R quick quiz Find out whether you need a really, really basic R course or if you're okay to do some data processing already. jicawi published on April 21, 2016 Stacked 1/20 Which of the following does NOT call a function? > ?help > ??help > help > help() 2/20 read.delim() gives you what? vector data.frame factor character 3/20 You're not sure if a function "furbies" is available... which of the following would tell you for sure? > ?furbies > exists("furbies") > furbies [all of these] 4/20 What is R? R is a free software environment for statistical computing and graphics R is a family of operating systems for x86-based computers R is an esoteric programming language created in 1993 by Urban Müller, and notable for its extreme minimalism R is an integrated family of products that helps to address the entire analytical process, from planning and data collection to analysis, reporting and deplo... 5/20 By default, what will happen when a column containing mostly numbers but some text is read by read.table() ? The text will get replaced by zeroes The text will get replaced by NA() The column will be a factor The column is illegal and will be removed 6/20 Which of the following do you use to load a package in R? > install.packages() > load() > library() > source() 7/20 Which of the following is NOT an R data type? logical complex raw factor 8/20 Which of the following would you use to read a table in a file called "table.csv"? > read.table.csv() > read.csv("table.csv") > "table.csv" > table.csv() 9/20 A true/false value in R is held in which data-type? logical illogical binary raw 10/20 How many data types are there in R? 1 3 6 9 11/20 If you wanted to install R, where would you download it from? r-project.org cpan.org rstudio.com cran.org 12/20 > df = data.frame(a=c(1,2,3),b=c(4,5,6))Which two commands give you the number 4? Hint: 2 choices > df[1,2] > df$b[1] > df[2,1] > df[2:1] > df[1:2] 13/20 The following code creates what? > c(a=c(1,2),b=c(3,4)) A data.frame with 2 rows and 2 columns A numeric vector with named values A factor vector A list 14/20 What does this mean?1:10 A numeric vector containing the numbers 1 to 10 A numeric vector containing the numbers 1 and 10 An integer vector containing the numbers 1 to 10 An integer vector containing the numbers 1 and 10 15/20 Which of the following does not contain numbers? numeric integer raw character 16/20 You're confused about data.frames. Which of the following does not help? > ?base > ?data.frame > library(help="data.frame") > library(help="base") 17/20 What is a data.frame? A data structure with the same number of rows and columns A data structure with columns of equal length that can contain different data types from each other A data structure with columns of equal length that must all contain the same data type A vector of list objects 18/20 What is a matrix? A data structure with the same number of rows and columns A data structure with columns of equal length that can contain different data types from each other A data structure with columns of equal length that must all contain the same data type A vector of list objects 19/20 Which of the following is NOT an R data structure? factor array list character 20/20 Which of the following does NOT assign the value "foo" to the variable f? > f <- "foo" > "foo" -> f > f = "foo" > f <= "foo"