如何提取部分名称作为数据框中的新列名称

Question

I have a data frame as below. I would like to take a part of column name as new name since it was too long and not necessary to me. Thanks for any helps.

df = read.table(text="PV_556933.C25E8ACXX.1.250197415   PD_556996.C25E8ACXX.1.250197421 PT_556997.MERGE PC_559379.D25PAACXX.2.250194617
G   G   G   G
A   A   A   A
A   A   A   A
G   G   G   T
C   T   C   T
A   A   A   A", header=T, stringsAsFactors=F)

I expect the data frame as:
PV_556933   PD_556996   PT_556997   PC_559379
G   G   G   G
A   A   A   A
A   A   A   A
G   G   G   T
C   T   C   T
A   A   A   A

Answer 1

How's this? I split the string ( strsplit ) at a dot (which you need to escape using \\\\ ) and take out only the first element using lapply . unlist is there to coerce the list into a vector.

> names(df) <- unlist(lapply(strsplit(names(df), "\\."), "[[", 1))
> df
  PV_556933 PD_556996 PT_556997 PC_559379
1         G         G         G         G
2         A         A         A         A
3         A         A         A         A
4         G         G         G         T
5         C         T         C         T
6         A         A         A         A