Lab 1



Labs Assignments

The purpose of this lab is to get you working with base R looping functions while also being careful about data types. Your are welcome to work with a partner or in a small group of 3-4 people.

Data structures

set.seed(123) # Set random number generation

m <- lm(mpg ~ hp + cyl + drat, mtcars)

l <- list(a = list(m = matrix(1:12, ncol = 3),
              	   v = 1:7),
          b = data.frame(student = 1:15,
                         score = rnorm(15, 100, 10)))

Run the above code

  1. From the model results:

    • Extract the qr tolerance (tol).
    • Extract the term labels from the model.
      • hint: Use str to inspect the list. This one is tricky and involves pulling an attribute from an attribute.

  2. From l

    • Use at least two different methods to extract m.
    • Extract the third column of m. Maintain the dimensions (matrix structure).
    • Extract the score for student 7 in the data frame.

Loops

  1. Read in the insurance_coverage.csv file, which is in the data folder in the repo. Split the data file by "age_bucket" and "sex_name".

  2. Use a for loop to calculate the mean health care population (hc_pop) for each "age_bucket"/"sex_name" combination.

  3. Replicate this calculation with lapply, sapply, and vapply

  4. Produce separate plots showing the change in hc_pop from 2014 to 2015 for each "age_bucket"/"sex_name" combination (with a single loop). Set the hc_pop axis so the limits equal the overall minimum and maximum values for hc_pop.

  5. Use a for loop to save the plots to a folder on your computer