One of R`s cool features is functional programming. It makes development much easier and the code you write shorter and less prone to errors. There are a few tool kits for functional programming in R (with famous base`s apply functions family among them). In this set of exercises,you will familiarize yourself with basic functions from the purrr package, which has a great advantage of being consistent both internally and with the rest of the tidyverse packages.
Answers to the exercises are available here.
Please, do all exercises using the purrr package. If you obtained a different (correct) answer than those listed on the solutions page, please feel free to post your answer as a comment on that page.
Exercise 1
Calculate the factorial for numbers from 1 to 10.
Exercise 2
Create a data.frame with cross products of letters from a to z (first column) and numbers from 1 to 10 (second column).
Exercise 3
For list list1 = list('a', data.frame(1:10), TRUE, 1, letters, 153) find the position of the first element of the list that is numeric.
Exercise 4
For list1, check if every element is of an atomic type.
Exercise 5
Select only atomic elements of list1.
Exercise 6
Check if the letter ‘b’ is an element of list1.
Exercise 7
Calculate log for each element of list1 and handle errors.
Exercise 8
Run each function from the list list2 = list(rnorm, runif, rcauchy) to generate 10 samples.
Exercise 9
Generate 5 series of 10 samples each from uniform distribution (0,1).
Exercise 10
Combine the list of series from exercise 9 into a single vector.
i don’t know how to do that,who can support an answer.
There’s an error with the link to solutions page.
Right one is
https://www.r-exercises.com/2018/01/19/functional-programming-with-purrr-solutions-part-2/
(19 instead of 13)