Introduction

This is a demonstration of an R package library(myPackage) that I am in the process of developing. The purpose of this package was two-fold:

1. To demonstrate how to develop a package to undergraduate students at University of Toronto.
2. To facilitate the ease in transform variables for grades as an course instructor for several undergraduate statistics. courses.

myPackage

For each course I teach my syllabus states that for those absences that are documented, the student will receive a value of “-1” as a place holder grader. This is to avoid the confusion of assigning a grade between 0 to 100. For students without a noted absence their cell remains empty, and when transcribed into R, it is read as “NA.”

When I process the grades for the final exam the first thing I do is convert “-1” to “NA” and “NA” to “0” in order to remove the exempt students from the assessment and assign a grade of 0 to those who did not have a noted absence. Therefore myPackage contains two things:

1. A function new.grades that takes a vector of length (n) and returns another vector of length (n) that translates “NA” to “0” and “-1” to “NA.”
2. A data set called Grades of term test grades from a past statistics course that is stripped of any identifiable information.
3. Upcoming: A function called reweighted that will re-weighted the grading scheme for “NA” cases based on the remaining components in the course.

Demonstration

library(myPackage)
head(Grades)
#>   Term Test 1 (/505) Term Test 1 Adjust (/50) Term Test 2 (/57)
#> 1                 34                       36                40
#> 2                 36                       38                42
#> 3                 26                       28                29
#> 4                 45                       47                48
#> 5                 18                       20                -1
#> 6                 34                       36                40
#>   Term Test 2 Adjust (/55)
#> 1                       40
#> 2                       42
#> 3                       29
#> 4                       48
#> 5                       -1
#> 6                       40
attach(Grades)

The first variable consists of the unadjusted term test 1 grades (TT1) (out of 50) for a third year statistics course. Since every student either took the term test, or had a documented absence, the vector does not contain any “NAs.”

TT1=`Term Test 1 (/505)`
tail(TT1, 20)
#>  [1] 36 43 41 20 -1 40 36 29 40 41 23 36 34 23 32 37 22 17 39 43

The following command will transform the last 20 variables that were displayed for the unadjusted TT1 grades.

TT1_new=new.grades(TT1)
tail(TT1_new, 20)
#>  [1] "36" "43" "41" "20" "NA" "40" "36" "29" "40" "41" "23" "36" "34" "23" "32"
#> [16] "37" "22" "17" "39" "43"

This presents the numbers as a string. In order to work with the variables in any kind of quantitative analysis, I would have to use build in functions in base R such as the as.numeric function.