查看DNA序列各碱基数目

rm(list = ls())
data_dna = readLines("sample_data.txt")
data_dna
library(stringr)
str_count(data_dna,c("A","T","G","C"))

##还可以用strsplit，再用table统计各碱基个数
dd = strsplit(data_dna,"")[[1]]
dd
table(dd)