从字符串匹配中总结

Question

我有这个 df 列：

df <- data.frame(Strings = c("ñlas onepojasd", "onenañdsl", "ñelrtwofkld", "asdthreeasp", "asdfetwoasd", "fouroqwke","okasdtwo", "acmofour", "porefour", "okstwo"))
> df
          Strings
1  ñlas onepojasd
2       onenañdsl
3     ñelrtwofkld
4     asdthreeasp
5     asdfetwoasd
6       fouroqwke
7        okasdtwo
8        acmofour
9        porefour
10         okstwo

我知道 df$Strings 中的每个值都会与单词 one, two, three or four 匹配。而且我也知道它只会与这些词中的一个相匹配。所以要匹配它们：

str_detect(df$Strings,"one")
str_detect(df$Strings,"two")
str_detect(df$Strings,"three")
str_detect(df$Strings,"four")

但是，我被困在这里，因为我正在尝试这样做 table:

Homes  Quantity Percent
  One         2     0.3
  Two         4     0.4
Three         1     0.1
 Four         3     0.3
Total        10       1

Answer 1

您可以使用 str_extract，然后执行 table 和 prop.table，即

library(stringr)

str_extract(df1$Strings, 'one|two|three|four')
#[1] "one"   "one"   "two"   "three" "two"   "four"  "two"   "four"  "four"  "two"  

table(str_extract(df1$Strings, 'one|two|three|four'))
# four   one three   two 
#    3     2     1     4 

prop.table(table(str_extract(df1$Strings, 'one|two|three|four')))
# four   one three   two 
#  0.3   0.2   0.1   0.4

Answer 2

使用 tidyverse 和 janitor 你可以：

df %>%
 mutate(Homes = str_extract(Strings, "one|two|three|four"),
        n = n()) %>%
 group_by(Homes) %>%
 summarise(Quantity = length(Homes),
           Percent = first(length(Homes)/n)) %>%
 adorn_totals("row")

 Homes Quantity Percent
  four        3     0.3
   one        2     0.2
 three        1     0.1
   two        4     0.4
 Total       10     1.0

或仅 tidyverse:

 df %>%
 mutate(Homes = str_extract(Strings, "one|two|three|four"),
        n = n()) %>%
 group_by(Homes) %>%
 summarise(Quantity = length(Homes),
           Percent = first(length(Homes)/n)) %>%
 rbind(., data.frame(Homes = "Total", Quantity = sum(.$Quantity), 
                     Percent = sum(.$Percent)))

在这两种情况下，代码首先提取匹配模式并计算案例数。其次，它按匹配的词分组。第三，它计算每个单词的案例数和所有单词中给定单词的比例。最后，它添加了一个 "Total" 行。

Answer 3

base R 选项将是 regmatches/regexpr 和 table

table(regmatches(df$Strings, regexpr('one|two|three|four', df$Strings)))
#  four   one three   two 
#    3     2     1     4

加上 addmargins 得到 sum 然后除以

out <- addmargins(table(regmatches(df$Strings, 
     regexpr('one|two|three|four', df$Strings))))
out/out[length(out)]

# four   one three   two   Sum 
#  0.3   0.2   0.1   0.4   1.0

从字符串匹配中总结

summarize from string matches

string

r

summary