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?

The amount of passengers dead are higher than the number that survived.

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

The largest group that did not survive was class 3 males. There was a total of 441 deaths in class 3.

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

The largest group that survived was in 1st class females. A total of 134 first class females survived.

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 would be within the 3rd class males. More cases of males that 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 would be the 3rd class males.

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.

1- More patients did not improve.

2- The largest group was placebos that did not improve.

3- The largest group that did not improve was the treated patients that showed marked improvement.

4- Patients that had marked improvement with treatment had more cases than expected.

5- Marked improvement form placebos had less causes than expected.

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.

Q9 Display the title and your name correctly at the top of the webpage.

Q10 Use the correct slug.