In this lab you can use the interactive console to explore or Knit the document. Remember anything you type here can be “sent” to the console with Cmd-Enter (OS-X) or Ctrl-Enter (Windows/Linux) in an R code chunk.
Create a new object called my.num that contains 6
numbers.
# General format
my.num <- c(number1, number2, ...)my.num <- c(5, 4, 7, 8, 12, 14) # These can be any real numbersMultiply my.num by 4.
my.num * 4## [1] 20 16 28 32 48 56Create a second object called my.char that contains 5
character strings.
# General format
my.char <- c("character1", "character2", ...)my.char <- c("banana", "garlic", "pickles", "hot chocolate", "7-Up") # Again,these can be anythingCombine the two objects my.num and my.char
into an object called both.
both <- c(my.num, my.char)What is the length of both? Use the
length() function.
length(both)## [1] 11What class is both?
class(both)## [1] "character"Create a vector that contains 4 sets of the numbers 1, 2, 3, and 4.
vec_1 <- c(1, 2, 3, 4)
vec_2 <- c(vec_1, vec_1, vec_1, vec_1)Divide both by 3, what happens?
both / 3## Error in both/3: non-numeric argument to binary operatorCreate a vector with elements 1, 2, 3, 4, 5 and call it
x.
# General format
x <- c(...)x <- c(1, 2, 3, 4, 5)Create another vector with elements 10, 20, 30, 40, 50 and call it
y.
# General format
y <- c(...)y <- c(10, 20, 30, 40, 50)Determine the length of x and y. Next, add
the vectors x and y together.
length(x)## [1] 5length(y)## [1] 5x + y## [1] 11 22 33 44 55# [1] 11 22 33 44 55Append the value 60 onto the vector y (hint: you can use
the c() function).
# General format
y <- c(y, ...)y <- c(y, 60)Determine the length of x and y.
length(x)## [1] 5length(y)## [1] 6Add x and y together. What happens?
x + y## Warning in x + y: longer object length is not a multiple of shorter object
## length## [1] 11 22 33 44 55 61# [1] 11 22 33 44 55 61
# Warning message:
# In x + y : longer object length is not a multiple of shorter object length
# R "auto replicates" the shorter vector when the vectors aren't the same length - this is not what we want!
# In this case, it reads x as c(1, 2, 3, 4, 5, 1)!Multiply the following a and b together.
How is this similar to the way R performs addition in #10 ?
a <- c(1, 2, 3)
b <- c(10, 100, 1000)a * b## [1] 10 200 3000# R adds together the first element of each vector, then the second, and so on. This order also applies when multiplying!Create a vector object called int_vect that starts at 1
and goes up to 10. Use seq().
# General format
seq(from = NUMBER, to = NUMBER)int_vect <- seq(from = 1, to = 10)
int_vect## [1] 1 2 3 4 5 6 7 8 9 10Repeat the int_vect object this sequence 3 times using
rep() and store the new object as
int_vect_3.
# General format - times and each are optional
rep(x = OBJECT_TO_REPEAT, times = NUM_TIMES_TO_REPEAT, each = NUM_TIMES_TO_REPEAT_EACH_ELEMENT)int_vect_3 <- rep(int_vect, times = 3)
int_vect_3## [1] 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5
## [26] 6 7 8 9 10What is the length of int_vect_3?
length(int_vect_3)## [1] 30Create a vector that takes the sequence “Strongly Agree”, “Agree”, “Neutral”, “Disagree”, “Strongly Disagree” and repeats each element 10 times.
my_seq <- c("Strongly Agree", "Agree", "Neutral", "Disagree", "Strongly Disagree")
rep(my_seq, each = 10)## [1] "Strongly Agree" "Strongly Agree" "Strongly Agree"
## [4] "Strongly Agree" "Strongly Agree" "Strongly Agree"
## [7] "Strongly Agree" "Strongly Agree" "Strongly Agree"
## [10] "Strongly Agree" "Agree" "Agree"
## [13] "Agree" "Agree" "Agree"
## [16] "Agree" "Agree" "Agree"
## [19] "Agree" "Agree" "Neutral"
## [22] "Neutral" "Neutral" "Neutral"
## [25] "Neutral" "Neutral" "Neutral"
## [28] "Neutral" "Neutral" "Neutral"
## [31] "Disagree" "Disagree" "Disagree"
## [34] "Disagree" "Disagree" "Disagree"
## [37] "Disagree" "Disagree" "Disagree"
## [40] "Disagree" "Strongly Disagree" "Strongly Disagree"
## [43] "Strongly Disagree" "Strongly Disagree" "Strongly Disagree"
## [46] "Strongly Disagree" "Strongly Disagree" "Strongly Disagree"
## [49] "Strongly Disagree" "Strongly Disagree"rep(c("Strongly Agree", "Agree", "Neutral", "Disagree", "Strongly Disagree"), each = 10)## [1] "Strongly Agree" "Strongly Agree" "Strongly Agree"
## [4] "Strongly Agree" "Strongly Agree" "Strongly Agree"
## [7] "Strongly Agree" "Strongly Agree" "Strongly Agree"
## [10] "Strongly Agree" "Agree" "Agree"
## [13] "Agree" "Agree" "Agree"
## [16] "Agree" "Agree" "Agree"
## [19] "Agree" "Agree" "Neutral"
## [22] "Neutral" "Neutral" "Neutral"
## [25] "Neutral" "Neutral" "Neutral"
## [28] "Neutral" "Neutral" "Neutral"
## [31] "Disagree" "Disagree" "Disagree"
## [34] "Disagree" "Disagree" "Disagree"
## [37] "Disagree" "Disagree" "Disagree"
## [40] "Disagree" "Strongly Disagree" "Strongly Disagree"
## [43] "Strongly Disagree" "Strongly Disagree" "Strongly Disagree"
## [46] "Strongly Disagree" "Strongly Disagree" "Strongly Disagree"
## [49] "Strongly Disagree" "Strongly Disagree"“Strongly Agree”, “Agree”, “Neutral”, “Disagree”, “Strongly Disagree”
are often responses to surveys. Create a randomly sampled vector of 30
survey responses. (hint use sample() and set the replace
argument to TRUE). Store the output as
my_responses. Examine the data by typing the name
my_responses in the Console.
my_responses <- sample(
x = c("Strongly Agree", "Agree", "Neutral", "Disagree", "Strongly Disagree"),
size = 30,
replace = TRUE
)
my_responses## [1] "Disagree" "Strongly Agree" "Strongly Agree"
## [4] "Disagree" "Disagree" "Strongly Agree"
## [7] "Neutral" "Strongly Agree" "Strongly Agree"
## [10] "Strongly Agree" "Strongly Disagree" "Neutral"
## [13] "Disagree" "Strongly Disagree" "Agree"
## [16] "Strongly Agree" "Strongly Agree" "Neutral"
## [19] "Agree" "Strongly Disagree" "Agree"
## [22] "Strongly Agree" "Strongly Disagree" "Strongly Agree"
## [25] "Strongly Disagree" "Disagree" "Strongly Disagree"
## [28] "Disagree" "Neutral" "Disagree"Let’s say you change your survey so participants can rank their
response 1-10 (inclusive). Create a randomly sampled vector of 30 survey
responses. (hint use seq() and sample() and
set the replace argument to TRUE). Store the output as
my_responses_2. Examine the data by typing the name
my_responses_2 in the Console.
my_responses_2 <- sample(
x = seq(from = 1, to = 10),
size = 30,
replace = TRUE
)