数据存储
1)
保存为简单的文本文件
write.table(d,file = "c:/data/foo.txt",row.names = F, quote = F)
2)
保存为逗号分割的文本文件
write.csv(d, file ="c:/data/foo.csv",row.names = F, quote = F)
3)
保存为
R
格式文件
save(d, file = "c:/data/foo.Rdata")
4)
保存工作空间
镜像
>save.image( ) = save(list =ls(all=TRUE),file=".RData")
文件读取
1)read.table( )
>HousePrice <- read.table(file="houses.dat")如果明确数据第一行做表头,则使用header选项
>HousePrice <- read.table("houses.dat", header=TRUE)
read.table( ) 变形有: read.csv( ),read.csv2( ), read.delim( ),read.delim2( ).
前两个读取逗号分割数据,后两个读取其他分割符数据。
2)scan( ) :可以指定变量的类型
> mydata <- scan("C:/Desktop/data.dat", what = list("", 0, 0)) Read 4 records > print(mydata) [[1]] [1] "M" "M" "F" "F" [[2]] [1] 65 70 54 58 [[3]] [1] 168 172 156 163
> mydata <- scan("C:/Desktop/data.dat", what = list(Sex="", Weight=0, Height=0)) Read 4 records > print(mydata) $Sex [1] "M" "M" "F" "F" $Weight [1] 65 70 54 58 $Height [1] 168 172 156 163
3)read.fwf( ):读取文件中一些固定宽度数据
> mydata <- read.fwf("C:/Desktop/data.txt", widths=c(1, 4, 3), col.names=c("X","Y","Z")) > mydata X Y Z 1 A 1.50 1.2 2 A 1.55 1.3 3 B 1.60 1.4
tips:
Warning message:
In readLines(file, n = thisblock) :
读'C:/Users/baixuezhuo/Desktop/data.txt'时最后一行未遂
文件最后一行换行!
4)readLines()
> con <- file("C:/Desktop/data.csv", "r") > lineCnt = 0 > while(1){ + oneline = readLines(con, n = 1) + if(length(oneline) == 0){ + break + } + lineCnt = lineCnt+1 + } > close(con)完全不懂!
链接: R语言输出函数