Question

我们有一个包含2列的数据框，如下所示：这是一个月份列表，其中包含值和分配的季度。

quarter_number base_quarter 
1            63.44767
1            71.12924
1            95.58290
2            56.85544
2            45.89876
2            47.88994
3            65.54654
...

该季度的数字重复3次，然后获得+1。目的是为四分之一的第二个和第三个月的每个值设置与第一个相同的值。所以它看起来像这样：

quarter_number base_quarter 
1            63.44767
1            63.44767
1            63.44767
2            56.85544
2            56.85544
...

感谢您的提示！

Answer 1

使用ave：

R> set.seed(1)
R> Data <- data.frame(quarter_number=rep(1:3, each=3), base_quarter=10*rnorm(9))
R> Data
  quarter_number base_quarter
1              1    -6.264538
2              1     1.836433
3              1    -8.356286
4              2    15.952808
5              2     3.295078
6              2    -8.204684
7              3     4.874291
8              3     7.383247
9              3     5.757814
R> head1 <- function(x) head(x,1)
R> Data$base_quarter <- ave(Data$base_quarter, Data$quarter_number, FUN=head1)
R> Data
  quarter_number base_quarter
1              1    -6.264538
2              1    -6.264538
3              1    -6.264538
4              2    15.952808
5              2    15.952808
6              2    15.952808
7              3     4.874291
8              3     4.874291
9              3     4.874291

Answer 2

我的第二个Joran和Andrie最好用您的代码发布可重现的数据。这是我的方法，这个问题

set.seed(1)
Dat <- data.frame(number = rep(1:10, each =3), value = rnorm(30))
head(Dat)

  number    value
1      1 -0.62645
2      1  0.18364
3      1 -0.83563
4      2  1.59528
5      2  0.32951
6      2 -0.82047


require(plyr) # for join
join(number = unique(Dat$number)), Dat, match = "first")
Joining by: number
   number     value
1       1 -0.626454
2       2  1.595281
3       3  0.487429
4       4 -0.305388
5       5 -0.621241
6       6 -0.044934
7       7  0.821221
8       8  0.782136
9       9  0.619826
10     10 -1.470752

Dat2 <- join(data.frame(number = unique(Dat$number)), Dat, match = "first")
Result <- Dat2[rep(1:nrow(Dat2), each = 3), ]
head(Result)    

    number    value
1        1 -0.62645
1.1      1 -0.62645
1.2      1 -0.62645
2        2  1.59528
2.1      2  1.59528
2.2      2  1.59528

希望这个帮助

Answer 3

这里有几个不错的答案。这是另一种方式：

Data <- data.frame(quarter_number=rep(1:3, each=3), base_quarter=10*rnorm(9))
merge(Data, Data[! duplicated(Data$quarter_number), ], 
      by='quarter_number', suffix=c('.orig', '.first'))

R：将列表的第二个和第三个值设置为第一个值

3 个答案: