r - 从R中的data.frame中删除整列(Remove an entire column from a data.frame in R)

Question

Does anyone know how to remove an entire column from a data.frame in R?

(有谁知道如何从R中的data.frame中删除整个列？)

For example if I am given this data.frame:

(例如，如果我得到此data.frame：)

> head(data)
   chr       genome region
1 chr1 hg19_refGene    CDS
2 chr1 hg19_refGene   exon
3 chr1 hg19_refGene    CDS
4 chr1 hg19_refGene   exon
5 chr1 hg19_refGene    CDS
6 chr1 hg19_refGene   exon

and I want to remove the 2nd column.

(我想删除第二列。)

  ask by Nanami translate from so

Answer 1

You can set it to NULL .

(您可以将其设置为NULL 。)

> Data$genome <- NULL
> head(Data)
   chr region
1 chr1    CDS
2 chr1   exon
3 chr1    CDS
4 chr1   exon
5 chr1    CDS
6 chr1   exon

As pointed out in the comments, here are some other possibilities:

(正如评论中指出的那样，这里还有其他一些可能性：)

Data[2] <- NULL    # Wojciech Sobala
Data[[2]] <- NULL  # same as above
Data <- Data[,-2]  # Ian Fellows
Data <- Data[-2]   # same as above

You can remove multiple columns via:

(您可以通过以下方式删除多列：)

Data[1:2] <- list(NULL)  # Marek
Data[1:2] <- NULL        # does not work!

Be careful with matrix-subsetting though, as you can end up with a vector:

(但是，请谨慎使用矩阵子集，因为您可能会得到一个向量：)

Data <- Data[,-(2:3)]             # vector
Data <- Data[,-(2:3),drop=FALSE]  # still a data.frame