1. 按照列
dat$V1[which(dat$V1 =='Repressor')] <- 'Silent'
## 將第一列是Repressor的替換為Silent
dat <- dat[grep(pattern = "chr",dat[,1]),]
## 篩選第一列是chr開頭的所有行
dat$V1[which(dat$V1 =='Repressor')] <- 'Silent'
## 將第一列是Repressor的替換為Silent
dat <- dat[grep(pattern = "chr",dat[,1]),]
## 篩選第一列是chr開頭的所有行