2 Program specifications In the following, the specifications for...

2 Program specifications
In the following, the specifications for the program will be covered, i.e. the required functions and the main script. Note that the specifications are not exhaustive, and some challenges have been left for you to identify, solve, implement, and document. This is done on purpose; we want to see you make your own decisions and see how you choose to handle the problems you encounter. It is perfectly acceptable for you to make your own choices when something is not covered by the specifications. Do note that your choices must be documented and your arguments for making those choices will be evaluated.
General requirements
Each function must be implemented according to the given interface and may not be implemented as a script. It is allowed to use sub-functions and built-in functions within a function.
The main script must be implemented according to the given specifications. It is not allowed to implement the main script as a function.
It is not allowed to invoke (call) scripts within another script or within a function. You may only implement one script, namely the the main script.
You may develop additional "helper" functions that are called from within in the main script and/or from the other functions, if you believe this will result in a more elegant or practicalsolution. Make sure to address design choices such as these in your report.
You are allowed to use built-in functions, and you are encouraged to explore if there exists built-in functions that you can use in your own code, and document your findings in the report.
All functions must contain appropriate help text describing the purpose of the function, the input and output arguments, how the function is used, as well as other information that is necessary to understand and use the function. It is recommended to use the structure of the help text in the built-in functions as inspiration.
Excessive error handling within a function may lead to a decrease in computational performance, especially if the function is called often. For this reason, it is often best practice to assume that input arguments for a function are valid (and state in the help text what requirements there are to the arguments.) Note that this does not cover interactive user input. You must error check interactive user input within the scope where it is passed to the program.

2.1 Grade rounding function
Interface             function gradesRounded = roundGrade (grades)
                                  % Insert your code here
Input arguments grades: A vector (each element is a number between -3 and 12).
Output arguments          gradesRounded: A vector (each element is a number on the 7-step-scale).
User input                   No.
Screen output             No.
Description
The function must round off each element in the vector grades and return the nearest grade on the 7-step-scale:
7-step-scale: Grades 12 10 7 4 02 00 -3
For example, if the function gets the vector [8.2, -0.5] as input, it must return the rounded grades [7, 0] which are the closest numbers on the grading scale.

2.2 Final grade function
Interface                   function gradesFinal = computeFinalGrades (grades)
                                 % Insert your code here
Input arguments       grades: An N X M matrix containing grades on the 7-step-scale given to N students on M different assignments.
Output arguments    gradesFinal: A vector of length n containing the final grade for each of the N students.
User input                  No.
Screen output            No.
Description                For each student, the final grade must be computed in the following way:
1. If there is only one assignment (M = 1) the final grade is equal to the grade of that assignment.
2. If there are two or more assignments (M > 1) the lowest grade is discarded. The final grade is computed as the mean of M - 1 highest grades rounded to the nearest grade on the scale (using the function roundGrade).
3. Irrespective of the above, if a student has received the grade - -3 in one or more assignments, the final grade must always be - 3.


2.3 Grades plot function
Interface                  function gradesP] lot (grades)
                               % Insert your code here
Input arguments      grades: An N X M matrix containing grades on the 7-step-scale given to N students on M different assignments.
Output arguments    No.
User input                No.
Screen output          Yes (plots, see specifications below.)
Description
This function must display two plots:
1. "Final grades": A bar plot of the number of students who have received each of possible final grades on the 7-step-scale (computed using the function computeGradesFinal).
2. "Grades per assignment": A plot with the assignments on the x-axis and the grades on the y-axis. The x-axis must go from 1 to M, and the y-axis must go from -3 - to 12. The plot must contain:
   1. Each of the given grades marked by a dot. You must add a small random number (between -0.1 and 0.1) to the X- and y-coordinates of each dot, to be able tell apart the different dots which otherwise would be on top of each other when more than one student has received the same grade in the same assignment.
   2. The average grade of each of the assignments plotted as a line The plots should include a suitable title, descriptive axis labels, and a data leg- end where appropriate. You are allowed to present the plots in separate figure windows or as sub-plots in a single figure window.

2.4 Main script
Interface                         Must be implemented as a script.
Input arguments             No.
Output arguments          No.
User input                        Yes (see specifications below.)
Screen output                  Yes (see specifications below.)
Description
When the user runs the main script he/she must first be asked to enter the name of a comma-separated-values (CSV) file containing grades given to a number of students for a number of assignments (see description of file format below).
Remember to check if the file name is valid. After reading in the data, you must display some information about the loaded data, including at least the number of students and the number of assignments.
Next, the user must have at least the following options:
1. Load new data.
2. Check for data errors.
3. Generate plots.
4. Display list of grades.
5. Quit.
The user must be allowed to perform these actions (see specifications below) in any order as long as he/she chooses, until the user decides to quit the program. The details of how the main script is designed and implemented is for you to determine. It is a requirement that the program is interactive, and you should strive to make it user friendly by providing sensible dialogue options. Consider what you would expect if you were to use such a script, and what you think would be fun. Play around and make a cool script.
File format
The first row in the CSV file will contain the column headings. Each of the following rows will contain a student id, a name, and a number of grades for a student. An example of a data file with four students and three assignments is given below:
StudentID, Name,         Assignment1, Assignment2, Assignment3
s123456,   Michael Andersen,    7,                7,                4
s123789,   Bettina Petersen,    12,             10,               10
s123468,   Thomas Nielsen,      -3,                7,                2
s123579,   Marie Hansen,          10,             12,               12
Remember that your program should work for any number of students and any number of assignments. You are encouraged to make your own test data file in order to validate that your program functions correctly.
Error handling
You must test that all input provided by the user are valid. If the user gives invalid input, you must provide informative feedback to the user and allow the user to provide the correct input.

1. Load new data
If the user chooses to load new data, the user must be asked to input a valid filename of a data file, and data must be loaded in the same way as in the beginning of the script.
2. Check for data errors If the user chooses to check for data errors, you must display a report of errors (if any) in the loaded data file. Your program must at least detect and display information about the following possible errors:
1. If two students in the data have the same student id.
2. If a grade in the data set is not one of the possible grades on the 7-step- scale.
3. Generate plots
If the user chooses to generate plots, call the gradesPlot function to display the plots.
4. Display list of grades If the user chooses to display the list of grades, you must display the grades for each assignment as well as the final grade for all of the students in alphabetical order by their name. The displayed list must be formatted in a way SO that it is easy to read.
5. Quit
If the user chooses to quit the program, the main script should stop.