问题描述
这是我的最小示例,是我的图书数据集(按单词划分)的简化版本。
structure(list(word = c("in","großer","erregung","umstehen","bauersleute","knechte","und","mägde","das","gehöft","des","servaz","amareller","bauers","im","hemmernmoos","besprechen","den","einleitung","lieber","leser","weißt","du","was","wort","greenhorn","bedeutet","eine","höchst","ärgerliche","despektierliche","bezeichnung","für","denjenigen","auf","zum","alm","öhi","hinauf","vom","freundlichen","dorfe","maienfeld","führt","ein","fußweg","durch","grüne","baumreiche","fluren","bis","fuße","der"),word_id = c(1L,2L,3L,4L,5L,6L,7L,8L,9L,10L,11L,12L,13L,14L,15L,16L,17L,18L,19L,1L,19L),book = c("bergrichters","bergrichters","winnetou","heidilehr","heidilehr")),row.names = c(NA,-57L
),groups = structure(list(word = c("alm","der","in","zum"),.rows = structure(list(40L,32L,38L,52L,29L,35L,54L,c(9L,26L
),37L,57L,34L,45L,24L,50L,48L,30L,20L,53L,44L,47L,36L,56L,49L,28L,51L,42L,31L,22L,21L,46L,41L,c(7L,33L),43L,25L,23L,27L,c(39L,55L)),ptype = integer(0),class = c("vctrs_list_of","vctrs_vctr","list"))),53L),class = c("tbl_df","tbl","data.frame"),.drop = TRUE),class = c("grouped_df","tbl_df","data.frame"))
因为这些书没有章节,出于分析的目的,我想插入一个名为“ section”的“假”章节列,该列将每本书(group_by)按比例分成10个块(每本书10个章节),根据每本书的实际行数,并从1到10依次命名各节。
使用dplyr时,我找不到解决方案,也不知道如何实现。有什么建议? 谢谢!
解决方法
一种方法是利用cut
将每个book
分为10个部分。
library(dplyr)
df %>%
group_by(book) %>%
mutate(section = cut(row_number(),breaks = 10,labels = FALSE))
# word word_id book section
# <chr> <int> <chr> <int>
# 1 in 1 bergrichters 1
# 2 großer 2 bergrichters 1
# 3 erregung 3 bergrichters 2
# 4 umstehen 4 bergrichters 2
# 5 bauersleute 5 bergrichters 3
# 6 knechte 6 bergrichters 3
# 7 und 7 bergrichters 4
# 8 mägde 8 bergrichters 4
# 9 das 9 bergrichters 5
#10 gehöft 10 bergrichters 5
# … with 47 more rows
这也可以使用ave
在基数R中完成:
df$section <- with(df,ave(word_id,book,FUN = function(x)
cut(seq_along(x),labels = FALSE)))