Question

我的数据集如下

dput(data2)
structure(list(School = structure(c(1L, 1L, 1L, 2L, 2L, 2L, 3L, 
3L, 3L), .Label = c("School1", "School2", "School3"), class = "factor"), 
    Year = c(2015L, 2014L, 2013L, 2015L, 2014L, 2013L, 2015L, 
    2014L, 2013L), Rate = c(70L, 50L, 30L, 80L, 90L, 11L, 60L, 
    50L, 40L)), .Names = c("School", "Year", "Rate"), class = "data.frame", row.names = c(NA, 
-9L))


   School Year Rate
1 School1 2015   70
2 School1 2014   50
3 School1 2013   30
4 School2 2015   80
5 School2 2014   90
6 School2 2013   11
7 School3 2015   60
8 School3 2014   50
9 School3 2013   40

我正在尝试做的是产生一个输出，其中数据按列学校分组，学校的顺序按照2015年的降序排列。

所以输出应该像

   School Year Rate
1 School2 2015   80
2 School2 2014   90
3 School2 2013   11
4 School1 2015   70
5 School1 2014   50
6 School1 2013   30
7 School3 2015   60
8 School3 2014   50
9 School3 2013   40

使用我的示例中的数据，顺序将如下，基于rate的降序值。 School2 - ＆gt; School1 - ＆gt; School3 80 - ＆gt; 70 - ＆gt; 60

我尝试使用dplyr包来获得所需的输出但尚未达到结果。

Answer 1

我们可以在2015年找到该费率，然后根据列进行排列。

library(dplyr)

dat2 <- dat %>%
  group_by(School) %>%
  mutate(Year2015 = Rate[Year == 2015]) %>%
  arrange(desc(Year2015), desc(Year)) %>%
  ungroup(School) %>%
  select(-Year2015)
dat2
# # A tibble: 9 x 3
#   School   Year  Rate
#   <fct>   <int> <int>
# 1 School2  2015    80
# 2 School2  2014    90
# 3 School2  2013    11
# 4 School1  2015    70
# 5 School1  2014    50
# 6 School1  2013    30
# 7 School3  2015    60
# 8 School3  2014    50
# 9 School3  2013    40

Answer 2

首先计算每所学校的最高费率（MaxRate）的选项。然后在MaxRate和Year上按降序排列数据。

library(dplyr)

data2 %>% group_by(School) %>%
  mutate(MaxRate = max(Rate)) %>%
  arrange(desc(MaxRate), desc(Year)) %>%
  ungroup() %>%
  select(-MaxRate) %>% as.data.frame()

# School Year Rate
# 1 School2 2015   80
# 2 School2 2014   90
# 3 School2 2013   11
# 4 School1 2015   70
# 5 School1 2014   50
# 6 School1 2013   30
# 7 School3 2015   60
# 8 School3 2014   50
# 9 School3 2013   40

根据一列中的值排序R数据帧中的行

2 个答案: