Regex 如何复制列名，在分隔符处拆分列名'/'；，转换为多个列名，在R？

我有一个矩阵（它的大小很大）“mymat”。我需要复制列名中与“/”匹配的列，并生成一个“resmatrix”。我怎样才能在R中完成这项工作

麦马特

resmatrix

 a   b   IID:WE:G12D   IID:WE:G12V    GH:SQ:p.R172W    GH:SQ:p.R172G   c
 1   3             4             4                2                2   4
22   4             2             2                2                2   4
 2   3             2             2                2                2   4

---

找出哪些列具有“/”并复制它们，然后重命名。要计算新名称，只需在

/

上拆分，并将最后一个字母替换为第二个名称

# which columns have '/' in them?
which.slash <- grep('/', names(mymat), value=T)
new.names <- unlist(lapply(strsplit(which.slash, '/'),
       function (bits) {
         # bits[1] is e.g. IID:WE:G12D and bits[2] is the V
         # take bits[1] and replace the last letter for the second colname
         c(bits[1], sub('.$', bits[2], bits[1]))
       }))

# make resmat by copying the appropriate columns
resmat <- cbind(mymat, mymat[, which.slash])
# order the columns to make sure the names replace properly
resmat <- resmat[, order(names(resmat))]
# put the new names in
names(resmat)[grep('/', names(resmat))] <- sort(new.names)

---

找出哪些列具有“/”并复制它们，然后重命名。要计算新名称，只需在

/

上拆分，并将最后一个字母替换为第二个名称

# which columns have '/' in them?
which.slash <- grep('/', names(mymat), value=T)
new.names <- unlist(lapply(strsplit(which.slash, '/'),
       function (bits) {
         # bits[1] is e.g. IID:WE:G12D and bits[2] is the V
         # take bits[1] and replace the last letter for the second colname
         c(bits[1], sub('.$', bits[2], bits[1]))
       }))

# make resmat by copying the appropriate columns
resmat <- cbind(mymat, mymat[, which.slash])
# order the columns to make sure the names replace properly
resmat <- resmat[, order(names(resmat))]
# put the new names in
names(resmat)[grep('/', names(resmat))] <- sort(new.names)

---

您可以使用

grep

获取具有

/

（'nm1'）的列名索引，通过使用

sub/scan

复制'nm1'中的列名以创建'nm2'。然后，

cbind

将非“nm1”的列与复制列（“nm1”）一起更改为“nm2”的列名，并在需要时对列进行排序

 #get the column index with grep
 nm1 <- grepl('/', names(df1))
 #used regex to rearrange the substrings in the nm1 column names
 #removed the `/` and use `scan` to split at the space delimiter
 nm2 <- scan(text=gsub('([^/]+)(.)/(.*)', '\\1\\2 \\1\\3', 
           names(df1)[nm1]), what='', quiet=TRUE)
 #cbind the columns that are not in nm1, with the replicate nm1 columns 
 df2 <- cbind(df1[!nm1], setNames(df1[rep(which(nm1), each= 2)], nm2))
 #create another index to find the starting position of nm1 columns
 nm3 <- names(df1)[1:(which(nm1)[1L]-1)] 
 #we concatenate the nm3, nm2, and the rest of the columns to match 
 #the expected output order
 df2N <- df2[c(nm3, nm2, setdiff(names(df1)[!nm1], nm3))]
 df2N 
 #   a b IID:WE:G12D IID:WE:G12V GH:SQ:p.R172W GH:SQ:p.R172G c
 #1  1 3           4           4             2             2 4
 #2 22 4           2           2             2             2 4
 #3  2 3           2           2             2             2 4

#使用grep获取列索引
nm1您可以使用
grep
获取具有
/
（'nm1'）的列名索引，使用
sub/scan
复制'nm1'中的列名以创建'nm2'。然后，
cbind
将非“nm1”的列与复制列（“nm1”）一起更改为“nm2”的列名，并在需要时对列进行排序

 #get the column index with grep
 nm1 <- grepl('/', names(df1))
 #used regex to rearrange the substrings in the nm1 column names
 #removed the `/` and use `scan` to split at the space delimiter
 nm2 <- scan(text=gsub('([^/]+)(.)/(.*)', '\\1\\2 \\1\\3', 
           names(df1)[nm1]), what='', quiet=TRUE)
 #cbind the columns that are not in nm1, with the replicate nm1 columns 
 df2 <- cbind(df1[!nm1], setNames(df1[rep(which(nm1), each= 2)], nm2))
 #create another index to find the starting position of nm1 columns
 nm3 <- names(df1)[1:(which(nm1)[1L]-1)] 
 #we concatenate the nm3, nm2, and the rest of the columns to match 
 #the expected output order
 df2N <- df2[c(nm3, nm2, setdiff(names(df1)[!nm1], nm3))]
 df2N 
 #   a b IID:WE:G12D IID:WE:G12V GH:SQ:p.R172W GH:SQ:p.R172G c
 #1  1 3           4           4             2             2 4
 #2 22 4           2           2             2             2 4
 #3  2 3           2           2             2             2 4

#使用grep获取列索引
nm1
df1 <-  structure(list(a = c(1L, 22L, 2L), b = c(3L, 4L, 3L),
`IID:WE:G12D/V` = c(4L, 
2L, 2L), `GH:SQ:p.R172W/G` = c(2L, 2L, 2L), c = c(4L, 4L, 4L)),
.Names = c("a", "b", "IID:WE:G12D/V", "GH:SQ:p.R172W/G", "c"),
class = "data.frame", row.names = c(NA, -3L))