R language-Input and output

Basic input and output

Input:

ReadLine, edit, Fix

Output:

Print, Cat

Output redirection

Sink

#basic input and outputx=ReadLine('Please enter:')#read input, one behavior of a stringX#[1] "1 2 3"MyData=data.frame (Name=character (0), Age=numeric (0), Height=numeric (0))#defining domain types by character (0)Mydata=edit (MyData)#modify directly with editMydatamydata2=data.frame ()#Create an empty data.frameMydata2=edit (MYDATA2) Mydata2fix (MYDATA2)#modify directly by fixMydata2#Output Print CatX=rnorm (Ten, -,2)  Print(x)#The print output has a newline at the end and an element position hint at the beginning of the lineCat (x)#cat output is not wrapped, orderedPrint(X,digits =4)#valid bitsPrint('Hello World 1') ;Print('Welcome to R') Cat ('Hello World 1'); Cat ('Welcome to R') Cat (format(x,digits=3),'\ n')#specify a valid bit by formatCat ('Hello World', file='D:/app.log')#REDIRECT sinkSink'output.txt', append = T)#Append mode redirectionPrint('Hello World') sink ()#Sink () required after useSink'D:/output.txt') Cat ('Hello world \ n') Cat (x,'\ n') sink () x=rnorm (Ten) xPrint(x,digits=2) getOption ('digits')#Get digits option information defaults to 7Options (digits =7)#modifying option informationX

Analog Data and datasets

#analog Data and Datasets # arbitrary distribution # y=a*x+b+e# X~n (0,2) # e~n (0,1) # b=0.5, a=2Set. Seed (Ten)#random seeds start with the same random seed, and the result of subsequent random numbers is the same.X=rnorm ( -,0,2) e=rnorm ( -) y=2*x +0.5+Eplot (x,y)#Generate random numbers(X=rbinom (5, -,0.7)) (x=rbinom (5, -,0.7)) Set. Seed (Ten) (x=rbinom (5, -,0.7)) (x=rbinom (5, -,0.7)) Data ( Package='Datasets')#Data ()##查看系统所有包中的数据集Data Package=.packages (all.available =T)) Library (Arules)#Load PackageData (groceries)#Querying data sets

File Data source

Text file:

Read.table, Read.csv, Read.delim

Excel file:

Multiple ways

SPSS file:

FOREIGN::READ.SPSS, Hmisc::spss.get

#File Data SourceGETWD ()#get current work pathSETWD ('e:/')#Modify the current work pathx=rnorm ( +,Ten,2) y=rnorm ( +,Ten,2) Z=rnorm ( +,Ten,2) Save (x, y,z,file='XYZ. Rdata')#Save saves the file while saving the variable informationL=load ('XYZ. Rdata')#Load load file, load variable informationx=Read. Table ('Scan0.txt', header=t,sep=' ', Comment.char ='@')#reading text Filesxstr (x) x=Read. CSV ('Scan0.txt', Header=f,comment.char ='@', sep=' ')#Read CSV fileSTR (x) x=Read. Delim ('Scan.txt', header=f,sep=' ') x=Read. Delim ('Clipboard', header=f)#reading clipboard informationx=scan ('Scan.txt', What=list (date="", pv=0, uv=0), sep=",")#What specifies the data type specify list name and data type via listx=as.data.frame (x)Write. Table (x,'Scan2.txt', sep=',', quote=f,col.names = t,row.names=f)#Write files #excel file # 1, CSV file # 2, clipboard +read.delim# 3, xlsx expansion Pack # 4, RODBC data sourceLibrary (foreign) cars=Read. SPSS ('Car_sales.sav') Library (HMISC) Cust=spss.get ('Car_sales.sav', Use. Value.labels =T) Cust

relational database MySQL

ODBC, Rmysql

#RmysqlInstall.packages ('Rmysql') Library (RMYSQL) Conn= Dbconnect (MySQL (), dbname='rtest', username='rtest', password='rtest', host="192.168.1.100", port=3306) dblisttables (conn) dblistfields (Conn,'T_user') Summary (MySQL (), verbose=T) Users=dbreadtable (Conn,'T_user') str (users) Userstmpuser=data.frame (Name=paste ('User',1: -, sep="'), Age=rnorm ( -, -,5)) tmpuserdbwritetable (Conn,'T_user', tmpuser,append=t,row.names=FALSE) dbwritetable (Conn,'T_stu', tmpuser,append=T) dbreadtable (Conn,'T_stu') Res=dbgetquery (Conn,'SELECT * from T_user where age>10') Resres=dbsendquery (Conn,'Show Databases')#Records and TypesDl=Fetch (RES) DLDBDISCONNECT (conn)#RODBCInstall.packages ('RODBC') Library (RODBC) Conn=odbcconnect ("Mysqlodbc") Conn=odbcconnect ("Mysqlodbc", uid="rtest", pwd='rtest') sqlTables (conn) Users=sqlfetch (Conn,'T_user') usersstr (users) Users=sqlquery (Conn,'SELECT * from T_user where age>15') Usersodbcclose (conn)

R language-Input and output