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1、第七讲 导入导出数据,导入数据,read.table()scan(),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,fill=!,strip.white=FALSE,=TRUE,comment.char=#),team,name,level,worktime,bounsbatch,SuNan,B,135,9,818batch,ChenQi,E,121,6,050b
2、atch,JiangXu,F,97,4,189online,ZhouXi,F,63,online,ChenHe,H,36,1,064,例子：TeamInfo.csv,read.table(D:/work/TeamInfo.csv,header=TRUE,sep=,)-TeamInfo TeamInfo team name level worktime bouns1 batch SuNan B 135 9,8182 batch ChenQi E 121 6,0503 batch JiangXu F 97 4,1894 online ZhouXi F 63 5 online ChenHe H 36
3、 1,064,file:“”,文件名的绝对路径，或工作目录下的文件,setwd(D:/work)getwd()1 D:/work read.table(TeamInfo.csv,header=TRUE,sep=,)-TeamInfo,head：TRUE，第一行为数据名；FALSE（缺省），第一行被命名为V1,V2,read.table(D:/work/TeamInfo.csv,header=FALSE,sep=,)-TeamInfo TeamInfo V1 V2 V3 V4 V51 team name level worktime bouns2 batch SuNan B 135 9,8183
4、 batch ChenQi E 121 6,0504 batch JiangXu F 97 4,1895 online ZhouXi F 63 6 online ChenHe H 36 1,064,read.table(D:/work/TeamInfo.csv,header=TRUE,sep=)-TeamInfo TeamInfo 1 batch,SuNan,B,135,9,8182 batch,ChenQi,E,121,6,0503 batch,JiangXu,F,97,4,1894 online,ZhouXi,F,63,5 online,ChenHe,H,36,1,064,sep:字段分割
5、符号“”任意空格“,”逗号分割 cammo seperated values“t”tab,nrows=-1：可读取的最大行数skip=0：跳过的行数,read.table(D:/work/TeamInfo.csv,header=TRUE,sep=,nrows=3,skip=0)-TeamInfo TeamInfo team name level worktime bouns1 batch SuNan B 135 9,8182 batch ChenQi E 121 6,0503 batch JiangXu F 97 4,189,read.table(D:/work/TeamInfo.csv,he
6、ader=TRUE,sep=,nrows=3,skip=2)-TeamInfo TeamInfo batch ChenQi E X121 X6.0501 batch JiangXu F 97 4,1892 online ZhouXi F 63 3 online ChenHe H 36 1,064,read.table的几个变种因为使用了不同的缺省值可以用在几种不同情况下：read.csv(file,header=TRUE,sep=,quote=,dec=.,fill=TRUE,.)read.csv2(file,header=TRUE,sep=;,quote=,dec=,fill=TRUE,.)
7、read.delim(file,header=TRUE,sep=t,quote=,dec=.,fill=TRUE,.)read.delim2(file,header=TRUE,sep=t,quote=,dec=,fill=TRUE,.),内建数据集的存取,data()#获得基本系统提供的数据集列表data(cars)#来载入名为cars的数据集cars#直接调用,从其他R功能包中载入数据,方式一、data(package=“affy)data(mapCdfName,package=“affy)方式二 library(Animal)data()data(RIC),数据编辑,average-edi
8、t(averageAEP)xnew-edit(data.frame(),scan(file=,what=double(0),nmax=-1,n=-1,sep=,quote=if(sep=n)else,dec=.,skip=0,nlines=0,na.strings=NA,flush=FALSE,fill=FALSE,strip.white=FALSE,quiet=FALSE,=TRUE,multi.line=TRUE,comment.char=),scan(D:/work/TeamInfo.csv,what=list(team=,name=,level=,worktime=0,bouns=),
9、skip=1,sep=,)-TeamInfoRead 5 records TeamInfo$team1 batch batch batch online online$name1 SuNan ChenQi JiangXu ZhouXi ChenHe$level1 B E F F H$worktime1 135 121 97 63 36$bouns1 9,818 6,050 4,189 1,064,例子：从average AEP.csv中第10行后读取100个数据,scan(D:/work/average AEP.csv,n=100,sep=,skip=10)-averageAEPRead 10
10、0 itemsx-matrix(averageAEP,nrow=20),scan(D:/work/average AEP.csv,what=list(first=numeric,second=numeric),nmax=100,sep=,skip=10)-averageAEPRead 102 recordsscan(D:/work/average AEP.csv,what=list(first=numeric,second=numeric),nmax=10,sep=,skip=10)-averageAEPRead 17 records,从键盘输入数据,file=“”时从键盘输入Ctrl+Z 输
11、入结束,scan(file=)-input,scan(file=,what=list(first=numeric,second=numeric),nmax=10)-input,练习7.1,以两中方式读取文件average AEP.csv的第60180行，并以赋值给一矩阵。,导出数据,write.table()cat(),write.table(x,file=,append=FALSE,quote=TRUE,sep=,eol=n,na=NA,dec=.,row.names=TRUE,col.names=TRUE,qmethod=c(escape,double),write.table(x,D:/
12、work/average.csv),File:绝对路径或工作目录下文件，缺省时在控制台输出,write.table(x,D:/work/aver.csv,col.names=c(V1,V2,V3,V4,V5),row.names=LETTERS1:20,sep=,),scan(D:/work/average AEP.csv,n=100,sep=,skip=10)-averageAEPRead 100 itemsx-matrix(averageAEP,nrow=20),cat(),cat(TITLE extra line,2 3 5 7,11 13 17,file=D:/work/ex.csv,
13、sep=,append=TRUE)cat(x,file=D:/work/aver.csv,sep=,append=TRUE)cat(x,file=D:/work/aver.csv,n,sep=,append=TRUE),格式化输出,formatC(x,#数值向量、字符向量等digits=NULL,#指定有效位数或小数点后的位数width=NULL,#指定输出宽度format=NULL,#”d”整数、”f”定点实数、”e”科学计数flag=“”,#指定一个输出选项字符串：“-”表示左右#对齐；“0”表示左空白用0填充；“+”表示输出正负号mode=NULL,big.mark=,big.inter
14、val=3,small.mark=,small.interval=5,decimal.mark=.),ToYYMMDD-function(r)cat(formatC(r1,format=d,width=2,flag=0),-,formatC(r2,format=d,width=2,flag=0),-,formatC(r3,format=d,width=2,flag=0),n,sep=)Birthday-rbind(c(72,1,7),c(75,6,7)apply(Birthday,1,ToYYMMDD),例子：以YY-MM-DD格式输出生日时间,练习7.2,第一步：通过scan()函数读取average AEP.csv文件，并转化为矩阵averAEPscan(D:/work/average AEP.csv,sep=,skip=10)-averageAEPaverAEP-matrix(averageAEP,ncol=17)第二步：利用cat()函数把矩阵averAEP保存为csv文件，要求保持行列属性不变。,练习7.3,继续完成第六讲练习二，并把AEP波形极值数据以csv格式的文件保存,
