithm of the probability density function (PDF) for a logistic distribution.
*
* @param {number} mu - location parameter
* @param {NonNegativeNumber} s - scale parameter
* @returns {Function} logPDF
*
* @example
* var logpdf = factory( 10.0, 2.0 );
* var y = logpdf( 10.0 );
* // returns ~-2.079
*
* y = logpdf( 5.0 );
* // returns ~-3.351
*/
function factory( mu, s ) {
var ls;
if ( isnan( mu ) || isnan( s ) || s < 0.0 ) {
return constantFunction( NaN );
}
if ( s === 0.0 ) {
return degenerate( mu );
}
ls = ln( s );
return logpdf;
/**
* Evaluates the logarithm of the probability density function (PDF) for a logistic distribution.
*
* @private
* @param {number} x - input value
* @returns {number} evaluated logPDF
*
* @example
* var y = logpdf( -1.2 );
* // returns <number>
*/
function logpdf( x ) {
var az;
var z;
if ( isnan( x ) ) {
return NaN;
}
if ( x === NINF ) {
return NINF;
}
z = ( x - mu ) / s;
az = -abs( z );
return az - (2.0 * log1p( exp( az ) )) - ls;
}
}
// EXPORTS //
module.exports = factory;
|