Create a matrix from a list of vectors using R

In R, vectors can be integer, double, character, logical, complex and raw types. A vector is created using the c() function:

a <- c(val1, val2, ...

Creating a List of Vectors

A list of vectors in R is an array of more than one vector kept in a list structure. Creating a list of vectors is done in the following way:

[1] "The list of vectors is: "
[[1]]
[1] 1 2 3 4

[[2]]
[1] 2 3 4 5

[[3]]
[1] 3 4 5 6

[[4]]
[1] 4 5 6 7

[[5]]
[1] 5 6 7 8

Matrix from List of Vectors

Matrices in R can be formed from a list of vectors with the help of functions such as do.call() and matrix().

Using do.call() Function

do.call() helps you execute a function (such as rbind()) on a list of arguments. Here's how to use it to form a matrix:

Output:

[,1] [,2] [,3] [,4]
[1,] 1 2 3 4
[2,] 2 3 4 5
[3,] 3 4 5 6
[4,] 4 5 6 7
[5,] 5 6 7 8

we call the do.call() function and pass the arguments as rbind and a.

Using matrix() Function

The matrix() function is used to transform a list of vectors into a matrix. To accomplish this, we first transform the list into a single vector with unlist(), then form the matrix:

Syntax:

matrix(data, nrow, ncol, byrow, dimnames)

Where,

• data: is the input vector which represents the elements in the matrix
• nrow: specifies the number of rows to be created
• ncol: specifies the number of columns to be created
• byrow: specifies logical value. If TRUE, matrix will be filled by row. Default value is FALSE.
• dimnames: specifies the names of rows and columns

 [,1] [,2] [,3] [,4] [,5]
[1,] 1 2 3 4 5
[2,] 2 3 4 5 6
[3,] 3 4 5 6 7
[4,] 4 5 6 7 8
[5,] 5 6 7 8 9
[6,] 6 7 8 ...