hw04 ready for grading

[nbendriem]

Hey Dana,

Your homework assignment looks great! You completed both activities with tables and a consequent graph to illustrate the results.

Activity 1:

Your two graphs of Life Expectancy and Soy harvests for Brazil are wonderful. Very easy to read. I also liked that you explain each step as you go through it, especially since this was a “choose your own activity” type of homework and not everyone had to do the same steps you did.

Activity 2:

Very well done using the spread function to move Brazil and Canada from rows to columns. Your graph also looks great and is easy to follow, and you explained your steps very effectively.

Comments:

It would be helpful to make individual folders for each homework assignment. The links are wonderful and can direct the reviewer to the right document but it would make your homework folder less cluttered and more organized.

You mentioned you tried to use the knitr::kable() function for your table of Canada and Brazil using the spread function as well. Have you tried simply using kable()? That seems to work for me when im using R Studio. I switch to kable(format=”html”) when I am done on R studio and ready to knit an html file and it seems to work well when looking at the .md file.

You can add a title to your graphs and tables (purely aesthetic) using ggtitle or in the kable function, you can add caption=”TITLE”

Did you create the new dataframe using R or excel? I ended up using Excel and saving it as a csv file to upload it to R but I am curious as to how easy it is to use R Studio, in case that's the method you chose.

Did you use any resources outside of the class notes? There is a great cheatsheet that I found very helpful especially when dealing with the different join options

Cheers!

Nathan

[dorawyy]

Hi Dana,

Glad to review your assignment4. Overall I think you did good work:

• I do appreciate the Reflections on HW 4 part you have in the repo README file. It helps me get a full picture of how you feel about the assignment.
• I like your coding style. It is neat and easy to follow with helpful and appropriate comments (both in code and in text format).

For Activity1 of General data reshaping and relationship to aggregation:

• When preparing data to use, you applied select() and filter() to reformat and filter data frame;
• You used spread in the correct way;
• You used geom_line() and created a good-looking and neat line figure;
• I didn't know theme_bw() before, and I looked the function up when reviewing your assignment. I feel it really easy and neat to use for setting the theme of ggplot2. 👍 I will also use it in my following assignment. 😄

For Activity2 of Join, merge, look up part:

• As I read your README file first, thus I had a better understanding about what data you chose/ why you chose that in the activity, which is really helpful. :)
• You applied domain type conversion functions when preparing data for joining. For example, as.integer(), which is good and clear;
• You explored arguments available for join functions, for example, by parameter;
• You applied gather() function here, in a correct way.

Here are some friendly suggestions:

• In Activity1 of General data reshaping and relationship to aggregation, the assignment says

  Take advantage of this new data shape to scatterplot life expectancy for one country against that of another.

I do feel it is reasonable to use eom_line() , however, it could be better if you also include the scatterplot to satisfy the assignment requirement;

• In Activity2 of Join, merge, look up part, what you did is good! It could be better if you explored different types of join, then compare the returned data frame to see the difference of different types of join.

• Not sure what kind of problem you met about knitr::kable, but I also met some problems with it too. Everything worked well in my R markdown but when I uploaded the markdown file produced from .Rmd file to Github, everything is totally messed up. The solution to my issue is to add a the paramter format = 'markdown' here:

  knitr::kable(table, align = 'c', format = 'markdown', digits = 2)

  (credit to Joey -- posted in slack) Hope this helps! 😃

-Yingying

[derekcho]

Hi @danaj191, here are some comments about your hw04:

• For your first task, nice work converting your data to wide form using spread. However, I noticed that you named your wide form table “df_BRCA_long” when in fact the original data is in long form. The plot that you show is more easily done using long form data rather than wide form.
• It isn’t really clear why you have to use read.csv() on df_BRcensus after manually inputting it like you did. You should either read the data from a file and then show it, or just input it as a matrix.
• It is hard to follow with what you are trying to do in this part. Although you provide good comments in your code, it is important to actually show an example of the table(s) before and after joining them. In addition, you should try to explore different types of joins rather than just an inner join.

Your grade will be emailed to you at a later date.