[英]removing vectors from data frame by suffix in r
Some vectors in data frame have
include the suffix _rc_1
.数据框中的
have
向量包含后缀_rc_1
。 I want to remove these vectors from the data frame.我想从数据框中删除这些向量。 I've tried several options and get errors that show I'm misunderstanding something.
我已经尝试了几个选项,但得到的错误表明我误解了一些东西。 For example:
例如:
library(dplyr)
newdata <- subset(mydata, -contains("_rc_1"))
Error: No tidyselect variables were registered
I'm agnostic to how I solve the problem.我不知道我如何解决这个问题。
Perhaps this is done best with grepl()
and a regular expression, but I'm struggling to implement a version that performs as planned here as well.也许这最好用
grepl()
和正则表达式来完成,但我正在努力实现一个在这里也能按计划执行的版本。
contains
work with dplyr
If we need to use subset
(a base R
function), use grep
which can take regex pattern and return either a numeric index or the column names itself as select
argument in subset
can take both as valid inputs contains
work with dplyr
If we need to use subset
(a base R
function), use grep
which can take regex pattern and return either a numeric index or the column names itself as select
argument in subset
can take both as valid inputs
subset(mydata, select = grep("_rc_1", names(mydata), value = TRUE, invert = TRUE))
Also, there is startsWith/endsWith
in base R
for prefix/suffix matches此外,在
base R
中有用于前缀/后缀匹配的startsWith/endsWith
subset(mydata, select = names(mydata)[!endsWith(names(mydata), "_rc_1")])
In dplyr
, the select_helpers
- contains
works with select
在
dplyr
中, select_helpers
- contains
与select
一起使用
library(dplyr)
mydata %>%
select(-contains("_rc_1"))
Reproducible with built-in dataset 'iris'可使用内置数据集“iris”重现
data(iris)
head(subset(iris, select = names(iris)[!endsWith(names(iris), "Length")]))
iris %>%
select(-contains('Sepal')) %>%
head
In base R you can use grepl
to get a logical vector with length equal to ncol(mydata)
which is TRUE
for column names ending in _rc_1
(the $ ensures that _rc_1 comes at the end).在基础 R 中,您可以使用
grepl
获取长度等于 ncol ncol(mydata)
的逻辑向量,对于以_rc_1
结尾的列名,该向量为TRUE
($ 确保 _rc_1 出现在末尾)。 Then after swapping the TRUE
s and FALSE
s with !
然后将
TRUE
和FALSE
交换为!
, you can subset your data frame using []
. ,您可以使用
[]
对数据框进行子集化。
newdata <- mydata[!grepl('_rc_1$', names(mydata))]
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