data science The land of data frames

Please write this up as using Rmarkdown. Make sure everything runs. Answer questions in text. Comment with abandon.

1. Create a vector of 100 randomly distributed numbers between 0 and 100 using runif and save the vector into the variable my_vec. What information does str and summary tell you about my_vec? How do they differ?
2. Load the readxl and readr libraries. They are part of tidyverse and you should have them. If not, install.packages() is your friend! Then, load the following data files: https://biol355.github.io/Data/my_data.csv using read.csv and read_csv and https://biol355.github.io/Data/my_data.xlsx using read_excel. Looking at the three objects you loaded in, what are the any differences or similarities between them?
3. What does the output of str, summary, skimr::skim(), and visdat::vis_dat tell you about the data you loaded? What is different or the same?
4. Add a column to the mtcars data called Model which uses the row names of mtcars (rownames(mtcars)) as its values. Show me the head of the data frame to see if it’s been done correctly. Note, to add a column to a data frame, we can specify yourdf$new_col_name <- new_vector_we_we_are_adding (note, that’s pseudo-code). Note how we are using the $ notation to add a new column.
5. Let’s use the bind_rows function in dplyr, as it’s pretty powerful. Let’s say you want to add a new row to mtcars for a new model. Make a new data frame with the following columns: Model = Fizzywig, mpg=31.415, awesomness=11. Now try to make a new data frame where you rbind mtcars and this new data frame. What happens? Don’t do this in a markdown code chunk – just try it, and then report what happens. It might or might not go as planned (and Rmarkdown can choke unless you add the appropriate argument to the code chunk – more on that soon)! Then, make a new data frame here you use dplyr::bind_rows to combine them. Examine the resulting data frame. What do you see? You can try this in a code chunk for your markdown. How do the two methods differ? Look at their help files for some information that might help you.