HW1

  • Due Sep 18, 2020 by 11:59pm
  • Points 100
  • Submitting a file upload

Homework Project 1

Problem 1.1 (Long-to-Wide Data format translation):

We demonstrated the wide-to-long conversion in lecture. Now, let’s explore long-to-wide. Load in the long-format SOCR Parkinson's Disease data. and export it as wide format. For simplicity, just choose only 3 variables (avoiding case and time variables). Please note that there are several time observations for each subject. You need to transform the features according to the time variable. Try to use reshape function.

Problem 1.2 (Data stratification):

Use the same SOCR Parkinson's Disease data. and extract rows satisfying Time=0. Complete the following protocol in R:

  • Extract the first 10 subjects
  • Find the cases for which L_caudate_ComputeArea<600.
  • Sort the subjects based on L_caudate_Volume in descending and ascending order.
  • Generate frequency and probability tables for Age and Sex.
  • Compute the mean Age and the correlation between Age and Weight.
  • Plot Histogram and density of R_fusiform_gyrus_Volume and scatterplot L_fusiform_gyrus_Volume and R_fusiform_gyrus_Volume.
Problem 1.3 (Simulation)

Generate 1,000 standard normal variables and another 1,200 student t distributed random variables with df=20. Generate a quantile-quantile (Q-Q) probability plot of the two samples. Then, compare it with qqnorm of student t simulation and interpret the findings.

 

Problem 1.4 (Define an R median function)

Define a new function  myMedian() that computes a sample median and compare your function against the standard R  median() function using the simulation data you generate in the last question (1.3). Did you cover all possible situations for the input data?

1600487999 09/18/2020 11:59pm

Rubric

Find Rubric
Keep in mind that 39 students have already been assessed using this rubric. Changing it will affect their evaluations.
DSPA Rubric
DSPA Rubric
Criteria Ratings Pts
Edit criterion description
Correctness and scientific validity
threshold: pts
Edit rating Delete rating
50 pts
Full Marks
Edit rating Delete rating
0 pts
No Marks
pts
50 pts
--
Additional Comments
Edit criterion description
Result reproducibility
threshold: pts
Edit rating Delete rating
30 pts
Full Marks
Edit rating Delete rating
0 pts
No Marks
pts
30 pts
--
Additional Comments
Edit criterion description
Content focus, presentaiton style, and clarity
threshold: pts
Edit rating Delete rating
20 pts
Full Marks
Edit rating Delete rating
0 pts
No Marks
pts
20 pts
--
Additional Comments
Total Points: 100 out of 100