2.1 Object Assignment

  1. Write R code to assign the value 20 to the name num_1.
  1. Which of the following is a valid object name in R?
  • 2.True
  • else
  • I_am_not_a_valid_name
  • I_am_a_Pretty#_name
  1. Write R code to get the list of all objects in the environment.

2.2 Numeric Vector, Character Vector, & Logical Vector

  1. Write R code to create a numeric vector named vec_1 with values (7, 24, 8, 26), get its length, and find out its type.
  1. Write R code to create a character vector named char_1 with values (“I”, “am”, “learning”, “R!”), get its length, find out its type, and concatenate the vector into a single string with space as the separator.
  1. For the char_1 defined in Q2, find the number of characters in each string, and convert each string to upper case.
  1. Create a length-2 logical vector representing whether vec_1 and char_1 are of character type.
  1. Let class1 <- c(7, TRUE). Which of the following is the class of class1?
  • numeric
  • logical
  • character
  1. Let class2 <- c(7, TRUE, "char"). Which of the following is the class of class2?
  • numeric
  • logical
  • character

2.3 Create Vectors with Patterns

  1. Write R code to create consecutive integers from -10 to 10.
  1. Write R code to create a decreasing sequence from 5 to 1 with increment -0.5.
  1. Write R code to create an equally-spaced sequence from 2 to 6 with length 10.
  1. Write R code using rep() function to create the string

c("sheep","pig", "cat","sheep","pig", "cat","sheep","pig", "cat")

  1. Write R code using rep() function to create the string

c("sheep","sheep","pig","pig","pig","pig","cat","cat","cat")