根据矢量中的* not *选择R数据帧中的列 [英] Selecting columns in R data frame based on those *not* in a vector

问题描述

我很熟悉如何从R数据框（或矩阵）中提取列：

  df .2 < -  df [，c（name1，name2，name3）] 
  

但是可以使用！或其他工具来选择列出的所有列？

对于背景，我有一个包含很多列向量的数据框，我想避免：

• 输出大部分名字，当我可以删除少数


• 使用更短的 df.2 < - df [，c（1,3,5） ] 因为当我的.csv文件发生变化时，我的代码会因为编号不一样了。我是R的新人，认为我已经学会了不要使用数字向量来改变更大的df。

我试过：

  df.2 < -  df [，！c（name1，name2，name3 ）] 
 df.2 < -  df [，！= c（name1，name2，name3）] 
  

正如我输入的那样，发现这样做是有效的：

  df .2 < -  df [％]％c（name1，name2，name3）中的名称（df）％] 
  

有没有比最后一个更好的方法？

解决方案

c $ c> grep 是哪个：

  df.2 < -  df [， - 其中％c中的（df）％（name1，name2，name3））] 
  pre> 
I'm familiar with being able to extract columns from an R data frame (or matrix) like so:
df.2 <- df[, c("name1", "name2", "name3")]
But can one use a ! or other tool to select all but those listed columns?

For background, I have a data frame with quite a few column vectors and I'd like to avoid:


Typing out the majority of the names when I could just remove a minority
Using the much shorter df.2 <- df[, c(1,3,5)] because when my .csv file changes, my code goes to heck since the numbering isn't the same anymore. I'm new to R and think I've learned the hard way not to use number vectors for larger df's that might change.


I tried:
df.2 <- df[, !c("name1", "name2", "name3")]
df.2 <- df[, !=c("name1", "name2", "name3")]
And just as I was typing this, found out that this works:
df.2 <- df[, !names(df) %in% c("name1", "name2", "name3")]
Is there a better way than this last one?
解决方案
An alternative to grep is which:
df.2 <- df[, -which(names(df) %in% c("name1", "name2", "name3"))]


                        
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