1. Start RStudio. Go to the console and calculate the following
2. Create a new R Markdown file titled “Lab Week 2 [LASTNAME]”, and
at the beginning of the file, type the following message
3. Create a chunk and calculate the following in one chunk:
sqrt(16)
## [1] 4
16^0.5
## [1] 4
43
## [1] 43
4. In the console, type ?log. See what happens to the help window on
the lower right side.
5. In the R Markdown file, create a second chunk that contains the
following syntax
pi
## [1] 3.141593
round(pi)
## [1] 3
round(pi, digits=4)
## [1] 3.1416
trunc(pi)
## [1] 3
6. In the R Markdown file, create a vector x that contains (3, 6,
8)…
# create x
x <- c(3, 6, 8)
# see the output of x
print(x)
## [1] 3 6 8
# calculate x/2
x/2
## [1] 1.5 3.0 4.0
#calculate x^2
x^2
## [1] 9 36 64
#calculate sqrt(x)
sqrt(x)
## [1] 1.732051 2.449490 2.828427
#find the second element of x
x[2] #The second element of x is 6
## [1] 6
#find the first and third element of vector x
x[1] # The first element of x is 3
## [1] 3
x[3] # The third element of x is 8
## [1] 8
#generate a vector y that contains values of (2, 5, 1)
y <- c(2, 5, 1)
#print y
print(y)
## [1] 2 5 1
#calculate x-y
x-y
## [1] 1 1 7
#calculate x*y
x*y
## [1] 6 30 8
7. Assume that we have registered the height and weight for four
people: Heights in cm are 180, 165, 160, 193; weights in kg are 87, 58,
65, 100. Make two vectors, height and weight, with the data. The body
mass index (BMI) is defined as: weight in kg /(height in m)2. Make a
vector with the BMI values for the four people.
#Heights in cm are 180, 165, 160, 19
#weights in kg are 87, 58, 65, 100
#Make two (vectors, height and weight, with the data
height<- c(180, 165, 160, 19)
weight<- c(87, 58, 65, 100)
#Convert height to meters since the formular wants height in meters
new_height<- height/100
new_height
## [1] 1.80 1.65 1.60 0.19
#BMI values for the four people
BMI <- weight/(new_height^2)
BMI
## [1] 26.85185 21.30395 25.39062 2770.08310
8. Make a vector called score, which contains the following
statistics 77, 93, 92, 68,75,100…
#create score
score <- c(77, 93, 92, 68,75,100)
#this calculates the summary of all scores
sum(score)
## [1] 505
#sorting
sort (score)
## [1] 68 75 77 92 93 100
#median
median(score)
## [1] 84.5
#standard deviation
sd(score)
## [1] 12.54459
#variance
var(score)
## [1] 157.3667
#minimum value
min(score)
## [1] 68
#maximum value
max(score)
## [1] 100
9. Load a library called MASS, and load the data within the MASS
library called cats…
#load library
library(MASS)
#read data
data(cats)
#What’s the dimension of the data “cats”?
dim(cats) # 144 by 3
## [1] 144 3
#How many variables are there?
ncol(cats) # 3
## [1] 3
#What are they?
colnames(cats) # "Sex" "Bwt" "Hwt"
## [1] "Sex" "Bwt" "Hwt"
#How many observations are there?
nrow(cats) # 144
## [1] 144
#Is sex a factor variable?
is.factor(cats$sex) # False
## [1] FALSE
10. Load a dataset called “Week_2_Data.dta”…
#Load library
library(haven)
#read data
data<-read_dta('~/Documents/others/Week_2_Data.dta')
#Check if the data set has been imported correctly.
head(data)
#What’s the dimension of the data “cats”?
dim(data) # 131361 by 5
## [1] 131361 5
#How many variables are there?
ncol(data) # 5
## [1] 5
#How many observations are there?
nrow(data) # 131361
## [1] 131361
#What’s the average education (in years) among all respondents?
mean(data$educ, na.rm = TRUE)
## [1] 13.03642
11. a. Enter the following into a vector with the name color.
Remember to surround each piece of text with quotes.
color <- c("purple", "red", "yellow", "brown")
color
## [1] "purple" "red" "yellow" "brown"
# b. Display the 2nd element in the vector (red) in the console.
color[2]
## [1] "red"
#c. Enter the following into a vector with the name weight:
weight <- c(23, 21, 18, 26)
weight
## [1] 23 21 18 26
# d. Join the 2 vectors together using the data.frame function to make a data frame named info with 2 columns and 4 rows.
info <- data.frame(color,weight)
# e. Display the data frame in the console.
info
12. Save your work and submit your R markdown file (.html) through
Canvas (Assignments – Week 2 Lab).