1-R语言与统计分析.pptx

R语言与统计分析;2;3;R与统计简介; ;6;7;8;9;10;11;12;13;14;15;16;17;18;19;20;21;22;23;24;25;26;27;28;29;30;数据的读入;setwd(D:/R语言与统计分析课程课件) data=read.csv(beer.csv,na.strings= ,header=T,sep=,) write.table(data, file = data1.txt, row.names = F, quote = F) data2=read.table( data1.txt,header=TRUE) write.csv(data2, file=data2.csv,row.names=F) save(data2, file=data2.Rdata) ;objects() 被用来显示目前存储在R中的对象的名字。而当前存 储的所有对象的组合被称为workspace。 清除对象可以使用rm命令： 所有在一个R任务中被创建的对象都可以在文件中被永久保存，并在其 它的R任务中被使用。在每个R任务结束时用户都有机会保存当前有效的 所有对象。如果用户这样做的话，对象将被写入当前目录一个名为.RData ***Note3***。当R被再次启动时R会从这个文件中再载入workspace。同时 相关的命令记录也被载入。;If your data set did not have a header, R has provided some attributes for it, namely “V1”, “V2”, “V3”, “V4” and “V5”. data=read.csv(beer.csv,na.strings= ,header=F, sep=,) data=read.csv(beer.csv,na.strings= ,header=F, sep=,“, col.names=B1 B2 B3 B4) read.table 和 read.csv的用法总结 The separator symbol; The header argument is always set at?TRUE, which indicates that the first line of the file being read contains the header with the variable names; The?fill?argument is also set as?TRUE, which means that if rows have unequal length, blank fields will be added implicitly. ;read.table(file, header = FALSE, sep = , quote = \, dec = ., row.names, col.names, as.is = !stringsAsFactors, na.strings = NA, colClasses = NA, nrows = -1, skip = 0, check.names = TRUE, fill = !blank.lines.skip, strip.white = FALSE, blank.lines.skip = TRUE, comment.char = #, allowEscapes = FALSE, flush = FALSE, stringsAsFactors = default.stringsAsFactors(), fileEncoding = , encoding = unknown, text) ;read.csv() and read.csv2() The?read.csv()?and?read.csv2()?functions are frequently used to read spreadsheets saved with the extension?.csv?or Comma Separated Values. As described before,?read.csv()?and?read.csv2()?have another separator symbol: for the former this is a comma, whereas the latter uses a semicolon(“;”).? Remember?that both functions have the?header?and?fill?arguments set as?TRUE?by default.