R语言数据读入

Posted 2021-04-18 生信小猪

1、把数据写入用read.table()

read.table(file,header=FALSE,sep="",quote="\",dec=".",row.names,col.names,as.is=FALSE,na.strings="NA",colClasses=NA,nrows=-1,skip=0,check.names=TRUE,file=!blank.lines.skip,strip.white=FALSE,blank.lines.skip=TRUE,comment.char="#")
#为了避免每次都写绝对路径，可以用setwd()函数设置工作路径setwd("路径")注意：R读取的文件都是文本文件，不然R需要专门的包才可以读想要注释行原样的读进来     commment.char = "",check.names=FALSE

colnames(A) <- C（"x1","x2","x3")  #给文件A的列改列名为x1,x2,x3rowSums(A) #计算A的每一行的和colSums(A)  #计算A的每一列的和rowMeans(A)  #计算A的每一行的平均值colMeans(A)  #计算A的每一列的平均值str(A)  #查看A的每一列类型

#将新数据添加到数据框中c$sum <- c(d)  #给c数据框加上一列d,加上的这一列自己取名为sumc <- c[,-2]  #删除c数据框的第二列

#带有分组的数据deg<-read.table("DEG.txt",header=TRUE,comment.char="",sep = "\t",check.names=FALSE,row.names=1)head(deg)str(deg)
deg<-read.table("DEG.txt",header=TRUE,comment.char="",sep = "\t",check.names=FALSE,row.names=1,stringsAsFactors=FALSE)head(deg)str(deg)

#数据的写出#读入数据myfpkm<-read.table("All_gene_fpkm.txt",header=TRUE,comment.char="",sep = "\t",check.names=FALSE,row.names=1)nrow(myfpkm)#筛选数据,更多数据筛选方法可参考：http://www.omicsclass.com/article/83myfpkm<-myfpkm[rowSums(myfpkm)>1,]nrow(myfpkm)getwd()write.table(myfpkm,file = "filtered_fpkm.txt",quote = FALSE,sep = "\t")

#根据ID筛选数据子集myfpkm<-read.table("All_gene_fpkm.txt",header=TRUE,comment.char="",sep = "\t",check.names=FALSE,row.names=1)nrow(myfpkm)
id.list<-read.table("id.txt",header=F)
id.fpkm<-myfpkm[rownames(myfpkm) %in% id.list$V1,]

#合并数据student<-data.frame(ID=c(11,12,13),Name=c("Devin","Edward","Wenli"),Gender=c("M","M","F"),Birthdate=c("1984-12-29","1983-5-6","1986-8-8"))studentscore<-data.frame(SID=c(11,11,13),Course=c("Math","English","Chinese"),Score=c(90,80,95))score
str(score)
cbind(student,score)rbind(student,score)
student<-data.frame(ID=c(11,12,13),Name=c("Devin","Edward","Wenli"),Birthdate=c("1984-12-29","1983-5-6","1986-8-8"))student
rbind(student,score)

#mergestudent<-data.frame(ID=c(11,12,13),Name=c("Devin","Edward","Wenli"),Gender=c("M","M","F"),Birthdate=c("1984-12-29","1983-5-6","1986-8-8"))studentscore<-data.frame(SID=c(11,11,12,12,13),Course=c("Math","English","Math","Chinese","Math"),Score=c(90,80,80,95,96))score
result<-merge(student,score,by.x="ID",by.y="SID")result

2、把数据写出用write.table()

x  要写出的变量

append=FALSE   如果这个文件不在，会自动帮你创建

quote=TRUE  把输出的每一个数据加上一个引号，一把不希望加上，所以这里常设置为FALSE

sep=" "  默认不同的列用空格分开，一般情况设置为Tab键

write.table(x,file="",append=FALSE,quote=TRUE,sep=" ",ecol="\n",na="NA",dec=".",row.names=TRUE,col.names=TRUE,qmethod=c("escape","double"))