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4ca88ae2d6
* refactor + countdifficultstrain * norm in utils * adjust scaling shift * fix comment * revert all value changes * add the else back * remove cds comments
60 lines
2.9 KiB
C#
60 lines
2.9 KiB
C#
// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
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// See the LICENCE file in the repository root for full licence text.
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using System;
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using System.Linq;
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namespace osu.Game.Rulesets.Difficulty.Utils
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{
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public static class DifficultyCalculationUtils
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{
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/// <summary>
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/// Converts BPM value into milliseconds
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/// </summary>
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/// <param name="bpm">Beats per minute</param>
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/// <param name="delimiter">Which rhythm delimiter to use, default is 1/4</param>
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/// <returns>BPM conveted to milliseconds</returns>
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public static double BPMToMilliseconds(double bpm, int delimiter = 4)
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{
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return 60000.0 / delimiter / bpm;
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}
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/// <summary>
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/// Converts milliseconds value into a BPM value
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/// </summary>
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/// <param name="ms">Milliseconds</param>
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/// <param name="delimiter">Which rhythm delimiter to use, default is 1/4</param>
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/// <returns>Milliseconds conveted to beats per minute</returns>
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public static double MillisecondsToBPM(double ms, int delimiter = 4)
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{
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return 60000.0 / (ms * delimiter);
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}
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/// <summary>
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/// Calculates a S-shaped logistic function (https://en.wikipedia.org/wiki/Logistic_function)
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/// </summary>
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/// <param name="x">Value to calculate the function for</param>
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/// <param name="maxValue">Maximum value returnable by the function</param>
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/// <param name="multiplier">Growth rate of the function</param>
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/// <param name="midpointOffset">How much the function midpoint is offset from zero <paramref name="x"/></param>
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/// <returns>The output of logistic function of <paramref name="x"/></returns>
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public static double Logistic(double x, double midpointOffset, double multiplier, double maxValue = 1) => maxValue / (1 + Math.Exp(multiplier * (midpointOffset - x)));
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/// <summary>
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/// Calculates a S-shaped logistic function (https://en.wikipedia.org/wiki/Logistic_function)
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/// </summary>
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/// <param name="maxValue">Maximum value returnable by the function</param>
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/// <param name="exponent">Exponent</param>
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/// <returns>The output of logistic function</returns>
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public static double Logistic(double exponent, double maxValue = 1) => maxValue / (1 + Math.Exp(exponent));
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/// <summary>
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/// Returns the <i>p</i>-norm of an <i>n</i>-dimensional vector (https://en.wikipedia.org/wiki/Norm_(mathematics))
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/// </summary>
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/// <param name="p">The value of <i>p</i> to calculate the norm for.</param>
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/// <param name="values">The coefficients of the vector.</param>
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/// <returns>The <i>p</i>-norm of the vector.</returns>
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public static double Norm(double p, params double[] values) => Math.Pow(values.Sum(x => Math.Pow(x, p)), 1 / p);
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}
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}
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