如何在R中的n个字符后用三个点截断字符向量？
在stringr包的str_trunc函数的帮助下，可以在n个字符后用三个点截断字符向量。例如，如果我们有一个字符向量x并且每个值包含10个字符，那么可以使用命令str_trunc(x,8)在5个字符后用三个点截断这些值。
示例1
> x1<-sample(c("abcbefgh","ijklmnopq","rstuvwxyz"),100,replace=TRUE)
> x1输出结果[1] "rstuvwxyz" "rstuvwxyz" "abcbefgh" "rstuvwxyz" "ijklmnopq" "ijklmnopq" [7] "ijklmnopq" "rstuvwxyz" "rstuvwxyz" "rstuvwxyz" "rstuvwxyz" "abcbefgh" [13] "rstuvwxyz" "abcbefgh" "abcbefgh" "ijklmnopq" "ijklmnopq" "ijklmnopq" [19] "ijklmnopq" "rstuvwxyz" "rstuvwxyz" "abcbefgh" "abcbefgh" "ijklmnopq" [25] "ijklmnopq" "ijklmnopq" "rstuvwxyz" "rstuvwxyz" "rstuvwxyz" "rstuvwxyz" [31] "rstuvwxyz" "abcbefgh" "abcbefgh" "rstuvwxyz" "rstuvwxyz" "abcbefgh" [37] "ijklmnopq" "abcbefgh" "rstuvwxyz" "ijklmnopq" "abcbefgh" "ijklmnopq" [43] "rstuvwxyz" "ijklmnopq" "abcbefgh" "rstuvwxyz" "abcbefgh" "abcbefgh" [49] "rstuvwxyz" "ijklmnopq" "rstuvwxyz" "ijklmnopq" "ijklmnopq" "ijklmnopq" [55] "rstuvwxyz" "ijklmnopq" "abcbefgh" "rstuvwxyz" "ijklmnopq" "ijklmnopq" [61] "abcbefgh" "abcbefgh" "rstuvwxyz" "abcbefgh" "ijklmnopq" "ijklmnopq" [67] "rstuvwxyz" "abcbefgh" "abcbefgh" "abcbefgh" "ijklmnopq" "abcbefgh" [73] "rstuvwxyz" "rstuvwxyz" "ijklmnopq" "ijklmnopq" "ijklmnopq" "ijklmnopq" [79] "ijklmnopq" "rstuvwxyz" "rstuvwxyz" "abcbefgh" "abcbefgh" "ijklmnopq" [85] "ijklmnopq" "abcbefgh" "abcbefgh" "rstuvwxyz" "abcbefgh" "abcbefgh" [91] "rstuvwxyz" "rstuvwxyz" "ijklmnopq" "rstuvwxyz" "ijklmnopq" "ijklmnopq" [97] "abcbefgh" "abcbefgh" "ijklmnopq" "ijklmnopq"
示例
> library(stringr) > str_trunc(x1,5)输出结果
[1] "rs..." "rs..." "ab..." "rs..." "ij..." "ij..." "ij..." "rs..." "rs..." [10] "rs..." "rs..." "ab..." "rs..." "ab..." "ab..." "ij..." "ij..." "ij..." [19] "ij..." "rs..." "rs..." "ab..." "ab..." "ij..." "ij..." "ij..." "rs..." [28] "rs..." "rs..." "rs..." "rs..." "ab..." "ab..." "rs..." "rs..." "ab..." [37] "ij..." "ab..." "rs..." "ij..." "ab..." "ij..." "rs..." "ij..." "ab..." [46] "rs..." "ab..." "ab..." "rs..." "ij..." "rs..." "ij..." "ij..." "ij..." [55] "rs..." "ij..." "ab..." "rs..." "ij..." "ij..." "ab..." "ab..." "rs..." [64] "ab..." "ij..." "ij..." "rs..." "ab..." "ab..." "ab..." "ij..." "ab..." [73] "rs..." "rs..." "ij..." "ij..." "ij..." "ij..." "ij..." "rs..." "rs..." [82] "ab..." "ab..." "ij..." "ij..." "ab..." "ab..." "rs..." "ab..." "ab..." [91] "rs..." "rs..." "ij..." "rs..." "ij..." "ij..." "ab..." "ab..." "ij..." [100] "ij..."
示例
> str_trunc(x1,7)输出结果
[1] "rstu..." "rstu..." "abcb..." "rstu..." "ijkl..." "ijkl..." "ijkl..." [8] "rstu..." "rstu..." "rstu..." "rstu..." "abcb..." "rstu..." "abcb..." [15] "abcb..." "ijkl..." "ijkl..." "ijkl..." "ijkl..." "rstu..." "rstu..." [22] "abcb..." "abcb..." "ijkl..." "ijkl..." "ijkl..." "rstu..." "rstu..." [29] "rstu..." "rstu..." "rstu..." "abcb..." "abcb..." "rstu..." "rstu..." [36] "abcb..." "ijkl..." "abcb..." "rstu..." "ijkl..." "abcb..." "ijkl..." [43] "rstu..." "ijkl..." "abcb..." "rstu..." "abcb..." "abcb..." "rstu..." [50] "ijkl..." "rstu..." "ijkl..." "ijkl..." "ijkl..." "rstu..." "ijkl..." [57] "abcb..." "rstu..." "ijkl..." "ijkl..." "abcb..." "abcb..." "rstu..." [64] "abcb..." "ijkl..." "ijkl..." "rstu..." "abcb..." "abcb..." "abcb..." [71] "ijkl..." "abcb..." "rstu..." "rstu..." "ijkl..." "ijkl..." "ijkl..." [78] "ijkl..." "ijkl..." "rstu..." "rstu..." "abcb..." "abcb..." "ijkl..." [85] "ijkl..." "abcb..." "abcb..." "rstu..." "abcb..." "abcb..." "rstu..." [92] "rstu..." "ijkl..." "rstu..." "ijkl..." "ijkl..." "abcb..." "abcb..." [99] "ijkl..." "ijkl..."
示例
> str_trunc(x1,8)输出结果
[1] "rstuv..." "rstuv..." "abcbefgh" "rstuv..." "ijklm..." "ijklm..." [7] "ijklm..." "rstuv..." "rstuv..." "rstuv..." "rstuv..." "abcbefgh" [13] "rstuv..." "abcbefgh" "abcbefgh" "ijklm..." "ijklm..." "ijklm..." [19] "ijklm..." "rstuv..." "rstuv..." "abcbefgh" "abcbefgh" "ijklm..." [25] "ijklm..." "ijklm..." "rstuv..." "rstuv..." "rstuv..." "rstuv..." [31] "rstuv..." "abcbefgh" "abcbefgh" "rstuv..." "rstuv..." "abcbefgh" [37] "ijklm..." "abcbefgh" "rstuv..." "ijklm..." "abcbefgh" "ijklm..." [43] "rstuv..." "ijklm..." "abcbefgh" "rstuv..." "abcbefgh" "abcbefgh" [49] "rstuv..." "ijklm..." "rstuv..." "ijklm..." "ijklm..." "ijklm..." [55] "rstuv..." "ijklm..." "abcbefgh" "rstuv..." "ijklm..." "ijklm..." [61] "abcbefgh" "abcbefgh" "rstuv..." "abcbefgh" "ijklm..." "ijklm..." [67] "rstuv..." "abcbefgh" "abcbefgh" "abcbefgh" "ijklm..." "abcbefgh" [73] "rstuv..." "rstuv..." "ijklm..." "ijklm..." "ijklm..." "ijklm..." [79] "ijklm..." "rstuv..." "rstuv..." "abcbefgh" "abcbefgh" "ijklm..." [85] "ijklm..." "abcbefgh" "abcbefgh" "rstuv..." "abcbefgh" "abcbefgh" [91] "rstuv..." "rstuv..." "ijklm..." "rstuv..." "ijklm..." "ijklm..." [97] "abcbefgh" "abcbefgh" "ijklm..." "ijklm..."
例2
> x2<-c("Alabama", "Alaska", "American Samoa", "Arizona", "Arkansas", "California", "Colorado", "Connecticut", "Delaware", "District of Columbia", "Florida", "Georgia", "Guam", "Hawaii", "Idaho", "Illinois", "Indiana", "Iowa", "Kansas", "Kentucky", "Louisiana", "Maine", "Maryland", "Massachusetts", "Michigan", "Minnesota", "Minor Outlying Islands", "Mississippi", "Missouri", "Montana", "Nebraska", "Nevada", "New Hampshire", "New Jersey", "New Mexico", "New York", "North Carolina", "North Dakota", "Northern Mariana Islands", "Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Puerto Rico", "Rhode Island", "South Carolina", "South Dakota", "Tennessee", "Texas", "U.S. Virgin Islands", "Utah", "Vermont", "Virginia", "Washington", "West Virginia", "Wisconsin", "Wyoming")
> x2输出结果[1] "Alabama" "Alaska" [3] "American Samoa" "Arizona" [5] "Arkansas" "California" [7] "Colorado" "Connecticut" [9] "Delaware" "District of Columbia" [11] "Florida" "Georgia" [13] "Guam" "Hawaii" [15] "Idaho" "Illinois" [17] "Indiana" "Iowa" [19] "Kansas" "Kentucky" [21] "Louisiana" "Maine" [23] "Maryland" "Massachusetts" [25] "Michigan" "Minnesota" [27] "Minor Outlying Islands" "Mississippi" [29] "Missouri" "Montana" [31] "Nebraska" "Nevada" [33] "New Hampshire" "New Jersey" [35] "New Mexico" "New York" [37] "North Carolina" "North Dakota" [39] "Northern Mariana Islands" "Ohio" [41] "Oklahoma" "Oregon" [43] "Pennsylvania" "Puerto Rico" [45] "Rhode Island" "South Carolina" [47] "South Dakota" "Tennessee" [49] "Texas" "U.S. Virgin Islands" [51] "Utah" "Vermont" [53] "Virginia" "Washington" [55] "West Virginia" "Wisconsin" [57] "Wyoming"
示例
str_trunc(x2,5)输出结果
[1] "Al..." "Al..." "Am..." "Ar..." "Ar..." "Ca..." "Co..." "Co..." "De..." [10] "Di..." "Fl..." "Ge..." "Guam" "Ha..." "Idaho" "Il..." "In..." "Iowa" [19] "Ka..." "Ke..." "Lo..." "Maine" "Ma..." "Ma..." "Mi..." "Mi..." "Mi..." [28] "Mi..." "Mi..." "Mo..." "Ne..." "Ne..." "Ne..." "Ne..." "Ne..." "Ne..." [37] "No..." "No..." "No..." "Ohio" "Ok..." "Or..." "Pe..." "Pu..." "Rh..." [46] "So..." "So..." "Te..." "Texas" "U...." "Utah" "Ve..." "Vi..." "Wa..." [55] "We..." "Wi..." "Wy..."
示例
> str_trunc(x2,4)输出结果
[1] "A..." "A..." "A..." "A..." "A..." "C..." "C..." "C..." "D..." "D..." [11] "F..." "G..." "Guam" "H..." "I..." "I..." "I..." "Iowa" "K..." "K..." [21] "L..." "M..." "M..." "M..." "M..." "M..." "M..." "M..." "M..." "M..." [31] "N..." "N..." "N..." "N..." "N..." "N..." "N..." "N..." "N..." "Ohio" [41] "O..." "O..." "P..." "P..." "R..." "S..." "S..." "T..." "T..." "U..." [51] "Utah" "V..." "V..." "W..." "W..." "W..." "W..."