根据子字符串从无组织数据创建列

时间:2017-12-30 17:05:23

标签: r sorting substring reshape grepl

我的论文数据面临以下问题。我有一个数据框,在第一列" id"之后有水平无组织的字符串单元格。我想在行中组织字符串,以便以相同的前4个字符开头的所有字符串将保留在同一列中。

由于相关类别数量有限(少于20个),我可以手动执行此操作,首先是#34; Arra"然后是" Comm"等等。我用grepl尝试了这个,但未能返回原始的单元格字符串。我只得到TRUE / FALSE。非常感谢你的帮助!

我目前的数据是这样的。 (我把NA细胞留空了)

id  col2              col3               col4         col5
3   Commitment 100    Lead Mgmt 15      Arranger 50
8   Arrangement 20    Front-end 80
16  Lead mgmt 40      Commitmnt 20
17
20  Arranger 50     

这就是它应该是这样的:

id  Arra           Comm            Fron         Lead
3   Arranger 50    Commitment 100               Lead Mgmt 15
8   Arrangement 20                 Front-end 80
16                 Commitmnt 20                 Lead mgmt 40
17
20  Arranger 50

1 个答案:

答案 0 :(得分:3)

这是一种可行的方法:

library(data.table)
dcast(melt(as.data.table(mydf), "id", na.rm = TRUE)[value != ""][
  , ind := substr(value, 1, 4)], id ~ ind, value.var = "value", fill = "")
#    id           Arra           Comm         Fron         Lead
# 1:  3    Arranger 50 Commitment 100              Lead Mgmt 15
# 2:  8 Arrangement 20                Front-end 80             
# 3: 16                  Commitmnt 20              Lead mgmt 40
# 4: 20    Arranger 50   

并且,在“tidyverse”中使用类似的逻辑:

library(tidyverse)
mydf[is.na(mydf)] <- ""
mydf %>%
  gather(var, val, starts_with("col")) %>%
  filter(val != "") %>%
  mutate(ind = substr(val, 1, 4)) %>%
  select(-var) %>%
  spread(ind, val)
#   id           Arra           Comm         Fron         Lead
# 1  3    Arranger 50 Commitment 100         <NA> Lead Mgmt 15
# 2  8 Arrangement 20           <NA> Front-end 80         <NA>
# 3 16           <NA>   Commitmnt 20         <NA> Lead mgmt 40
# 4 20    Arranger 50           <NA>         <NA>         <NA>

示例数据:

mydf <- structure(list(id = c(3L, 8L, 16L, 17L, 20L), col2 = c("Commitment 100", 
    "Arrangement 20", "Lead mgmt 40", "", "Arranger 50"), col3 = c("Lead Mgmt 15", 
    "Front-end 80", "Commitmnt 20", "", ""), col4 = c("Arranger 50", 
    "", "", "", ""), col5 = c(NA, NA, NA, NA, NA)), .Names = c("id", 
    "col2", "col3", "col4", "col5"), row.names = c(NA, 5L), class = "data.frame")

如果原始数据中存在重复的存根,例如,如果第1行中的“col5”具有另一个“承诺”值:

mydf$col5[1] <- "Commitment 99"
你可以尝试这样的事情:

dcast(melt(as.data.table(mydf), "id", na.rm = TRUE)[value != ""][
  , ind := substr(value, 1, 4)], 
  id ~ ind + rowid(id, ind), value.var = "value", fill = "")
#    id         Arra_1         Comm_1        Comm_2       Fron_1       Lead_1
# 1:  3    Arranger 50 Commitment 100 Commitment 99              Lead Mgmt 15
# 2:  8 Arrangement 20                              Front-end 80             
# 3: 16                  Commitmnt 20                            Lead mgmt 40
# 4: 20    Arranger 50                                                       

或者这个:

dcast(melt(as.data.table(mydf), "id", na.rm = TRUE)[value != ""][
  , ind := substr(value, 1, 4)], 
  id ~ ind, value.var = "value", fun = function(x) x[1], fill = "")
#    id           Arra           Comm         Fron         Lead
# 1:  3    Arranger 50 Commitment 100              Lead Mgmt 15
# 2:  8 Arrangement 20                Front-end 80             
# 3: 16                  Commitmnt 20              Lead mgmt 40
# 4: 20    Arranger 50                                         

取决于您所需的输出。