相关疑难解决方法(0)

我有两个数据帧(df和df1).df1是df的子集.我想获得一个数据帧,它是df中df1的补码,即返回第一个数据集的行,这些行在第二个数据集中不匹配.比如让,

数据框df:

heads
row1
row2
row3
row4
row5

数据框df1:

heads
row3
row5

然后所需的输出df2是:

heads
row1
row2
row4

tidyr::complete()将行添加到a data.frame中,以获取数据中缺少的列值组合.例:

library(dplyr)
library(tidyr)

df <- data.frame(person = c(1,2,2),
                 observation_id = c(1,1,2),
                 value = c(1,1,1))
df %>%
  tidyr::complete(person,
                  observation_id,
                  fill = list(value=0))

产量

# A tibble: 4 × 3
  person observation_id value
   <dbl>          <dbl> <dbl>
1      1              1     1
2      1              2     0
3      2              1     1
4      2              2     1

其中value组合person == 1和observation_id == 2缺少的组合df已填入值0.

什么相当于这个data.table？

我有以下data.table,我不能使用dput命令的输出来重新创建它:

> ddt
   Unit Anything index new
1:    A      3.4     1   1
2:    A      6.9     2   1
3:   A1      1.1     1   2
4:   A1      2.2     2   2
5:    B      2.0     1   3
6:    B      3.0     2   3
> 
> 
> str(ddt)
Classes ‘data.table’ and 'data.frame':  6 obs. of  4 variables:
 $ Unit    : Factor w/ 3 levels "A","A1","B": 1 1 2 2 3 3
 $ Anything: num  3.4 6.9 1.1 2.2 2 3
 $ index   : num  1 2 1 …