如何用R中的子字符串的反向替换子字符串？
基数R中的chartr函数帮助我们用新字符串替换旧字符串，因此它也可以用来替换该子字符串的相反子字符串。例如，如果我们有一个向量x，其中包含tutorialpsoint，并且想要将其转换为nhooo，则可以将其作为chartr（“tutorialpsoint”，“nhooo”，x）来完成。
例1
> x1<-"IDNIA" > x1
输出结果
[1] "IDNIA"
示例
> chartr("DN","ND",x1)输出结果
[1] "INDIA"
例2
> x2<-sample(c("IDNIA","IDNONESIA"),50,,replace=TRUE)
> x2输出结果
[1] "IDNIA" "IDNIA" "IDNIA" "IDNONESIA" "IDNIA" "IDNONESIA" [7] "IDNONESIA" "IDNIA" "IDNONESIA" "IDNIA" "IDNIA" "IDNONESIA" [13] "IDNONESIA" "IDNONESIA" "IDNIA" "IDNONESIA" "IDNIA" "IDNIA" [19] "IDNONESIA" "IDNONESIA" "IDNIA" "IDNONESIA" "IDNIA" "IDNIA" [25] "IDNONESIA" "IDNIA" "IDNIA" "IDNIA" "IDNONESIA" "IDNONESIA" [31] "IDNONESIA" "IDNONESIA" "IDNONESIA" "IDNONESIA" "IDNIA" "IDNIA" [37] "IDNIA" "IDNONESIA" "IDNIA" "IDNIA" "IDNONESIA" "IDNIA" [43] "IDNONESIA" "IDNIA" "IDNONESIA" "IDNONESIA" "IDNONESIA" "IDNIA" [49] "IDNONESIA" "IDNONESIA"
示例
> chartr("DN","ND",x2)输出结果
[1] "INDIA" "INDIA" "INDIA" "INDODESIA" "INDIA" "INDODESIA" [7] "INDODESIA" "INDIA" "INDODESIA" "INDIA" "INDIA" "INDODESIA" [13] "INDODESIA" "INDODESIA" "INDIA" "INDODESIA" "INDIA" "INDIA" [19] "INDODESIA" "INDODESIA" "INDIA" "INDODESIA" "INDIA" "INDIA" [25] "INDODESIA" "INDIA" "INDIA" "INDIA" "INDODESIA" "INDODESIA" [31] "INDODESIA" "INDODESIA" "INDODESIA" "INDODESIA" "INDIA" "INDIA" [37] "INDIA" "INDODESIA" "INDIA" "INDIA" "INDODESIA" "INDIA" [43] "INDODESIA" "INDIA" "INDODESIA" "INDODESIA" "INDODESIA" "INDIA" [49] "INDODESIA" "INDODESIA"
例子3
> x3<-sample(c("Litre","Metre","Millimitre","Millilitre"),120,,replace=TRUE)
> x3输出结果
[1] "Litre" "Millimitre" "Metre" "Metre" "Litre" [6] "Metre" "Millilitre" "Litre" "Millimitre" "Millimitre" [11] "Millilitre" "Millilitre" "Millilitre" "Litre" "Litre" [16] "Millilitre" "Millilitre" "Litre" "Litre" "Millilitre" [21] "Metre" "Millimitre" "Metre" "Millimitre" "Millilitre" [26] "Millimitre" "Millimitre" "Metre" "Millimitre" "Metre" [31] "Millimitre" "Millimitre" "Millimitre" "Millilitre" "Millimitre" [36] "Millilitre" "Millilitre" "Millilitre" "Metre" "Litre" [41] "Millimitre" "Millilitre" "Litre" "Litre" "Metre" [46] "Litre" "Millimitre" "Metre" "Metre" "Metre" [51] "Millimitre" "Litre" "Millilitre" "Millimitre" "Millimitre" [56] "Litre" "Litre" "Millilitre" "Metre" "Millimitre" [61] "Metre" "Litre" "Millimitre" "Metre" "Metre" [66] "Millilitre" "Metre" "Litre" "Millimitre" "Litre" [71] "Metre" "Millimitre" "Millilitre" "Millimitre" "Millimitre" [76] "Metre" "Metre" "Litre" "Millimitre" "Litre" [81] "Litre" "Millilitre" "Litre" "Litre" "Litre" [86] "Millimitre" "Litre" "Litre" "Metre" "Litre" [91] "Litre" "Litre" "Litre" "Metre" "Metre" [96] "Millimitre" "Metre" "Litre" "Millilitre" "Millimitre" [101] "Millilitre" "Millimitre" "Millimitre" "Metre" "Millilitre" [106] "Millimitre" "Litre" "Millilitre" "Litre" "Millilitre" [111] "Metre" "Millilitre" "Millimitre" "Millilitre" "Millimitre" [116] "Litre" "Litre" "Millilitre" "Millimitre" "Litre"
示例
> chartr("re","er",x3)输出结果
[1] "Liter" "Millimiter" "Mrter" "Mrter" "Liter" [6] "Mrter" "Milliliter" "Liter" "Millimiter" "Millimiter" [11] "Milliliter" "Milliliter" "Milliliter" "Liter" "Liter" [16] "Milliliter" "Milliliter" "Liter" "Liter" "Milliliter" [21] "Mrter" "Millimiter" "Mrter" "Millimiter" "Milliliter" [26] "Millimiter" "Millimiter" "Mrter" "Millimiter" "Mrter" [31] "Millimiter" "Millimiter" "Millimiter" "Milliliter" "Millimiter" [36] "Milliliter" "Milliliter" "Milliliter" "Mrter" "Liter" [41] "Millimiter" "Milliliter" "Liter" "Liter" "Mrter" [46] "Liter" "Millimiter" "Mrter" "Mrter" "Mrter" [51] "Millimiter" "Liter" "Milliliter" "Millimiter" "Millimiter" [56] "Liter" "Liter" "Milliliter" "Mrter" "Millimiter" [61] "Mrter" "Liter" "Millimiter" "Mrter" "Mrter" [66] "Milliliter" "Mrter" "Liter" "Millimiter" "Liter" [71] "Mrter" "Millimiter" "Milliliter" "Millimiter" "Millimiter" [76] "Mrter" "Mrter" "Liter" "Millimiter" "Liter" [81] "Liter" "Milliliter" "Liter" "Liter" "Liter" [86] "Millimiter" "Liter" "Liter" "Mrter" "Liter" [91] "Liter" "Liter" "Liter" "Mrter" "Mrter" [96] "Millimiter" "Mrter" "Liter" "Milliliter" "Millimiter" [101] "Milliliter" "Millimiter" "Millimiter" "Mrter" "Milliliter" [106] "Millimiter" "Liter" "Milliliter" "Liter" "Milliliter" [111] "Mrter" "Milliliter" "Millimiter" "Milliliter" "Millimiter" [116] "Liter" "Liter" "Milliliter" "Millimiter" "Liter"
例子4
> x4<-sample(c("afterglwo","deathblwo","alpenglwo"),80,,replace=TRUE)
> x4输出结果
[1] "deathblwo" "afterglwo" "alpenglwo" "deathblwo" "deathblwo" "deathblwo" [7] "afterglwo" "afterglwo" "alpenglwo" "afterglwo" "deathblwo" "afterglwo" [13] "deathblwo" "deathblwo" "afterglwo" "deathblwo" "afterglwo" "afterglwo" [19] "afterglwo" "alpenglwo" "afterglwo" "deathblwo" "afterglwo" "deathblwo" [25] "deathblwo" "deathblwo" "alpenglwo" "afterglwo" "afterglwo" "afterglwo" [31] "deathblwo" "alpenglwo" "deathblwo" "afterglwo" "alpenglwo" "deathblwo" [37] "deathblwo" "deathblwo" "alpenglwo" "afterglwo" "afterglwo" "afterglwo" [43] "deathblwo" "deathblwo" "deathblwo" "afterglwo" "deathblwo" "afterglwo" [49] "afterglwo" "afterglwo" "deathblwo" "deathblwo" "alpenglwo" "afterglwo" [55] "afterglwo" "alpenglwo" "deathblwo" "afterglwo" "deathblwo" "deathblwo" [61] "deathblwo" "deathblwo" "deathblwo" "deathblwo" "deathblwo" "afterglwo" [67] "deathblwo" "afterglwo" "alpenglwo" "afterglwo" "deathblwo" "afterglwo" [73] "afterglwo" "alpenglwo" "afterglwo" "alpenglwo" "alpenglwo" "deathblwo" [79] "alpenglwo" "afterglwo"
示例
> chartr("ow","wo",x4)输出结果
[1] "deathblow" "afterglow" "alpenglow" "deathblow" "deathblow" "deathblow" [7] "afterglow" "afterglow" "alpenglow" "afterglow" "deathblow" "afterglow" [13] "deathblow" "deathblow" "afterglow" "deathblow" "afterglow" "afterglow" [19] "afterglow" "alpenglow" "afterglow" "deathblow" "afterglow" "deathblow" [25] "deathblow" "deathblow" "alpenglow" "afterglow" "afterglow" "afterglow" [31] "deathblow" "alpenglow" "deathblow" "afterglow" "alpenglow" "deathblow" [37] "deathblow" "deathblow" "alpenglow" "afterglow" "afterglow" "afterglow" [43] "deathblow" "deathblow" "deathblow" "afterglow" "deathblow" "afterglow" [49] "afterglow" "afterglow" "deathblow" "deathblow" "alpenglow" "afterglow" [55] "afterglow" "alpenglow" "deathblow" "afterglow" "deathblow" "deathblow" [61] "deathblow" "deathblow" "deathblow" "deathblow" "deathblow" "afterglow" [67] "deathblow" "afterglow" "alpenglow" "afterglow" "deathblow" "afterglow" [73] "afterglow" "alpenglow" "afterglow" "alpenglow" "alpenglow" "deathblow" [79] "alpenglow" "afterglow"