Question

所以我有一个看起来像这样但没有周末的数据集：

 X1          X2
3798 2009-12-29           0
3799 2009-12-30           0
3800 2009-12-31           0 
3802 2010-01-02           0
3803 2010-01-03         2.1
3804 2010-01-04           0
3805 2010-01-05           0
3806 2010-01-06           0
3807 2010-01-07           0
3808 2010-01-08           0
3809 2010-01-09           0
3810 2010-01-10         6.8
3811 2010-01-12           0
3812 2010-01-13           0
3813 2010-01-14        17.7
3814 2010-01-16           0
3815 2010-01-17           0
3816 2010-01-18         1.5
3817 2010-01-19           0
3818 2010-01-20           0
3819 2010-01-21           0
3820 2010-01-22           0
3821 2010-01-23           0
3822 2010-01-24           0
3823 2010-01-25           0
3824 2010-01-26           0
3825 2010-01-27         4.5
3826 2010-01-28           0
3827 2010-01-29           0
3828 2010-01-31           0
3829 2010-02-01           0
3830 2010-02-03           0
3831 2010-02-04           0
3832 2010-02-05           0
3833 2010-02-07           0
3834 2010-02-08           0
3835 2010-02-09         1.2

我希望在每个月的第15天左右获得5天的平均值，如果第15次发生在周末并且数据集中不存在，我想要在5天左右平均最近的日期（第14或第16），这可能吗？

所以这是预期的输出

 X1          X2         5-day average
 1         2009-12-14           2
 2         2010-01-15           3 
 3         2010-02-15           4
 4         2010-03-16           2 
 5         2010-04-15           1
 6         2010-05-14           7

Answer 1

使用rollapply中的zoo函数获取滚动平均值非常容易。然后你可以提取你需要的那些（即每个月的15号左右）。

# packages used
require(data.table)
require(zoo)
# data preparation
df <- read.table(text=' X1          X2
                 3798 2009-12-29           0
                 3799 2009-12-30           0
                 3800 2009-12-31           0 
                 3802 2010-01-02           0
                 3803 2010-01-03         2.1
                 3804 2010-01-04           0
                 3805 2010-01-05           0
                 3806 2010-01-06           0
                 3807 2010-01-07           0
                 3808 2010-01-08           0
                 3809 2010-01-09           0
                 3810 2010-01-10         6.8
                 3811 2010-01-12           0
                 3812 2010-01-13           0
                 3813 2010-01-14        17.7
                 3814 2010-01-16           0
                 3815 2010-01-17           0
                 3816 2010-01-18         1.5
                 3817 2010-01-19           0
                 3818 2010-01-20           0
                 3819 2010-01-21           0
                 3820 2010-01-22           0
                 3821 2010-01-23           0
                 3822 2010-01-24           0
                 3823 2010-01-25           0
                 3824 2010-01-26           0
                 3825 2010-01-27         4.5
                 3826 2010-01-28           0
                 3827 2010-01-29           0
                 3828 2010-01-31           0
                 3829 2010-02-01           0
                 3830 2010-02-03           0
                 3831 2010-02-04           0
                 3832 2010-02-05           0
                 3833 2010-02-07           0
                 3834 2010-02-08           0
                 3835 2010-02-09         1.2', header=TRUE)
setDT(df)
df[, X1 <- as.Date(X1)]
setkey(df, X1)
# taking rolling averages
df[, rmean:=rollapply(X2, 5, mean, fill=NA)]
# extracting the rolling averages you need
dt <- df[, list(day15=abs(mday(X1)-15) == min(abs(mday(X1)-15)), X1, rmean), by=list(year(X1), month(X1))]
dt[day15==TRUE]
dt[day15==TRUE, .SD[1,] ,by=list(month, year)]

如何在r的特定日期周围取5天的平均值

1 个答案: