这里我设计了一个名为 的函数count_fun
,它有四个参数。dat
是一个数据框A
,Scol
是一个带有字符串的列,Gcol
是分组列,String
是测试字符串。请参阅https://cran.r-project.org/web/packages/dplyr/vignettes/programming.html了解如何使用dplyr
.
library(dplyr)
library(stringr)
count_fun <- function(dat, Scol, Gcol, String){
Scol <- enquo(Scol)
Gcol <- enquo(Gcol)
dat2 <- dat %>%
filter(str_detect(!!Scol, String)) %>%
group_by(!!Gcol) %>%
summarize(n())
return(dat2)
}
count_fun(A, a1, a2, "AB")
# # A tibble: 2 x 2
# a2 `n()`
# <chr> <int>
# 1 CAFE 2
# 2 DRINK 2
count_fun(A, a1, a2, "BF")
# # A tibble: 2 x 2
# a2 `n()`
# <chr> <int>
# 1 CAFE 1
# 2 DRINK 1
然后我们可以应用count_fun
usinglapply
来遍历B
.
lapply(B$b1, function(x){
count_fun(A, a1, a2, x)
})
# [[1]]
# # A tibble: 2 x 2
# a2 `n()`
# <chr> <int>
# 1 CAFE 2
# 2 DRINK 2
#
# [[2]]
# # A tibble: 2 x 2
# a2 `n()`
# <chr> <int>
# 1 CAFE 1
# 2 DRINK 1
数据
A <- read.table(text = "a1 a2
ABC CAFE
ABD DRINK
ABF CAFE
ABFF DRINK
",
header = TRUE, stringsAsFactors = FALSE)
B <- data.frame(b1 = c("AB", "BF"), stringsAsFactors = FALSE)