Question

What are the results when executing the provided code?

x <- c(1, 2, NA, 4, NA, 5)
bad <- is.na(x)
x[!bad]

Answer 1

When the provided R code is executed, it filters out the NA (missing) values from the vector x, resulting in a new vector containing only the non-missing values: 1, 2, 4, and 5.

Step-by-step explanation:

The question relates to a piece of code written in the R programming language, which is often used for statistical computing and graphics. When you execute the provided code:

x <- c(1, 2, NA, 4, NA, 5)
bad <- is.na(x)
x[!bad]

it performs the following actions:

1. Creates a vector x with numeric elements, including NA for missing values.
2. Uses the is.na() function to check each element of the vector x for missing values (NA), returning a logical vector bad of the same length.
3. Selects and displays all elements in the vector x that are not missing values using the '!' operator to negate the bad logical vector.

The result of executing this code is a numeric vector containing all the elements of the original vector x that were not NA, which are 1, 2, 4, and 5:

[1] 1 2 4 5

Thus, the code effectively filters out all the NA values from the original vector.