data=C()

seq(from=,to=,by=n) generates an arithmetic sequence within a certain range

rep(x=,time=) repeats a certain number

name

Generate statistically distributed random numbers

data[n]

any(data>x)=T/F

all(data<x)=T/F

data[data>n]=data1, data*data=T/F

ifelse(data==n, n,n) performs vectorized filtering on vectors

subset(data,data>n) automatically selects non-NA qualified values

which(data>n) returns the position index of the qualified value

data[T/F,] performs Boolean operations on indexes

create

increase

delete

check

dim(data) Number of rows and columns of matrix

data=list(""=name,...) tags-datas

data=c(list(list(),list()),list(),recursive=T/F) Whether to flatten the list recursively

data$a, data[["a"]] data[[i]] data[i] query a certain component

data[n:n]

len(data)

Delete by part name

delete by index

data$new<-data

The two components of the data frame correspond one to one and assign factors to each other.

data=factor(data,levels=c(),orders=T/F)

tapply(vector, list(vextor1, vextor2),f())

splite(datafame, list(vector1, vector2)) is classified according to two conditions

table(data)

level

data