Exercise 3_2_3: Plotting Repeats

History Plotting repeats. Let’s dive into ggplot2 and repeat what we’ve done in base R using the “grammar of graphics”.

Here’s the Allbus 2021 data again.

library(dplyr)
library(haven)

allbus_2021_dvI <- 
  read_sav(
    "./data/allbus_2021ZA5280_v1-0-0.sav"
  ) %>% 
  sjlabelled::set_na(na = c(-1:-99, 97, 98))

1

Create a scatter plot for the variables pa01 (political_orientation) and fr03b (children suffer under working mothers).

Clues

Remember the order of layers: data + aesthetics + geoms

solution

library(ggplot2)

ggplot(
  allbus_2021_dvI,
  aes(pa01, fr03b)
) +
  geom_point()

## Don't know how to automatically pick scale for object of type haven_labelled/vctrs_vctr/double. Defaulting to continuous.
## Don't know how to automatically pick scale for object of type haven_labelled/vctrs_vctr/double. Defaulting to continuous.

## Warning: Removed 1951 rows containing missing values (geom_point).

2

Add some jitter to the scatter plot.

Clues

In contrast to the base R function jitter does not have to be added; it just replaces the original geom using geom_jitter()

solution

ggplot(
  allbus_2021_dvI,
  aes(pa01, fr03b)
) +
  geom_jitter()

## Don't know how to automatically pick scale for object of type haven_labelled/vctrs_vctr/double. Defaulting to continuous.
## Don't know how to automatically pick scale for object of type haven_labelled/vctrs_vctr/double. Defaulting to continuous.

## Warning: Removed 1951 rows containing missing values (geom_point).

3

Boxplots are boring, right? Try to plot the relationship between pa01 (political_orientation) and fr03b (children suffer under working mothers) as a violin plot! Have a look here for reference: https://ggplot2.tidyverse.org/reference/

What’s the difference to a boxplot?

Clues

You can’t find the proper geom? Try geom_violin().

solution

ggplot(
 allbus_2021_dvI,
  aes(pa01, fr03b)
) +
  geom_violin()

## Don't know how to automatically pick scale for object of type haven_labelled/vctrs_vctr/double. Defaulting to continuous.
## Don't know how to automatically pick scale for object of type haven_labelled/vctrs_vctr/double. Defaulting to continuous.

## Warning: Removed 1951 rows containing non-finite values (stat_ydensity).

# In contrast to simple boxplots, violin plots show densities and can, e.g.,
# help to assess whether a variable is normally distributed or not.