Question

Correct all errors in the provided script. Remember that some errors are fatal (result in an error message) while others simply cause the program to produce incorrect results.

You can assume that you have fixed all errors when the checker passes all tests.

%***************************************************************************************

%It is recommended that you debug this program offline and submit only once you have corrected the errors

%***************************************************************************************

%%

%These 3 loops all calculate the sum of the integers from 1 through 1000

for number = 1:1000

total = total + number;

end

fprintf('The sum of the numbers from 1 through 1000 is %i\n', total);

k=0;

theTotal = 0;

while k <1000

theTotal = theTotal + k;

end

fprintf('The sum of the numbers from 1 through 1000 is %i\n', theTotal);

theTotal_2 = 0;

while k >1000

theTotal_2 = theTotal_2 + k;

k = k-1;

end

fprintf('The sum of the numbers from 1 through 1000 is %i\n', theTotal);

%%

%These structures all do the same thing - find the roots of a quadratic,

%and print out the real roots, if any

a = 1;

b = 3;

c = 2;

discriminant = b^2 - 4ac;

if discriminant > 0

root1 = (-b+sqrt(b^2 - 4*a*c))/(2*a);

root2 = (-b-sqrt(b^2 - 4*a*c))/(2*a);

fprintf('The roots are %f and %f\n', root1, root2);

elseif discriminant == 0

root1 = -b/(2*a);

root2 = NaN;

fprintf('The root is %f and %f\n', root1);

else

fprintf('There are no real roots\n');

end

aa = 1;

bb = -8;

cc = 16;

discriminant = bb^2 - 4*aa*cc;

switch discriminant

case discriminant>0

root3 = (-bb+sqrt(bb^2 - 4*aa*cc))/(2*aa);

root4 = (-bb-sqrt(bb^2 - 4*aa*cc))/(2*aa);

fprintf('The roots are %f and %f\n', root3, root4);

case discriminant == 0

root3 = -b/(2*a);

root4 = NaN;

fprintf('The root is %f\n', root3);

otherwise

fprintf('There are no real roots\n');

end

%%

%This program calculates and plots the Fibonacci numbers that are less than

%100

fibonacciNumber=[1, 1];

%first time through the loop, calculating the 3rd Fibonacci number

index = 3;

while fibonacciNumber < 100

fibonacciNumber(end+1) = fibonacciNumber(end) + fibonacciNumber(end-1);

index = index + 1;

end

try

assert(sum(fibonacciNumber>=100)==0)

%The following lines will only be executed if the assertion passes

fprintf('There are %i Fibonacci numbers that are less than 100;', length(fibonacciNumber));

fprintf('They are: \n')

fprintf('%i\n', fibonacciNumber);

plot(1:index, fibonacciNumber)

catch ME

switch ME.identifier

case 'MATLAB:assertion:failed'

disp('Incorrect set of Fibonnaci numbers.')

case 'MATLAB:samelen'

disp('error in plot - vectors not the same length')

otherwise

disp('Something is wrong with the Fibonacci number code')

end

end

%%

%This program calls the user-defined function, GPA() to calculate a

%student's grade point average

Grades = 'ABACAABBDAC';

Credits = [43454453324];

Name = "Joe";

GPAValue = gradePointAverage(grades, credits);

fprintf('%s''s GPA is %d\n', GPAValue);

function [ gradePointAverage] = GPA(letterGrades, numCredits )

%UNTITLED3 Summary of this function goes here

% Detailed explanation goes here

qualityPoints = (letterGrades=='A')*4 + (letterGrades=='B')*3 + (letterGrades=='C')*2 + (letterGrades=='D')*1;

totalPoints = sum(qualityPoints.*credits);

gradePointAverage = totalPoints/sum(credits);

end

Answer 1

Question 1

%%
%These 3 loops all calculate the sum of the integers from 1 through 1000
total=0;
for number = 1:1000
   total = total + number;
end
fprintf('The sum of the numbers from 1 through 1000 is %i\n', total);

k=0;
theTotal = 0;
while k <=1000
   theTotal = theTotal + k;
    k+=1;
end
fprintf('The sum of the numbers from 1 through 1000 is %i\n', theTotal);
theTotal_2 = 0;
k=k-1;
while k >0
   theTotal_2 = theTotal_2 + k;
    k = k-1;
end
fprintf('The sum of the numbers from 1 through 1000 is %i\n', theTotal_2);
%%

Output

The sum of the numbers from 1 through 1000 is 500500
The sum of the numbers from 1 through 1000 is 500500
The sum of the numbers from 1 through 1000 is 500500

--------------------------------------------------------------------------------------

Question 2

%%
%These structures all do the same thing - find the roots of a quadratic,
%and print out the real roots, if any
a = 1;
b = 3;
c = 2;
discriminant = b^2 - 4*a*c;
if discriminant > 0
    root1 = (-b+sqrt(b^2 - 4*a*c))/(2*a);
    root2 = (-b-sqrt(b^2 - 4*a*c))/(2*a);
    fprintf('The roots are %f and %f\n', root1, root2);

elseif discriminant == 0
    root1 = -b/(2*a);
    root2 = NaN;
    fprintf('The root is %f and %f\n', root1);
else
    fprintf('There are no real roots\n');
end
aa = 1;
bb = -8;
cc = 16;
discriminant = bb^2 - 4*aa*cc;
switch true
    case discriminant>0
        root3 = (-bb+sqrt(bb^2 - 4*aa*cc))/(2*aa);
        root4 = (-bb-sqrt(bb^2 - 4*aa*cc))/(2*aa);
        fprintf('The roots are %f and %f\n', root3, root4);
    case discriminant == 0
         root3 = -bb/(2*aa);
         root4 = NaN;
         fprintf('The root is %f\n', root3);
    otherwise
         fprintf('There are no real roots\n');
end
%%

Output

The roots are -1.000000 and -2.000000
The root is 4.000000

------------------------------------------------------------------------------------

Question 3

%%
%This program calculates and plots the Fibonacci numbers that are less than
%100
fibonacciNumber=[1, 1];
%first time through the loop, calculating the 3rd Fibonacci number
index = 2;
while true
    val = fibonacciNumber(end) + fibonacciNumber(end-1);
    if(val<100)
        fibonacciNumber(end+1) =val;
    else
       break;
    end
   index = index + 1;
end
try
    assert(fibonacciNumber(end)<100)
    %The following lines will only be executed if the assertion passes
    fprintf('There are %i Fibonacci numbers that are less than 100;', length(fibonacciNumber));
    fprintf('They are: \n')
    fprintf('%i\n', fibonacciNumber);
    plot(1:index, fibonacciNumber)
catch ME
    switch ME.identifier
       case 'MATLAB:assertion:failed'
            disp('Incorrect set of Fibonnaci numbers.')
       case 'MATLAB:samelen'
            disp('error in plot - vectors not the same length')
       otherwise
            disp('Something is wrong with the Fibonacci number code')
    end
end
%%

Output

There are 11 Fibonacci numbers that are less than 100;They are: 
1
1
2
3
5
8
13
21
34
55
89

-------------------------------------------------------------------------------------------------------------------

Question 4

%%
%This program calls the user-defined function, GPA() to calculate a
%student's grade point average
Grades = 'ABACAABBDAC';
Credits = [43454453324];
function [ gradePointAverage] = GPA(letterGrades, numCredits )
%UNTITLED3 Summary of this function goes here
% Detailed explanation goes here
qualityPoints = (letterGrades=='A')*4 + (letterGrades=='B')*3 + (letterGrades=='C')*2 + (letterGrades=='D')*1;
totalPoints=0;
for i=1:size(qualityPoints)
    totalPoints=totalPoints+(qualityPoints(i)*numCredits(i));
end
gradePointAverage = totalPoints/sum(numCredits);
end
Name = "Joe";
GPAValue = GPA(Grades, Credits);
fprintf('%s''s GPA is %d\n',Name, GPAValue);
%%

Output

Joe's GPA is 4