## R – Get Multiple Columns of Matrix

To get multiple columns of matrix, specify the column numbers as a vector preceded by a comma, in square brackets, after the matrix variable name. This expression returns the required columns as a matrix.

In this tutorial, we will learn how to get a multiple columns from a Matrix, with examples.

### Syntax

The syntax of the expression to get multiple columns at given vector of positions/indices in a matrix is

`X[, columns]`

where

Return Value

The expression returns the selected columns as a matrix from matrix `X` at given `columns` numbers.

### Examples

In the following program, we create a matrix and get the columns at position `1` and `3`. We pass the vector `c(1, 3)` for the `columns` in the expression `X[, columns]`.

example.R

```data <- c(2, 4, 7, 5, 10, 8, 1, 3)
A <- matrix(data, nrow = 2)
columns <- A[, c(1, 3)]

print("Matrix A")
print(A)
print("Selected Columns")
print(columns)```

Output

``` "Matrix A"
[,1] [,2] [,3] [,4]
[1,]    2    7   10    1
[2,]    4    5    8    3
 "Selected Columns"
[,1] [,2]
[1,]    2   10
[2,]    4    8```

If any of the column numbers is out of bounds for given matrix, then R throws Error “subscript out of bounds”.

Let us try to get a columns at `columns = c(1, 2, 5)`, where the matrix has only `4` rows. Since column number `5` is out of bounds for the given matrix, R must throw the error.

example.R

```data <- c(2, 4, 7, 5, 10, 8, 1, 3)
A <- matrix(data, nrow = 2)
columns <- A[, c(1, 2, 5)]```

Output

`Error in A[, c(1, 2, 5)] : subscript out of bounds`

### Conclusion

In this R Tutorial, we learned how to get multiple columns of a Matrix at given column positions in R, with the help of examples.