R 滞后两个变量答案

【问题标题】：R Lag Two VariablesR 滞后两个变量
【发布时间】：2022-11-23 21:06:29
【问题描述】：

DATA = data.frame(STUDENT = c(1,1,1,1,1,1,2,2,2,2,2, 3,3,3),
                  YEAR = c(2000, 2000, 2000, 2001, 2001, 2001, 2000, 2000, 2001, 2001, 2001, 2001, 2001, 2001),
                  TRIMESTER= c(1,2,3,1,2,3,2,3,1,2,3,1,2,3),
                  SCORE = c(5,7,8,9,10,3,4,6,3,1,2,3,6, 9),
                  WANT = c(NA,NA,NA,4,3,-5,NA,NA,NA,-3,-4,NA,NA,NA))

我有 DATA 并希望创建通过以下方式计算的“WANT”：

对于每个学生，找到 SCORE，其中 (YEAR = YEAR +1, TRIMESTER = TRIMESTER) 并计算差值。

EX: SCORE(STUDENT = 1, TRIMESTER = 1, YEAR = 2001) - SCORE(STUDENT = 1, TRIMESTER = 1, YEAR = 2000)

【问题讨论】：

标签： r case lag

【解决方案1】：

这会做你想要的吗？

library(tidyverse)

DATA = data.frame(STUDENT = c(1,1,1,1,1,1,2,2,2,2,2, 3,3,3),
                  YEAR = c(2000, 2000, 2000, 2001, 2001, 2001, 2000, 2000, 2001, 2001, 2001, 2001, 2001, 2001),
                  TRIMESTER= c(1,2,3,1,2,3,2,3,1,2,3,1,2,3),
                  SCORE = c(5,7,8,9,10,3,4,6,3,1,2,3,6, 9),
                  WANT = c(NA,NA,NA,4,3,-5,NA,NA,NA,-3,-4,NA,NA,NA))

DATA <- as_tibble(DATA)

DATA %>% 
    group_by(STUDENT, TRIMESTER) %>% 
    mutate(LAST = lag(SCORE),
           DIFF = SCORE - LAST)
#> # A tibble: 14 x 7
#> # Groups:   STUDENT, TRIMESTER [9]
#>    STUDENT  YEAR TRIMESTER SCORE  WANT  LAST  DIFF
#>      <dbl> <dbl>     <dbl> <dbl> <dbl> <dbl> <dbl>
#>  1       1  2000         1     5    NA    NA    NA
#>  2       1  2000         2     7    NA    NA    NA
#>  3       1  2000         3     8    NA    NA    NA
#>  4       1  2001         1     9     4     5     4
#>  5       1  2001         2    10     3     7     3
#>  6       1  2001         3     3    -5     8    -5
#>  7       2  2000         2     4    NA    NA    NA
#>  8       2  2000         3     6    NA    NA    NA
#>  9       2  2001         1     3    NA    NA    NA
#> 10       2  2001         2     1    -3     4    -3
#> 11       2  2001         3     2    -4     6    -4
#> 12       3  2001         1     3    NA    NA    NA
#> 13       3  2001         2     6    NA    NA    NA
#> 14       3  2001         3     9    NA    NA    NA

^{创建于 2022-11-23 reprex v2.0.2}

【讨论】：