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 92 93 94 95 96 97 98 99 100 101 102 103 | 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 4019x 4019x 4019x 4019x 4019x 4019x 4019x 4012x 4019x 8x 8x 4019x 8x 8x 4003x 4003x 4003x 4003x 4003x 4003x 4003x 4003x 4003x 4003x 4003x 4003x 4003x 4003x 4003x 4003x 4003x 4003x 1x 1x 4003x 1x 1x 4001x 4003x 1000x 1000x 3001x 4003x 3000x 3000x 1x 1x 4003x 4019x 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 isnan = require( '@stdlib/math/base/assert/is-nan' );
var pow = require( '@stdlib/math/base/special/pow' );
var ln = require( '@stdlib/math/base/special/ln' );
var log1p = require( '@stdlib/math/base/special/log1p' );
var NINF = require( '@stdlib/constants/float64/ninf' );
// MAIN //
/**
* Returns a function for evaluating the natural logarithm of the cumulative distribution function (CDF) for a triangular distribution with lower limit `a` and upper limit `b` and mode `c`.
*
* @param {number} a - lower limit
* @param {number} b - upper limit
* @param {number} c - mode
* @returns {Function} logCDF
*
* @example
* var logcdf = factory( 0.0, 10.0, 2.0 );
* var y = logcdf( 0.5 );
* // returns ~-4.382
*
* y = logcdf( 8.0 );
* // returns ~-0.051
*/
function factory( a, b, c ) {
var denom1;
var denom2;
if (
isnan( a ) ||
isnan( b ) ||
isnan( c )
) {
return constantFunction( NaN );
}
if ( !( a <= c && c <= b ) ) {
return constantFunction( NaN );
}
denom1 = ( b - a ) * ( c - a );
denom2 = ( b - a ) * ( b - c );
return logcdf;
/**
* Evaluates the natural logarithm of the cumulative distribution function (CDF) for a triangular distribution.
*
* @private
* @param {number} x - input value
* @returns {number} evaluated logCDF
*
* @example
* var y = logcdf( 2.0 );
* // returns <number>
*/
function logcdf( x ) {
if ( isnan( x ) ) {
return NaN;
}
if ( x <= a ) {
return NINF;
}
// Case: x > a
if ( x <= c ) {
return ( 2.0 * ln( x - a ) ) - ln( denom1 );
}
// Case: x > c
if ( x < b ) {
return log1p( -pow( b - x, 2.0 ) / denom2 );
}
// Case: x >= b
return 0.0;
}
}
// EXPORTS //
module.exports = factory;
|