[英]dplyr count single observations in list of tibbles using purrr::map
我試圖計算包含單個觀察結果的小標題列表中出現的頻率,這些觀察值之間用“;”分隔。 我遇到了一個錯誤,當我使用purrr::map()
內purrr::map()
我懷疑我缺少一些簡單的東西,因此不勝感激。
以從不同客戶處購買的水果為例,其中同時購買的水果之間用“;”分隔。
# Fruit purchases across days with different number of customers.
day_1 <- as_data_frame(setNames(list(c("oranges;peaches;apples", "pears;apples", "bananas", "oranges;apples", "apples")), "fruits"))
day_2 <- as_data_frame(setNames(list(c("oranges;apples", "peaches","apples;bananas;", "pears", "apples;peaches", "oranges")), "fruits"))
day_3 <- as_data_frame(setNames(list(c("peaches;pears","apples","bananas")), "fruits"))
# Create list of fruit purchases.
fruit_list <- list(day_1, day_2, day_3)
這將返回三個小標題的列表,這是我的數據的一般格式。 我可以使用dplyr
/ purrr
來計算每天每種水果的總觀察purrr
:
fruit_list %>%
map(function(x) strsplit(x$fruits, ";")) %>%
map(unlist) %>%
map(table)
但是,當我嘗試使用map()
中的map()
隔離和匯總所有小點心列表中的單個水果時,我遇到了錯誤
“錯誤:
.x
不是向量(關閉)”
fruit_list %>%
map(mutate(fruit_count = map(function(x) strsplit(x$fruits, ";"), length))) %>%
filter(fruit_count==1) %>%
count(solo_fruits = fruits)
我可以在單個小標題/ df上執行此功能,但不能在小標題列表中進行。 我是否缺少map()
函數或更明顯的東西? 謝謝!
# A tibble: 2 x 2
solo_fruits n
<chr> <int>
1 apples 1
2 bananas 1
我如何得出單個樣本的上述答案:
day_1_df <- as.data.frame(fruit_list[[1]])
day_1_df %>%
mutate(fruit_count = map(strsplit(day_1_df$fruits, ";"), length)) %>%
filter(fruit_count==1) %>%
count(solo_fruits = fruits)
並非完全符合您的要求,但這可能會以其他方式解決您的問題:
library(tidyverse)
day_1 <- as_data_frame(setNames(list(c("oranges;peaches;apples", "pears;apples", "bananas", "oranges;apples", "apples")), "fruits"))
day_2 <- as_data_frame(setNames(list(c("oranges;apples", "peaches","apples;bananas;", "pears", "apples;peaches", "oranges")), "fruits"))
day_3 <- as_data_frame(setNames(list(c("peaches;pears","apples","bananas")), "fruits"))
df <- tibble(day = 1:3, fruits = c(day_1, day_2, day_3)) %>%
unnest() %>%
mutate(fruits = strsplit(fruits, ";"), customer = row_number()) %>%
unnest()
df %>%
group_by(customer) %>%
filter(n() == 1) %>%
group_by(customer, day, fruits) %>%
summarise(n = n())
# # A tibble: 7 x 4
# # Groups: customer, day [?]
# customer day fruits n
# <int> <int> <chr> <int>
# 1 3 1 bananas 1
# 2 5 1 apples 1
# 3 7 2 peaches 1
# 4 9 2 pears 1
# 5 11 2 oranges 1
# 6 13 3 apples 1
# 7 14 3 bananas 1
編輯:誤解后更改
您可以僅使用str_detect
捕獲沒有行;
。 或者您可以使用str_count進行計數;
然后加1。
fruit_list%>%
map(~filter(.x,!str_detect(fruits,";"))%>%
mutate(solo_fruits = fruits,count = 1,fruits=NULL))
[[1]]
# A tibble: 2 x 2
solo_fruits count
<chr> <dbl>
1 bananas 1
2 apples 1
[[2]]
# A tibble: 3 x 2
solo_fruits count
<chr> <dbl>
1 peaches 1
2 pears 1
3 oranges 1
[[3]]
# A tibble: 2 x 2
solo_fruits count
<chr> <dbl>
1 apples 1
2 bananas 1
我使用str_count
意思是:它將為您提供每行水果的總數。 而不是分裂,然后使用長度
fruit_list%>%
map(~mutate(.x,count = str_count(fruits,";") + 1))
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.