Selection by comparison I
Sometimes you want to select elements from a vector in a more advanced fashion. This is where the use of logical operators may come in handy.
The (logical) comparison operators known to R are:
- < for less than
- > for greater than
- <= for less than or equal to
- >= for greater than or equal to
- == for equal to each other
- != not equal to each other
The nice thing about R is that you can use these comparison operators on vectors. For example, the statement c(4,5,6) > 5 returns: FALSE FALSE TRUE. In other words, you test for every element of the vector if the condition stated by the comparison operator is TRUE or FALSE.
Behind the scenes, R does an element-wise comparison of each element in the vector c(4,5,6) with the element 5. However, 5 is not a vector of length three. To solve this, R automatically replicates the value 5 to generate a vector of three elements, c(5, 5, 5) and then carries out the element-wise comparison.
This exercise is part of the course
Basic Statistics
Exercise instructions
- Check which values in
numeric_vectorare larger than 10. Assign the result to the variablelarger_than_ten. - print the variable
larger_than_tento the console.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# A numeric vector containing 3 elements
numeric_vector <- c(1, 10, 49)