Ex-2-2: Fine tuning figures

1 Exercise 1

Using the diamonds data,

  • Create a histogram for diamond prices (price).
    • Set bin fill color to a color you like using its Hex code
    • Set bin border color to a color you like using its Hex code
    • Set bins = 30
  • Change the panel background color to #6f6f6f using the panel.background option inside theme().
  • Increase the x-axis and y-axis label text size to 12
  • Change the y-axis breaks to seq(0, 15000, by = 1000)
  • Change the color and size of x-axis title to “blue” and 16, respectively
  • Change the color and size of y-axis title to “red” and 16, respectively
  • Remove the minor grid lines of the y-axis

Here is the output you should be getting:

Code 
ggplot(data = diamonds) +
  geom_histogram(
    aes(x = price),
    color = "#000000",
    fill = "#c90076",
    bins = 30
  ) +
  theme(
    axis.text = element_text(size = 12),
    axis.title.x = element_text(size = 16, color = "blue"),
    axis.title.y = element_text(size = 16, color = "red"),
    panel.grid.minor.y = element_blank(),
    panel.background = element_rect(fill = "#6f6f6f")
  ) +
  scale_y_continuous(breaks = seq(0, 15000, by = 1000))

2 Exercise 2

Using the iris data,

  • Generate a boxplot of sepal lengths (Sepal.Length) for each species (Species)
  • Apply one of the pre-made themes by the ggthemes package
  • Pick one palette from the list of “qualitative” palettes by the RColorBrewer package (You can see the list by running display.brewer.all(type = "qual").)
  • Use the palette you picked in scale_A_B() to change the color scheme from the default
    • A: fill or color
    • B: brewer or distiller
  • Place the legend title at the top of the legend keys
  • Change the y-axis title to “Sepal Length”
  • Change the breaks of the y-axis to seq(4, 8, by = 0.5)
  • Make the font size of x-axis text 12
  • Change the color x-axis title to a color you like using the Hex code
  • Place the legend at the bottom of the figure
  • Change the width of the legend keys to 1cm.
  • Remove the minor grid lines of the y-axis

Here is the output you should be getting:

Code 
ggplot(data = iris) +
  geom_boxplot(aes(x = Species, y = Sepal.Length, fill = Species)) +
  theme_bw() +
  scale_fill_brewer(
    palette = "Set2",
    guide = guide_legend(title.position = "top")
  ) +
  ylab("Sepal Length") +
  theme(
    panel.grid.minor.y = element_blank(),
    axis.text.x = element_text(size = 16),
    axis.title.x = element_text(color = "#cc0000"),
    legend.position = "bottom",
    legend.key.width = unit(1, "cm")
  ) +
  scale_y_continuous(breaks = seq(4, 8, by = 0.5))

3 Exercise 3

Using the mpg data,

  • Create a scatter plot of highway miles-per-gallon (hwy) against engine displacement (displ).
    • Modify the point color based on drive type (drv).
    • Set the size of the points to 3
  • Use scale_AviridisB() to apply the Viridis color scale
    • A: color or fill
    • B: c (continuous) or d (discrete)
  • Legend:
    • Rename the legend title to “Drive Type”.
    • Place the legend at the bottom of the figure
  • Axis
    • Change the y-axis and x-xis titles to “Miles per gallon” and “Displacement”, respectively
    • Change the font size of y-axis and x-axis titles to 16
    • Change the font size of y-axis and x-axis texts to 12
  • Others:
    • Make the background color of the panel to #f3fbf5 using the panel.background option inside theme().

Here is the output you should be getting:

Code 
ggplot(data = mpg) +
  geom_point(aes(x = displ, y = hwy, shape = drv, color = class), size = 3) +
  scale_shape_manual(
    name = "Drive Type",
    values = c("f" = 16, "r" = 17, "4" = 18),
    labels = c("Front", "Rear", "Four-wheel")
  )

4 Exercise 4

Using county_yield_y,

  • Create a line plot of corn yield (corn_yield) against year (year) faceted by State (state_name)
  • Apply theme_wsj()
  • Axis
    • Change the y-axis and x-axis titles to “Corn Yield (bu/acre)” and “Year”, respectively
    • Change the breaks of x-axis to 2000:2018
  • Theme
    • Change the font size of x-axis and y-axis titles to 16
    • Change the font size of x-axis and y-axis texts to 12
    • Change the background color of the strips to #fbf3f9
    • Change the background border color of the strips to blue
    • Change the strip text size to 12 and set its angle to 0

Here is the output you should be getting:

Code 
ggplot(data = county_yield_y) +
  geom_line(aes(x = year, y = corn_yield)) +
  facet_grid(state_name ~ .) +
  theme_wsj() +
  ylab("Corn Yield (bu/acre)") +
  xlab("Year") +
  scale_x_continuous(breaks = 2000:2018) +
  theme(
    axis.text = element_text(size = 12),
    axis.title = element_text(size = 16),
    strip.background = element_rect(fill = "#fbf3f9", color = "blue"),
    strip.text.y = element_text(size = 12, angle = 0)
  )