R反转数据框中的字符串答案

【问题标题】：R reverse strings in a data frameR反转数据框中的字符串
【发布时间】：2017-11-30 00:28:35
【问题描述】：

我有一个大数据框，如果字符串与列 ref 不同，我想反转字符串，例如，我想将 GA 更改为 AG 并保持其余部分不变。

structure(list(number = c("rs1", "rs2", "rs3", "rs4", "rs5", 
"rs6"), ref = c("AG", "AG", "AG", "AG", "AC", "AC"), s1 = c("GA", 
"AG", "GA", "AG", "CA", "AA"), s2 = c("AA", "GG", "GA", "AA", 
"AA", "AC"), s3 = c("GG", "AG", "GG", "AA", "CC", "AC"), s4 = c("GA", 
"GG", "GA", "AA", "AA", "CC"), s5 = c("AA", "GG", "GA", "GG", 
"AA", "CC"), s6 = c("AA", "AG", "GG", "AG", "AA", "CC")), .Names = 
c("number", 
"ref", "s1", "s2", "s3", "s4", "s5", "s6"), class = "data.frame", 
row.names = c(NA, 
-6L))

Input:
number  ref s1  s2  s3  s4  s5  s6 ...
rs1 AG  GA  AA  GG  GA  AA  AA ...
rs2 AG  AG  GG  AG  GG  GG  AG ...
rs3 AG  GA  GA  GG  GA  GA  GG ...
rs4 AG  AG  AA  AA  AA  GG  AG ...
rs5 AC  CA  AA  CC  AA  AA  AA ...
rs6 AC  AA  AC  AC  CC  CC  CC ...

Desired output:
number  ref s1  s2  s3  s4  s5  s6 ...
rs1 AG  AG  AA  GG  AG  AA  AA ...
rs2 AG  AG  GG  AG  GG  GG  AG ...
rs3 AG  AG  AG  GG  AG  AG  GG ...
rs4 AG  AG  AA  AA  AA  GG  AG ...
rs5 AC  AC  AA  CC  AA  AA  AA ...
rs6 AC  AA  AC  AC  CC  CC  CC ...

我尝试使用 library(stingi) stri_reverse 函数

df.1 <- c(df[1:2],sapply(df[3:length(df)], function(x) stri_reverse[[x]]))

stri_reverse[[x]] 中的错误：“闭包”类型的对象不是子集

【问题讨论】：

df[-c(1,2)] <- t(apply(df[-1], 1, function(x) replace(x[-1], x[1] == stri_reverse(x[-1]), x[1])))

标签： r dataframe apply sapply

【解决方案1】：

错误来自您尝试使用[[ 对函数stri_reverse 进行子集化（可能是拼写错误？）；此外，您还需要稍微调整逻辑以获得所需的内容：

library(stringi)

df[-c(1,2)] <- lapply(df[-c(1,2)], function(col) {
    rev_col = stri_reverse(col)
    ifelse(rev_col == df$ref, rev_col, col)
})

df
#  number ref s1 s2 s3 s4 s5 s6
#1    rs1  AG AG AA GG AG AA AA
#2    rs2  AG AG GG AG GG GG AG
#3    rs3  AG AG AG GG AG AG GG
#4    rs4  AG AG AA AA AA GG AG
#5    rs5  AC AC AA CC AA AA AA
#6    rs6  AC AA AC AC CC CC CC

【讨论】：