Mosaic Plot
Serena Govaert
10/8/2019
In this exercise you will learn to visualize the pairwise relationships between a set of quantitative variables. To this end, you will make your own note of 8.5 Mosaic plots from Data Visualization with R.
Mosaic charts can display the relationship between categorical variables using:
- rectangles whose areas represent the proportion of cases for any given combination of levels, and
- the color of the tiles to indicate the degree relationship among the variables.
The Titanic data set came from https://osf.io/aupb4/.
In the graph below,
- dark blue represents more cases than expected given independence (by chance); and
- dark red represents less cases than expected if independence holds (by chance).
Q1 Are more passengers survived?
no more people died
Q2 Describe the largest group that didn’t survive. Discuss by class and gender.
Third class male passengers
Q3 Describe the largest group that did survive. Discuss by class and gender.
first class female passengers
Q4 Describe one group that has more cases than expected given independence (by chance). Discuss by class and gender.
Third class male passengers that didn’t survive had more cases than expected
Q5 Describe one group that has less cases than expected given independence (by chance). Discuss by class and gender.
Third class males passengers that did survive had less cases than expected
Q6 Create a mosaic plot for Arthritis in the same way as above.
Hint: The Arthritis data set is from the vcd package. Add an additional argument gp = shading_max in the mosaic function. This is because the residuals are too small to have color.
Q7 Repeat Q1-Q5.
Q8 Hide the messages, the code and its results on the webpage.
Hint: Use message, echo and results in the chunk options. Refer to the RMarkdown Reference Guide.