16 Data Frames functions and $ symbol in R language

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wbvlr<-read.csv("gd.csv")
wbvlr
nrow(wbvlr)
ncol(wbvlr)
head(wbvlr)
tail(wbvlr)
head(wbvlr,n=10)
tail(wbvlr,n=1)
?str()
#Interview
str(wbvlr)
summary(wbvlr)
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head(wbvlr)
wbvlr[1,3]
wbvlr[,3]
wbvlr[2,]
wbvlr[c(1,2,9),]
wbvlr[2,"Income.Group"]
wbvlr[,3]
wbvlr$
wbvlr$Income.Group
wbvlr$Country.Name
wbvlr$Country.Name[3]
wbvlr$Income.Group

levels(wbvlr$Income.Group)
levels(wbvlr$Country.Name)
levels(wbvlr$Internet.users)
head(wbvlr)