資料結構
網路
RDBMS
作業系統
Java
MS Excel
iOS
HTML
CSS
Android
Python
C 程式設計
C++
C#
MongoDB
MySQL
Javascript
PHP
物理
化學
生物
數學
英語
經濟
心理學
社會研究
時尚研究
法律研究如何在 R 中查詢兩個日期之間的天數和週數？
在資料分析中，時間序列是我們必須處理的常見資料型別之一，它可能包含日期資料以及其他變數。我們可能希望查詢兩個時間之間的差異，以檢查有多少天或周的時間序列發生了變化。這可以透過 difftime 函式輕鬆完成。
示例
> difftime(strptime("25/07/2021", format = "%d/%m/%Y"),
+ strptime("25/07/2020", format = "%d/%m/%Y"),units="weeks")
Time difference of 52.14286 weeks
> difftime(strptime("25.07.2021", format = "%d.%m.%Y"),
+ strptime("25.07.2020", format = "%d.%m.%Y"),units="weeks")
Time difference of 52.14286 weeks
> difftime(strptime("25.07.2021", format = "%d.%m.%Y"),
+ strptime("25.07.2020", format = "%d.%m.%Y"))
Time difference of 365 days
> difftime(strptime("01.01.2021", format = "%d.%m.%Y"),
+ strptime("25.07.2020", format = "%d.%m.%Y"))
Time difference of 160 days
> difftime(strptime("01.01.2021", format = "%d.%m.%Y"),
+ strptime("25.07.2020", format = "%d.%m.%Y"),units="weeks")
Time difference of 22.85714 weeks
> difftime(strptime("01.01.2050", format = "%d.%m.%Y"),
+ strptime("01.01.2020", format = "%d.%m.%Y"))
Time difference of 10958 days
> difftime(strptime("01.01.2050", format = "%d.%m.%Y"),
+ strptime("01.01.2020", format = "%d.%m.%Y"),units="weeks")
Time difference of 1565.429 weeks
> difftime(strptime("01.01.2030", format = "%d.%m.%Y"),
+ strptime("01.01.2020", format = "%d.%m.%Y"),units="weeks")
Time difference of 521.8571 weeks
> difftime(strptime("01.01.2030", format = "%d.%m.%Y"),
+ strptime("01.01.2020", format = "%d.%m.%Y"))
Time difference of 3653 days
> difftime(strptime("25/12/2021", format = "%d/%m/%Y"),
+ strptime("01/01/2021", format = "%d/%m/%Y"),units="weeks")
Time difference of 51.14286 weeks
> difftime(strptime("25/12/2021", format = "%d/%m/%Y"),
+ strptime("01/01/2021", format = "%d/%m/%Y"))
Time difference of 358 days
> difftime(strptime("01/01/3000", format = "%d/%m/%Y"),
+ strptime("01/01/2000", format = "%d/%m/%Y"))
Time difference of 365243 days
> difftime(strptime("01/01/3000", format = "%d/%m/%Y"),
+ strptime("01/01/2000", format = "%d/%m/%Y"),units="weeks")
Time difference of 52177.57 weeks
> difftime(strptime("01/01/0001", format = "%d/%m/%Y"),
+ strptime("25/07/2020", format = "%d/%m/%Y"))
Time difference of -737630 days
> difftime(strptime("01/01/0001", format = "%d/%m/%Y"),
+ strptime("25/07/2020", format = "%d/%m/%Y"),units="weeks")
Time difference of -105375.7 weeks
更新於：2020 年 8 月 11 日
294 次瀏覽
廣告