以亂數進行某段日期區間的抽樣【延伸】
上一篇(以亂數進行某段日期區間的抽樣)談到如何隨機進行某段日期區間的抽樣，有網友提到筆者的範例程式碼只能輸入整數小時（例如08：00），為了提供更彈性的函數，筆者將GetRandomDate做了一個這樣的多型，程式碼如下：
1: /// <summary>
2: /// 亂數進行日期抽樣
3: /// </summary>
4: /// <param name="StartDate">起始日期</param>
5: /// <param name="DueDate">結束日期</param>
6: /// <param name="StartHour">每日起始時間(時)</param>
7: /// <param name="DueHour">每日結束時間(時)</param>
8: /// <param name="StartMinutes">每日起始時間(分)</param>
9: /// <param name="DueMinutes">每日結束時間(分)</param>
10: /// <param name="count">抽樣數量</param>
11: /// <returns></returns>
12: private static List<DateTime> GetRandomDate(DateTime StartDate, DateTime DueDate, int StartHour
13: ,int StartMinutes, int DueHour, int DueMinutes,int count)
14: {
15: List<DateTime> list = new List<DateTime>();
16: DateTime dtStart = StartDate.AddHours(StartHour).AddMinutes(StartMinutes);
17: DateTime dtDue = DueDate.AddHours(DueHour).AddMinutes(DueMinutes);
18:
19: if (!(dtStart.CompareTo(dtDue) > 0 || count < 0))
20: {
21: Random ran = new Random();
22: while (list.Count < count)
23: {
24: DateTime dtCurrent = dtStart.AddDays(ran.Next(0
25: , int.Parse(DueDate.Subtract(StartDate).TotalDays.ToString()) - 1));
26: dtCurrent = dtCurrent.AddMinutes(ran.Next(0, int.Parse(Math.Round(dtDue.Subtract(dtStart).TotalMinutes, 0).ToString()) - 1));
27:
28: DateTime dtLimitStart = new DateTime(dtCurrent.Year, dtCurrent.Month, dtCurrent.Day, StartHour, StartMinutes,0);
29: DateTime dtLimitEnd = new DateTime(dtCurrent.Year, dtCurrent.Month, dtCurrent.Day, DueHour, DueMinutes, 0);
30: if (dtCurrent.CompareTo(dtDue) < 1 && !list.Contains(dtCurrent)
31: && dtCurrent.CompareTo(dtLimitStart) >= 0 && dtCurrent.CompareTo(dtLimitEnd) <= 0)
32: {
33: list.Add(dtCurrent);
34: }
35: }
36: }
37: return list;
38: }
以下範例示範從2011/7/20 08:31至2011/07/30 12:05這段區間隨機抽樣出20個樣本：
1: List<DateTime> list = GetRandomDate(new DateTime(2011, 7, 20)
2: , new DateTime(2011, 7, 30)
3: , 8, 31, 12, 5, 20);
4: foreach (DateTime dt in list)
5: {
6: Console.WriteLine(dt.ToString("yy-MM-dd hh:mm"));
7: }
執行結果：
參考資料：