UNPKG

@stdlib/stats-base-dists-arcsine-pdf

Version:

Arcsine distribution probability density function (PDF).

119 lines (109 loc) 2.64 kB
/* * @license Apache-2.0 * * Copyright (c) 2019 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. */ // TypeScript Version: 4.1 /** * Evaluates the probability density function (PDF) for an arcsine distribution. * * @param x - input value * @returns evaluated PDF */ type Unary = ( x: number ) => number; /** * Interface for the probability density function (PDF) of an arcsine distribution. */ interface PDF { /** * Evaluates the probability density function (PDF) for an arcsine distribution with minimum support `a` and maximum support `b` at a value `x`. * * ## Notes * * - If provided `a >= b`, the function returns `NaN`. * * @param x - input value * @param a - minimum support * @param b - maximum support * @returns evaluated PDF * * @example * var y = pdf( 2.0, 0.0, 4.0 ); * // returns ~0.159 * * @example * var y = pdf( 5.0, 0.0, 4.0 ); * // returns 0.0 * * @example * var y = pdf( 0.25, 0.0, 1.0 ); * // returns ~0.735 * * @example * var y = pdf( NaN, 0.0, 1.0 ); * // returns NaN * * @example * var y = pdf( 0.0, NaN, 1.0 ); * // returns NaN * * @example * var y = pdf( 0.0, 0.0, NaN ); * // returns NaN * * @example * var y = pdf( 2.0, 3.0, 1.0 ); * // returns NaN */ ( x: number, a: number, b: number ): number; /** * Returns a function for evaluating the probability density function (PDF) for an arcsine distribution with minimum support `a` and maximum support `b`. * * @param a - minimum support * @param b - maximum support * @returns PDF * * @example * var mypdf = pdf.factory( 0.0, 10.0 ); * var y = mypdf( 2.0 ); * // returns ~0.08 * * y = mypdf( 12.0 ); * // returns 0.0 */ factory( a: number, b: number ): Unary; } /** * Arcsine distribution probability density function (PDF). * * @param x - input value * @param a - minimum support * @param b - maximum support * @returns evaluated PDF * * @example * var y = pdf( 3.0, 2.0, 6.0 ); * // returns ~0.184 * * var mypdf = pdf.factory( 6.0, 7.0 ); * y = mypdf( 7.0 ); * // returns Infinity * * y = mypdf( 5.0 ); * // returns 0.0 */ declare var pdf: PDF; // EXPORTS // export = pdf;