using Apewer.Internals; using System; using System.Collections.Generic; using System.Runtime.InteropServices; using System.Text; namespace Apewer { /// <summary>数值实用工具。</summary> public static class NumberUtility { #region 随机数。 /// <summary>用于生成随机数的时钟位置。</summary> private static int RandomSeed = 327680; private static float RandomTimer() { var now = DateTime.Now; return (float)((double)(checked((60 * now.Hour + now.Minute) * 60 + now.Second)) + (double)now.Millisecond / 1000.0); } private static void RandomInit() { float timer = RandomTimer(); int num1 = RandomSeed; int num2 = BitConverter.ToInt32(BitConverter.GetBytes(timer), 0); num2 = ((num2 & 65535) ^ num2 >> 16) << 8; num1 = ((num1 & -16776961) | num2); RandomSeed = num1; } /// <summary>生成不大于 1 的随机数,最小为 0。</summary> public static float RandomFloat(float max = 1F) { RandomInit(); int num1 = RandomSeed; if ((double)max != 0.0) { if ((double)max < 0.0) { num1 = BitConverter.ToInt32(BitConverter.GetBytes(max), 0); long vnum2 = (long)num1; vnum2 &= unchecked((long)((ulong)-1)); num1 = checked((int)(vnum2 + (vnum2 >> 24) & 16777215L)); } num1 = checked((int)(unchecked((long)num1) * 1140671485L + 12820163L & 16777215L)); } RandomSeed = num1; return (float)num1 / 16777216f; } /// <summary>生成随机整数,包含最小值和最大值。</summary> /// <param name="min">最小值。</param> /// <param name="max">最大值。</param> /// <returns></returns> public static int RandomInteger(int max, int min = 0) { if (max < min) { var temp = max; max = min; min = temp; } float rate = (max - min + 1) * RandomFloat(); int result = min + (int)rate; return result; } #endregion #region Restrict 约束值范围。 /// <summary>约束值范围,若源值不在范围中,则修改为接近的值。</summary> public static T RestrictValue<T>(T origin, T min, T max) where T : IComparable { try { if (min.CompareTo(max) > 0) return origin; if (origin.CompareTo(min) < 0) return min; if (origin.CompareTo(max) > 0) return max; return origin; } catch { } return origin; } /// <summary>约束值范围,若源值不在范围中,则修改为接近的值。</summary> public static Byte RestrictValue(Byte target, Byte min, Byte max) { return RestrictValue<Byte>(target, min, max); } /// <summary>约束值范围,若源值不在范围中,则修改为接近的值。</summary> public static Int16 RestrictValue(Int16 target, Int16 min, Int16 max) { return RestrictValue<Int16>(target, min, max); } /// <summary>约束值范围,若源值不在范围中,则修改为接近的值。</summary> public static Int32 RestrictValue(Int32 target, Int32 min, Int32 max) { return RestrictValue<Int32>(target, min, max); } /// <summary>约束值范围,若源值不在范围中,则修改为接近的值。</summary> public static Int64 RestrictValue(Int64 target, Int64 min, Int64 max) { return RestrictValue<Int64>(target, min, max); } /// <summary>约束值范围,若源值不在范围中,则修改为接近的值。</summary> public static Single RestrictValue(Single target, Single min, Single max) { return RestrictValue<Single>(target, min, max); } /// <summary>约束值范围,若源值不在范围中,则修改为接近的值。</summary> public static Double RestrictValue(Double target, Double min, Double max) { return RestrictValue<Double>(target, min, max); } /// <summary>约束值范围,若源值不在范围中,则修改为接近的值。</summary> public static Decimal RestrictValue(Decimal target, Decimal min, Decimal max) { return RestrictValue<Decimal>(target, min, max); } #endregion /// <summary>平均值。</summary> public static double Average(params double[] values) { var amount = 0d; foreach (var i in values) amount += i; return amount / Convert.ToDouble(values.Length); } #region 最小值、最大值。 private static T GetMost<T>(Func<T, T, bool> replace, T[] values) { if (values == null) return default; var length = values.LongLength; if (length == 0L) return default; if (length == 1L) return values[0L]; var most = values[0]; for (var i = 1L; i < length; i++) { var value = values[i]; if (value == null) continue; if (most == null) { most = value; } else { var doReplace = replace(most, value); if (doReplace) most = value; } } return most; } // 无法输出正确结果。 // public static T GetMin<T>(params IComparable[] values) // { // var result = GetMost((a, b) => a.CompareTo(b) == 1, values); // return result == null ? default : (T)result; // } // 无法输出正确结果。 // public static T GetMin<T>(params IComparable<T>[] values) // { // var result = GetMost((a, b) => a.CompareTo((T)b) == 1, values); // return result == null ? default : (T)result; // } // 无法输出正确结果。 // public static T GetMax<T>(params IComparable[] values) // { // var result = GetMost((a, b) => a.CompareTo(b) == -1, values); // return result == null ? default : (T)result; // } // 无法输出正确结果。 // public static T GetMax<T>(params IComparable<T>[] values) // { // var result = GetMost((a, b) => a.CompareTo((T)b) == -1, values); // return result == null ? default : (T)result; // } /// <summary>最小值。</summary> public static byte Min(params byte[] values) => GetMost((a, b) => a > b, values); /// <summary>最小值。</summary> public static int Min(params int[] values) => GetMost((a, b) => a > b, values); /// <summary>最小值。</summary> public static long Min(params long[] values) => GetMost((a, b) => a > b, values); /// <summary>最小值。</summary> public static float Min(params float[] values) => GetMost((a, b) => a > b, values); /// <summary>最小值。</summary> public static double Min(params double[] values) => GetMost((a, b) => a > b, values); /// <summary>最小值。</summary> public static decimal Min(params decimal[] values) => GetMost((a, b) => a > b, values); /// <summary>最大值。</summary> public static byte Max(params byte[] values) => GetMost((a, b) => a < b, values); /// <summary>最大值。</summary> public static int Max(params int[] values) => GetMost((a, b) => a < b, values); /// <summary>最大值。</summary> public static long Max(params long[] values) => GetMost((a, b) => a < b, values); /// <summary>最大值。</summary> public static float Max(params float[] values) => GetMost((a, b) => a < b, values); /// <summary>最大值。</summary> public static double Max(params double[] values) => GetMost((a, b) => a < b, values); /// <summary>最大值。</summary> public static decimal Max(params decimal[] values) => GetMost((a, b) => a < b, values); #endregion /// <summary>Pearson Correlation Coefficient 皮尔逊相关系数。计算两个数组的相似度。数组长度不相等时,以 0 填充不足的长度。</summary> /// <remarks> /// <para>0.8 ~ 1.0 : 极强相关</para> /// <para>0.6 ~ 0.8 : 强相关</para> /// <para>0.4 ~ 0.6 : 中等程度相关</para> /// <para>0.2 ~ 0.4 : 弱相关</para> /// <para>0.0 ~ 0.2 : 极弱相关或无相关</para> /// </remarks> /// <exception cref="ArgumentException"></exception> public static double Pearson(double[] bytes1, double[] bytes2) { var length1 = bytes1 == null ? 0L : bytes1.LongLength; var length2 = bytes2 == null ? 0L : bytes2.LongLength; var length = Math.Max(length1, length2); if (length < 1) return 1D; var x = new double[length]; var y = new double[length]; for (var i = 0L; i < length; i++) { if (i < length1) x[i] = bytes1[i]; if (i < length2) y[i] = bytes2[i]; } int n = x.Length; // 数组长度。 double s = 0d; // 分子。 double m1 = 0d, m2 = 0d; // 分母。 double xa = Average(x); double ya = Average(y); for (int i = 0; i < n; i++) { s += (x[i] - xa) * (y[i] - ya); m1 += Math.Pow(x[i] - xa, 2); m2 += Math.Pow(y[i] - ya, 2); } double r = s / (Math.Sqrt(m1) * Math.Sqrt(m2)); return r; } } }