On a half-sheet of paper,

• Write your name on the front and answer
  • What are the differences between a histogram and a boxplot?
  • What is the difference between a histogram and a barplot?

• On the back of this sheet, answer the following questions:

  1. What is the definition of "observational unit"?
  2. What are the three properties of a tidy data set?
  3. What are the Five Named Graphs we explored in this chapter?

Run the following first in your console to create the data example:

# Load packages
library(dplyr)
library(ggplot2)

# Create data frame
simple_ex <- data_frame(
    A = c(1, 2, 3, 4),
    B = c(1, 2, 3, 4),
    C = c(3, 2, 1, 2),
    D = c("a", "a", "b", "b")
  )

Let's view the data frame, which is in tidy format:

View(simple_ex)

• A statistical graphic is a mapping of data variables to aes()thetic attributes of geom_etric objects.
• A scatterplot has points as the geom_etric object
• A linegraph has lines as the geom_etric object

• the geom_etric objects are points
• the aesthetic attributes are:
  • x-axis is variable A
  • y-axis is variable B

ggplot(data = simple_ex, mapping = aes(x = A, y = B)) + 
  geom_point()

ggplot(data = simple_ex, mapping = aes(x = A, y = B)) + 
  geom_point()

• the geom_etric objects are points
• the aesthetic attributes are:
  • x-axis is variable A
  • y-axis is variable B
  • color is variable D

ggplot(data = simple_ex, mapping = aes(x = A, y = B, color = D)) + 
  geom_point()

ggplot(data = simple_ex, mapping = aes(x = A, y = B, color = D)) + 
  geom_point()

• the geom_etric objects are points
• the aesthetic attributes are:
  • x-axis is variable A
  • y-axis is variable B
  • size is variable C

ggplot(data = simple_ex, mapping = aes(x = A, y = B, size = C)) + 
  geom_point()

ggplot(data = simple_ex, mapping = aes(x = A, y = B, size = C)) + 
  geom_point()

• the geom_etric objects are lines
• the aesthetic attributes are:
  • x-axis is variable A
  • y-axis is variable B

ggplot(data = simple_ex, mapping = aes(x = A, y = B)) + 
  geom_line()

ggplot(data = simple_ex, mapping = aes(x = A, y = B)) + 
  geom_line()

• the geom_etric objects are lines
• the aesthetic attributes are:
  • x-axis is variable A
  • y-axis is variable B
  • color is variable D

ggplot(data = simple_ex, mapping = aes(x = A, y = B, color = D)) + 
  geom_line()

ggplot(data = simple_ex, mapping = aes(x = A, y = B, color = D)) + 
  geom_line()

• Complete PS8 by 10 AM on Monday, October 3
• Try the practice problems for the quiz here
• No lab due on Tuesday next week

• Quiz #2 individually
• Quiz #2 in groups of 3 (of your choosing)
• Go over Quiz #2