Mosaic Plot
Tom Albert
10/16/2019
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
Q2 Describe the largest group that didn’t survive. Discuss by class and gender.
males in 3rd class
Q3 Describe the largest group that did survive. Discuss by class and gender.
females in 1st class
Q4 Describe one group that has more cases than expected given independence (by chance). Discuss by class and gender.
3rd class males who did not survive
Q5 Describe one group that has less cases than expected given independence (by chance). Discuss by class and gender.
3rd class males who did survive
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.
Q1 Are more patients improved?
no more did not improve
Q2 Describe the largest group that didn’t improve. Discuss by treatment.
The largest group that didnt improve was the patients that recieved the placebo drug.
Q3 Describe the largest group that did improve. Discuss by treatment.
the largest group who improved were the ones who recieved the actual treatment.
Q4 Describe one group that has more cases than expected given independence (by chance). Discuss by class and gender.
patients who recieved treatment
Q5 Describe one group that has less cases than expected given independence (by chance). Discuss by class and gender.
patients who improved and took the placebo
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.