首页 > 解决方案 > Transmute 有效,但 mutate 无效

问题描述

我有下面的数据集以及此处未显示的其他列:

  v0102      v0103      child.below14 child.above14
1 31000010   1                      0             0
2 31000010   1                      0             0
3 31000010   1                      1             0
4 31000010   1                      1             0
5 31605621   1                      0             0
6 31605621   1                      1             0
7 31605621   1                      1             0
8 31605877   1                      0             0
9 31605877   1                      1             0

我想按前两列分组并计算 14 岁以下和以上儿童的数量。当我尝试使用 transmute 时,我得到了预期的答案:

df.pnad.mg %>% group_by(v0102, v0103) %>% transmute(children.below14 = sum(child.below14), children.above14 = sum(child.above14))

   v0102      v0103      children.below14 children.above14
 1 31000010   1                         3                0
 2 31000010   1                         3                0
 3 31000010   1                         3                0
 4 31000010   1                         3                0
 5 31605621   1                         2                0
 6 31605621   1                         2                0
 7 31605621   1                         2                0
 8 31605621   1                         2                0
 9 31605877   1                         1                0

但是,当我从 transmute 切换到 mutate 时,输出似乎忽略了 group_by() 动词:

df.pnad.mg %>% group_by(v0102, v0103) %>% mutate(children.below14 = sum(child.below14), children.above14 = sum(child.above14))

  v0102      v0103      children.below14 children.above14
1 31000010   1                      8092             7949
2 31000010   1                      8092             7949
3 31000010   1                      8092             7949
4 31000010   1                      8092             7949
5 31000010   1                      8092             7949
6 31605621   1                      8092             7949
7 31605621   1                      8092             7949
8 31605621   1                      8092             7949
9 31605877   1                      8092             7949

我错过了什么吗?

标签: rdplyr

解决方案


你想要的功能summarize不是mutate

df.pnad.mg %>% 
  group_by(v0102, v0103) %>% 
  summarize(children.below14 = sum(child.below14), 
            children.above14 = sum(child.above14))

当您使用mutate它时,它会计算总和,但它会保留所有行。

使用九行数据,这是我得到的输出:

`summarise()` regrouping output by 'v0102' (override with `.groups` argument)
# A tibble: 3 x 4
# Groups:   v0102 [3]
     v0102 v0103 children.below14 children.above14
     <dbl> <dbl>            <dbl>            <dbl>
1 31000010     1                2                0
2 31605621     1                2                0
3 31605877     1                1                0

如果您希望保留所有行,那么mutate应该可以。我无法在dplyr 1.0.2. 这是我的输出mutate

df.pnad.mg %>% 
  group_by(v0102, v0103) %>% 
  mutate(children.below14 = sum(child.below14), 
         children.above14 = sum(child.above14))
# A tibble: 9 x 6
# Groups:   v0102, v0103 [3]
     v0102 v0103 child.below14 child.above14 children.below14 children.above14
     <dbl> <dbl>         <dbl>         <dbl>            <dbl>            <dbl>
1 31000010     1             0             0                2                0
2 31000010     1             0             0                2                0
3 31000010     1             1             0                2                0
4 31000010     1             1             0                2                0
5 31605621     1             0             0                2                0
6 31605621     1             1             0                2                0
7 31605621     1             1             0                2                0
8 31605877     1             0             0                1                0
9 31605877     1             1             0                1                0

如果您想创建这些新列并删除旧列,那么transmute您就是这样做的。


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