Vectorized code: multiplication
The following piece of code is written like traditional C or Fortran code. Instead of using the vectorized version of multiplication, it uses a for loop.
x <- rnorm(10)
x2 <- numeric(length(x))
for(i in 1:10)
x2[i] <- x[i] * x[i]
Your job is to make this code more "R-like" by vectorizing it. x is available for you to use.
This exercise is part of the course
Writing Efficient R Code
Exercise instructions
- Read the example code above, and try to understand what it is calculating.
- Rewrite that code using a vectorized solution. Hints:
- Your solution should be a single line of code.
- You should not use a
forloop. - The multiplication operator is vectorized!
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Store your answer as x2_imp
x2_imp <-