I have a matlab homework assignment to build a grade calculator in matlab.First time coding and in need of some help!

I need the program to take a range of inputs in matrix form and return a letter grade. 0-59.99=F 60-69.99=D, etc. The program needs to discard negative grades, and calculate all of the following:

• ○ Numeric mean (class average)
• ○ Average letter grade for the class
• ○ Standard deviation of the grades
• ○ Highest numeric grade
• ○ Lowest numeric grade

Any help would be appreciated: here is what I have thus far:

enter=1;
grade=[];
t=1;

while enter==1

      grades(t) = input ('Please enter a grade');

      if grades(t) < 59.99 && grades(t) >= 0 
          disp ('F')

      elseif grades(t) >= 60 && grades(t) <= 69.99 
          disp ('D')

          elseif grades(t) >= 70 && grades(t) >= 79.99 
              disp ('C')

              elseif grades(t) >= 80 && grades(t) >= 89.99 
                  disp ('B')

                  elseif grades(t) >= 90 && grades(t) >= 100 
                      disp ('A')

                          if grades(t) <= 0 disp (N/A)
                          end

[Geoff Hayes]

Brian - how does the user exit the phase where she enters in the grades? Your condition on the while loop is

 enter==1

so how would this get set to zero? Your also not checking for negative grades until after you have added this to the grades array. Instead you should this value before you add it to the array since you won't want to include it in any of your calculations:

 while enter == 1
     newGrade = input('Please enter a grade: ');
     if newGrade >= 0
         grades(t) = newGrade;
         t = t + 1;
         % etc.
     end
 end

You also mention ...take a range of inputs in matrix form and return a letter grade... So does the user enter an array of grades or one by one like how you have coded? Please clarify.

[Brian Mabe]

The user will be entering grades one at a time. After they have no more grades left to input, they will enter "0". Then the code should hold onto the set of numeric entries, store them as a matrix, and express the average as a letter grade equivalent.

I also need to write a second script to calculate mean, median, mode, standard deviation etc., HOWEVER, I am not allowed to use operators like std.

Thank you, in advance, for your advice!

[Nstaub]

I would suggest to be careful with your input because user can input a string which will mess up your tests. Also I prefer fprintf to disp function as you get more control on the string output. my 2 cents