1. run_analysis.R only works if you have the original and unaltered "UCI HAR Dataset."
2. You must have the "dplyr" and "tidyr" packages installed.
3. Successful operation was tested on a Windows 7 x64 machine with R 3.1.1 and RStudio 0.98.1062. Successful operation cannot be guaranteed for other operating systems.

This segment will describe how run_analysis.R works line by line.

1. Calling the function

   By default, the dataset is set to "UCI HAR Dataset." The run_analysis function is called either by `run_analysis("UCI HAR Dataset")` or by `run_analysis()`
   

2. Lines 02-05

   Lines 02-05 stops the execution of the function in case "UCI HAR Dataset" does not exist in the working directory
   

3. Lines 07-08

   Lines 07-08 loads the required R packages for the script to function properly
   

4. Lines 01-18

   Lines 10-18 stores each separate dataset directory from "UCI HAR Dataset" in a variable for calling convenience
   

5. Lines 20-28

   Lines 20-28 reads all the datasets from "UCI HAR Dataset" and stores it in separate variables
   

6. Lines 30-40

   Lines 30-40 deal with the cleaning of the column names of the data. Please refer to the accompaying code book for more details. See the section on "Transformations Done on the Original Data" numbers 1-3.
   

7. Lines 42-44

   Lines 42-44 first combines all the student and activity columns to the measurement columns. Then, both the test and train datasets are combined. Please refer to the accompaying code book for more details. See the section on "Transformations Done on the Original Data" numbers 1-3.
   

8. Line 46

   Line 46 updates the column names for the new dataset created from (07) line 44
   

9. Lines 48-49

   Lines 48-49 extracts only the measurements on the mean and standard deviation for each measurement
   

10. Lines 51-55

    Lines 51-55 deal with the cleaning of the column names of the data. Please refer to the accompaying code book for more details. See the section on "Transformations Done on the Original Data" numbers 1-3.
    

11. Lines 57-58

    Lines 57-58 group the data by the subject and activity variables and take the mean for each measurement variable
    

12. Line 60

    Line 60 writes the summarized data to a text file in the working directory as "run_analysis_output.txt"