Question

Matlab

a) Write a MATLAB code that takes the grade letters from the user and provide him/her with the GPA for that semester Enter your grades (letters): AABBC (input) Your GPA is 3.2 output) b) Write a Matlab user defined function to that takes a letter grade and return a numeric grade as shown in the table below. Any other value should give an error message (Invalid Grade). You function name should be Letter2Grade Use the following information to calculate the GPA. A 4 C 2 D 1 F 0

Answer 1

Code for a:

%Here the grades are read from the user,
% which are separated by spaces,
% the second parameter 's' is used to avoid text evalulation and read the input as it is
grade_str = input('Enter your grades(letters):','s');
% This statement here splits the above string where whitespace is the delimiter,
%and converts it into cell array containing characters
grades = strsplit(grade_str);

%gpa variable which is used to store the average gpa
gpa = 0.0;

% Iterating over the cell array
for k=1:length(grades)
% If the character at grades(1,k) is 'A'
if char(grades(1,k))=='A'
gpa = gpa + 4.0
% Else If the character at grades(1,k) is 'B'
elseif char(grades(1,k))=='B'
gpa = gpa + 3.0
% Else If the character at grades(1,k) is 'C'
elseif char(grades(1,k))=='C'
gpa = gpa + 2.0
% Else If the character at grades(1,k) is 'D'
elseif char(grades(1,k))=='D'
gpa = gpa + 1.0
% Else If the character at grades(1,k) is 'F'
elseif char(grades(1,k))=='F'
gpa = gpa + 0.0
% If it is none of these
else
gpa = gpa + 0.0
end

end

% Calculating the average gpa
gpa = gpa / length(grades)

% Printing the average GPA
disp(sprintf('Your GPA is %.2f', gpa))

OUTPUT:

Enter your grades (letters) : gpa = 4 gpa8 gpa= 11 gpa16 = 3.2000 gpa Your GPA is 3.20

Code for b:

function num_grade = Letter2Grade(letter_grade)

% This function converts a letter grade into a numeric grade.
% If the entered grade is invalid, it returns Invalid grade.

% If the letter_grade is 'A'
if letter_grade=='A'
   num_grade = 4
% If the letter_grade is 'B'
elseif letter_grade=='B'
   num_grade = 3
% If the letter_grade is 'C'
elseif letter_grade=='C'
num_grade = 2
% If the letter_grade is 'D'
elseif letter_grade=='D'
   num_grade = 1
% If the letter_grade is 'F'
elseif letter_grade=='F'
   num_grade = 0
% If it is none of these
else
error('Invalid Grade')
end
end

% Testing the function

Letter2Grade('A')
Letter2Grade('B')
Letter2Grade('C')
Letter2Grade('D')
Letter2Grade('F')
Letter2Grade('Q')

OUTPUT:

octave : 2> function num-grade Letter2G rade(letter-grade) = % This function converts a letter grade into a numeric grade % If the entered grade is invalid, it returns Invalid grade % If the letter grade is 'A' if letter-grade='A num_grade - 4 % If the letter-grade is elseif letter grade-='B' 'B num-grade = 3 % If the letter-grade is elseif letter grade'C' num_grade2 % If the letter-grade is 'D' elseif letter gradeD num_grade1 % If the letter-grade is 'F' elseif letter grade- num-grade % If it is none of these error( 'Invalid Grade') end end octave:3> Letter2Grade ( 'A') num_grade - 4 ans4 octave:4> Letter2Grade ( 'B') num_grade3 ans= 3 octave:5> Letter2Grade( 'C') num_grade2 ans2 octave:6> Letter2Grade('D') num_grade -1 ans1 octave:7> Letter2Grade('F') num-grade θ ans octave:8 Letter2Grade(Q') error: Invalid Grade error: called from Letter2Grade at line 23 column 9