我正在使用NCBI参考序列登录号,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,我需要在入藏号后删除.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,这不是这个变量的正确方法。谁能帮我这个?
你只需要逃避这段时间:
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"
我们可以假装它们是文件名并删除扩展名:
tools::file_path_sans_ext(a)
# [1] "NM_020506" "NM_020519" "NM_001030297" "NM_010281" "NM_011419" "NM_053155"
你可以这样做:
sub("*\\.[0-9]", "", a)
要么
library(stringr)
str_sub(a, start=1, end=-3)
如果字符串应该是固定长度,那么可以使用来自substr
的base R
。但是,我们可以用.
获得regexpr
的位置并在substr
中使用它
substr(a, 1, regexpr("\\.", a)-1)
#[1] "NM_020506" "NM_020519" "NM_001030297" "NM_010281" "NM_011419" "NM_053155"