Editing R (programming language) (section)

=== Basic syntax ===
The following examples illustrate the basic [[programming language syntax|syntax of the language]] and use of the command-line interface.{{efn|An expanded list of standard language features can be found in the R manual, "An Introduction to R" {{URL|cran.r-project.org/doc/manuals/R-intro.pdf}}}}

In R, the generally preferred [[Assignment (computer science)|assignment operator]] is an arrow made from two characters <code><-</code>, although <code>=</code> can be used in some cases.<ref>{{cite web|author=R Development Core Team|title=Assignments with the = Operator|url=https://developer.r-project.org/equalAssign.html|access-date=2018-09-11}}</ref>

<syntaxhighlight lang="rout">
> x <- 1:6 # Create a numeric vector in the current environment
> y <- x^2 # Create vector based on the values in x.
> print(y) # Print the vector’s contents.
[1]  1  4  9 16 25 36

> z <- x + y # Create a new vector that is the sum of x and y
> z # Return the contents of z to the current environment.
[1]  2  6 12 20 30 42

> z_matrix <- matrix(z, nrow = 3) # Create a new matrix that turns the vector z into a 3x2 matrix object
> z_matrix 
     [,1] [,2]
[1,]    2   20
[2,]    6   30
[3,]   12   42

> 2 * t(z_matrix) - 2 # Transpose the matrix, multiply every element by 2, subtract 2 from each element in the matrix, and return the results to the terminal.
     [,1] [,2] [,3]
[1,]    2   10   22
[2,]   38   58   82

> new_df <- data.frame(t(z_matrix), row.names = c("A", "B")) # Create a new data.frame object that contains the data from a transposed z_matrix, with row names 'A' and 'B'
> names(new_df) <- c("X", "Y", "Z") # Set the column names of new_df as X, Y, and Z.
> print(new_df)  # Print the current results.
   X  Y  Z
A  2  6 12
B 20 30 42

> new_df$Z # Output the Z column
[1] 12 42

> new_df$Z == new_df['Z'] && new_df[3] == new_df$Z # The data.frame column Z can be accessed using $Z, ['Z'], or [3] syntax and the values are the same. 
[1] TRUE

> attributes(new_df) # Print attributes information about the new_df object
$names
[1] "X" "Y" "Z"

$row.names
[1] "A" "B"

$class
[1] "data.frame"

> attributes(new_df)$row.names <- c("one", "two") # Access and then change the row.names attribute; can also be done using rownames()
> new_df
     X  Y  Z
one  2  6 12
two 20 30 42

</syntaxhighlight>