Question

我的数据看起来如下：

Participant  Round  Total 
1        100     5
1        101     8
1        102     12
1        200     42      
2        100     14 
2        101     71
40       100     32   
40       101     27
40       200     18

我希望得到一张表Total的最后Round（200）减去Total的{{1}}（100）;

例如 - 参与者1 - 它是Round。

最终输出应如下所示：

42 - 5 = 37

Answer 1

基础R

aggregate(Total ~ Participant, df[df$Round %in% c(100, 200), ], diff) 
#   Participant Total
# 1           1    37
# 2           2      
# 3          40   -14

或类似地与subset

组合

aggregate(Total ~ Participant, df, subset = Round %in% c(100, 200), diff)

或data.table

library(data.table) ;
setDT(df)[Round %in% c(100, 200), diff(Total), by = Participant]
#    Participant  V1
# 1:           1  37
# 2:          40 -14

或使用二元连接

setkey(setDT(df), Round)
df[.(c(100, 200)), diff(Total), by = Participant]
#    Participant  V1
# 1:           1  37
# 2:          40 -14

或dplyr

library(dplyr)
df %>%
  group_by(Participant) %>%
  filter(Round %in% c(100, 200)) %>%
  summarise(Total = diff(Total))
# Source: local data table [2 x 2]
# 
#   Participant Total
# 1           1    37
# 2          40   -14

Answer 2

试试这个：

df <- read.table(header = TRUE, text = "
Participant Round Total
                 1        100     5
1        101     8
1        102     12 
1        200     42      
2        100     14 
2        101     71
2 200 80
40       100     32   
40       101     27
40       200     18")

library(data.table)
setDT(df)[ , .(Total = Total[Round == 200] - Total[Round == 100]), by = Participant]

Answer 3

你可以试试这个

library(dplyr)
group_by(df, Participant) %>%
    filter(row_number()==1 | row_number()==max(row_number())) %>%
    mutate(df = diff(Total)) %>%
    select(Participant, df) %>%
    unique()
Source: local data frame [3 x 2]
Groups: Participant

  Participant  df
1           1  37
2           2  57
3          40 -14

Answer 4

每个人都喜欢sqldf，所以如果你的要求不是申请，那就试试吧：

首先是一些测试数据：

df <- read.table(header = TRUE, text = "
Participant Round Total
                 1        100     5
1        101     8
1        102     12 
1        200     42      
2        100     14 
2        101     71
2 200 80
40       100     32   
40       101     27
40       200     18")

接下来使用SQL创建2列 - 一列用于100轮，一列用于200轮并减去它们

rolled <- sqldf("
  SELECT tab_a.Participant AS Participant
        ,tab_b.Total_200 - tab_a.Total_100 AS Difference
    FROM (
        SELECT Participant
            ,Total AS Total_100
        FROM df
        WHERE Round = 100
        ) tab_a
    INNER JOIN (
        SELECT Participant
            ,Total AS Total_200
        FROM df
        WHERE Round = 200
        ) tab_b ON (tab_a.Participant = tab_b.Participant)
    ")

减去特定的行

4 个答案: