删除 "."之后的部分字符串

Question

我正在使用 NCBI 引用序列登录号，例如变量 a:

a <- c("NM_020506.1","NM_020519.1","NM_001030297.2","NM_010281.2","NM_011419.3", "NM_053155.2")  

要从 Biomart 包中获取信息，我需要删除登录号后面的 .1、.2 等。我通常使用以下代码执行此操作:

b <- sub("..*", "", a)

# [1] "" "" "" "" "" ""

但正如您所看到的，这不是该变量的正确方法。谁能帮我解决这个问题吗？

Answer 1

你只需要避开句点:

a <- c("NM_020506.1","NM_020519.1","NM_001030297.2","NM_010281.2","NM_011419.3", "NM_053155.2")

gsub("\\..*","",a)
[1] "NM_020506"    "NM_020519"    "NM_001030297" "NM_010281"    "NM_011419"    "NM_053155"