list

#create a numeric vector
vector1<-rep(1,10)
vector1
 #[1] 1 1 1 1 1 1 1 1 1 1

#create a character vector - 'letters' and 'LETTERS' are predefined in R
vector2<-letters[1:7]
vector2
#[1] "a" "b" "c" "d" "e"

#create list of two vectors
L1=list(vector1,vector2)

#Accessing elements of a list
L1[[1]]

# [1] 1 1 1 1 1 1 1 1 1 1

L1[[2]]
#[1] "a" "b" "c" "d" "e"


#Creating list dynamically
L2<-list();L2
#list()

L2[[1]]<-vector1; L2[[1]]
# [1] 1 1 1 1 1 1 1 1 1 1

L2[[2]]<-vector2; L2[[1]]
# [1] 1 1 1 1 1 1 1 1 1 1

L2[[2]]
#[1] "a" "b" "c" "d" "e"

#accessing an element in the list
L2[[2]]
#[1] "a" "b" "c" "d" "e"

L2[[2]][2]
#[1] "b"

#creating list with names of elements
L3=list(vector1=vector1,vector2=vector2)
L3$vector1
 #[1] 1 1 1 1 1 1 1 1 1 1

L3$vector2
#[1] "a" "b" "c" "d" "e"

L3$vector1
 #[1] 1 1 1 1 1 1 1 1 1 1

#storing matrix in a list
mat1<-matrix(seq(1:10),2,5)
mat1
#     [,1] [,2] [,3] [,4] [,5]
#[1,]    1    3    5    7    9
#[2,]    2    4    6    8   10
L4=list(vector1=vector1,mat1=mat1)
L4$vector1
# [1] 1 1 1 1 1 1 1 1 1 1

L4$mat1
 #    [,1] [,2] [,3] [,4] [,5]
#[1,]    1    3    5    7    9
#[2,]    2    4    6    8   10

#storing a data frame in a list
mat2<-data.frame(mat1)
mat2
#  X1 X2 X3 X4 X5
# 1  1  3  5  7  9
# 2  2  4  6  8 10
L4=list(vector1=vector1,mat2=mat2)
L4$vector1
# [1] 1 1 1 1 1 1 1 1 1 1

L4$mat2
#  X1 X2 X3 X4 X5
#  1  1  3  5  7  9
#  2  2  4  6  8 10

#length of list
length(L4)
#[1] 2

#names of elements
names(L4)
#[1] "vector1" "mat2"

#change names of list elements
names(L4)[2]<-'mat'
names(L4)
#[1] "vector1" "mat"