如何在data.frame中重命名单个列?

I know if I have a data frame with more than 1 column, I can use

我知道如果我有一个超过一列的数据框架，我可以使用

colnames(x) <- c("col1","col2")

to rename the columns. How do I do this if it's just one column? Meaning a vector or data frame with only one column in it.

重命名列。如果只是一列，我怎么做呢?表示只有一列的向量或数据帧。

Example:

例子:

trSamp <- data.frame(sample(trainer$index, 10000))
head(trSamp )
#   sample.trainer.index..10000.
# 1                      5907862
# 2                      2181266
# 3                      7368504
# 4                      1949790
# 5                      3475174
# 6                      6062879

ncol(trSamp)
# [1] 1
class(trSamp)
# [1] "data.frame"
class(trSamp[1])
# [1] "data.frame"
class(trSamp[,1])
# [1] "numeric"
colnames(trSamp)[2] <- "newname2"
# Error in names(x) <- value : 
#   'names' attribute [2] must be the same length as the vector [1]

13 个解决方案

#1

232

colnames(trSamp)[2] <- "newname2"

attempts to set the second column's name. Your object only has one column, so the command throws an error. This should be sufficient:

尝试设置第二列的名称。对象只有一列，因此命令抛出一个错误。这应该是足够:

colnames(trSamp) <- "newname2"

#2

389

This is a generalized way in which you do not have to remember the exact location of the variable:

这是一种广义的方法，你不需要记住变量的确切位置:

# df = dataframe
# old.var.name = The name you don't like anymore
# new.var.name = The name you want to get

names(df)[names(df) == 'old.var.name'] <- 'new.var.name'

This code pretty much does the following:

这段代码大致如下:

names(df) looks into all the names in the df
names(df)检查df中的所有名称
[names(df) == old.var.name] extracts the variable name you want to check
[names(df) == old.var.name]提取要检查的变量名
<- 'new.var.name' assigns the new variable name.
<- 'new.var.name'分配新变量名。

#3

colnames(df)[colnames(df) == 'oldName'] <- 'newName'

#4

This is an old question, but it is worth noting that you can now use setnames from the data.table package.

这是一个老问题，但值得注意的是，您现在可以从数据中使用setnames。表方案。

library(data.table)

setnames(DF, "oldName", "newName")

# or since the data.frame in question is just one column: 
setnames(DF, "newName")

# And for reference's sake, in general (more than once column)
nms <- c("col1.name", "col2.name", etc...)
setnames(DF, nms)

#5

This can also be done using Hadley's plyr package, and the rename function.

这也可以使用Hadley的plyr包和rename函数来完成。

library(plyr) 
df <- data.frame(foo=rnorm(1000)) 
df <- rename(df,c('foo'='samples'))

You can rename by the name (without knowing the position) and perform multiple renames at once. After doing a merge, for example, you might end up with:

您可以通过名称重命名(不知道位置)并同时执行多个重命名。例如，在进行合并之后，您可能会得到:

  letterid id.x id.y
1       70    2    1
2      116    6    5
3      116    6    4
4      116    6    3
5      766   14    9
6      766   14   13

Which you can then rename in one step using:

你可以用一个步骤重命名:

letters <- rename(letters,c("id.x" = "source", "id.y" = "target"))

  letterid source target
1       70      2      1
2      116      6      5
3      116      6      4
4      116      6      3
5      766     14      9
6      766     14     13

#6

I think the best way of renaming columns is by using the dplyr package like this:

我认为重命名列的最好方法是使用dplyr包，如下所示:

require(dplyr)
df = rename(df, new_col01 = old_col01, new_col02 = old_col02, ...)

It works the same for renaming one or many columns in any dataset.

它对在任何数据集中重命名一个或多个列都是一样的。

#7

I like the next style for rename dataframe column names one by one.

我喜欢重命名dataframe列名的下一个样式。

colnames(df)[which(colnames(df) == 'old_colname')] <- 'new_colname'

where

在哪里

which(colnames(df) == 'old_colname')

returns by the index of the specific column.

按特定列的索引返回。

#8

Try:

试一试:

colnames(x)[2] <- 'newname2'

#9

You can use the rename.vars in the gdata package.

您可以使用重命名。gdata包中的vars。

library(gdata)
df <- rename.vars(df, from = "oldname", to = "newname")

This is particularly useful where you have more than one variable name to change or you want to append or pre-pend some text to the variable names, then you can do something like:

当你有多个变量名需要更改，或者你想在变量名中添加或预先添加一些文本时，这是特别有用的，然后你可以做如下的事情:

df <- rename.vars(df, from = c("old1", "old2", "old3", 
         to = c("new1", "new2", "new3"))

For an example of appending text to a subset of variables names see: https://*.com/a/28870000/180892

有关将文本附加到变量名称子集的示例，请参见:https://*.com/a/28870000/180892

#10

If you know that your dataframe has only one column, you can use: names(trSamp) <- "newname2"

如果您知道您的dataframe只有一个列，您可以使用:names(trSamp) <- "newname2"

#11

You could also try 'upData' from 'Hmisc' package.

您也可以尝试“Hmisc”包中的“upData”。

library(Hmisc)

库(Hmisc)

trSamp = upData(trSamp, rename=c(sample.trainer.index..10000. = 'newname2'))

trSamp = upData(trSamp,重命名= c(sample.trainer.index . . 10000。= ' newname2 '))

#12

I find that the most convenient way to rename a single column is using dplyr::rename_at :

我发现重命名单个列最方便的方法是使用dplyr::rename_at:

library(dplyr)
cars %>% rename_at("speed",~"new") %>% head     
cars %>% rename_at(vars(speed),~"new") %>% head
cars %>% rename_at(1,~"new") %>% head

#   new dist
# 1   4    2
# 2   4   10
# 3   7    4
# 4   7   22
# 5   8   16
# 6   9   10

works well in pipe chaines
在管治中工作很好。
convenient when names are stored in variables
当名称存储在变量中时非常方便
works with a name or an column index
使用名称或列索引
clear and compact
清晰而紧凑的

#13

This is likely already out there, but I was playing with renaming fields while searching out a solution and tried this on a whim. Worked for my purposes.

这很可能已经存在了，但我在寻找解决方案时尝试重新命名字段，并心血来潮地尝试了一下。为我工作的目的。

Table1$FieldNewName <- Table1$FieldOldName
Table1$FieldOldName <- NULL

Edit begins here....

在这里编辑开始....

This works as well.

这个作品。

df <- rename(df, c("oldColName" = "newColName"))

#1

232

colnames(trSamp)[2] <- "newname2"