Mosaic Plot

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?

Q2 Describe the largest group that didn’t survive. Discuss by class and gender.

The largest group that didn’t survive were males in 3rd class

Q3 Describe the largest group that did survive. Discuss by class and gender.

The largest group that did survive were females in 1st class

Q4 Describe one group that has more cases than expected given independence (by chance). Discuss by class and gender.

One group that has more cases than expected given independence were 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.

One group that has less cases than expected given independence were 3rd class males who survived.

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?

Q2 Describe the largest group that didn’t improve. Discuss by treatment.

The largest group that didn’t improve were patients who recieved the placebo

Q3 Describe the largest group that did improve. Discuss by treatment.

The largest group that improved were patients who recieved treatment

Q4 Describe one group that has more cases than expected given independence (by chance). Discuss by treatment.

The group with more cases than expected given independence were patients who recieved treatment

Q5 Describe one group that has less cases than expected given independence (by chance). Discuss by treatment.

The gorup with less cases than expected given independence were patients who improved and recieved 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.