How to use sapply
You can use sapply() similar to how you used lapply(). The first argument of sapply() is the list or vector X over which you want to apply a function, FUN. Potential additional arguments to this function are specified afterwards (...):
sapply(X, FUN, ...)
In the next couple of exercises, you'll be working with the variable temp, that contains temperature measurements for 7 days. temp is a list of length 7, where each element is a vector of length 5, representing 5 measurements on a given day. This variable has already been defined in the workspace: type str(temp) to see its structure.
This is a part of the course
“Intermediate R”
Exercise instructions
- Use
lapply()to calculate the minimum (built-in functionmin()) of the temperature measurements for every day. - Do the same thing but this time with
sapply(). See how the output differs. - Use
lapply()to compute the the maximum (max()) temperature for each day. - Again, use
sapply()to solve the same question and see howlapply()andsapply()differ.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# temp has already been defined in the workspace
# Use lapply() to find each day's minimum temperature
# Use sapply() to find each day's minimum temperature
# Use lapply() to find each day's maximum temperature
# Use sapply() to find each day's maximum temperatureThis exercise is part of the course
Intermediate R
Continue your journey to becoming an R ninja by learning about conditional statements, loops, and vector functions.
Whenever you're using a for loop, you may want to revise your code to see whether you can use the lapply function instead. Learn all about this intuitive way of applying a function over a list or a vector, and how to use its variants, sapply and vapply.
Exercise 1: lapplyExercise 2: Use lapply with a built-in R functionExercise 3: Use lapply with your own functionExercise 4: lapply and anonymous functionsExercise 5: Use lapply with additional argumentsExercise 6: Apply functions that return NULLExercise 7: sapplyExercise 8: How to use sapplyExercise 9: sapply with your own functionExercise 10: sapply with function returning vectorExercise 11: sapply can't simplify, now what?Exercise 12: sapply with functions that return NULLExercise 13: Reverse engineering sapplyExercise 14: vapplyExercise 15: Use vapplyExercise 16: Use vapply (2)Exercise 17: From sapply to vapplyWhat is DataCamp?
Learn the data skills you need online at your own pace—from non-coding essentials to data science and machine learning.