Basic Functions

Question 1

What function should I call to round up a number? What package do I need to load?

Answer 1

ceiling( )

No package needs to be loaded since this function is from base package.

Question 2

How can I check the version of a package?

Answer 2

By calling function:

packageVersion(“tidyverse”)

Question 3

How can I find the file path of a specific R package in my system?

Answer 3

system.file(package = “tidyverse”)

Question 4

What function do I call to see a brief description of a package? How does the function do that?

Answer 4

packageDescription(“tidyverse”)

It parses the DESCRIPTION file of the package and returns it as an object of class “packageDescription”.

Question 5

How can I search for all the available functions that start with “read” ?

Answer 5

apropos(“^read”)

Question 6

How can I get the list of functions/objects within a specific package? What’s the type and class of the returned object?

Answer 6

ls(“package:readr”)

It returns a character vector with them names of the functions. Class and type are character.

Question 7

How can I get the list of functions/objects within a specific package starting with a specific word?

Answer 7

ls(“package:readr”) %>%

str_subset(“^read_”)

Question 8

What is a vignette and how do I use one?

Answer 8

Vignettes are optional suplemental documentation provided by packages that look more like Tutorials.

I can access a vignette of a package using function vignette provided by utils:

vignette(“readr”)

Question 9

Qual função eu uso para declarar polinômios?

Answer 9

poly