Exercise

# What's a matrix?

In R, a matrix is a collection of elements of the same data type (numeric, character, or logical) arranged into a fixed number of rows and columns. Since you are only working with rows and columns, a matrix is called two-dimensional.

You can construct a matrix in R with the `matrix()`

function. Consider the following example:

```
matrix(1:9, byrow = TRUE, nrow = 3)
```

In the `matrix()`

function:

- The first argument is the collection of elements that R will arrange into the rows and columns of the matrix. Here, we use
`1:9`

which is a shortcut for`c(1, 2, 3, 4, 5, 6, 7, 8, 9)`

. - The argument
`byrow`

indicates that the matrix is filled by the rows. If we want the matrix to be filled by the columns, we just place`byrow = FALSE`

. - The third argument
`nrow`

indicates that the matrix should have three rows.

Instructions

**100 XP**

Construct a matrix with 3 rows containing the numbers 1 up to 9, filled row-wise.