%% Homework Week 3

%% If and for statements

% 1. Write a MATLAB program that will display the smaller of two numbers. The two numbers
% should be read in from the user and the program should display the value of the smaller
% number. If the two numbers are equal, either value can be displayed (i.e. don?t worry about
% if the two numbers are equal). 
    

%%
% 2. Using the program from exercise 1 as a starting point, write a MATLAB program that will
% display the smallest of three numbers. The three numbers should be read in from the user
% and the program should display the value of the smallest number. If the two or three
% numbers are equal and are the smallest value, either value can be displayed. Hint: one way
% of solving this problem is to first determine smaller of two of the numbers and then
% compare that result to the third number. 


%%
% 3. A worker is paid according to his hourly wage up to 40 hours, and 50% more for overtime. 
% Write a program in a script file that calculates the pay to a worker. 
% The program asks the user to enter the number of hours and the hourly wage. The program then displays the pay.



%%
% 4. Create a 4 × 8 matrix of uniformly distributed random numbers. 
% Loop through all rows and columns and test whether each element is greater than 0.5. 
% Save a variable that contains the indices of these numbers


%%
% 5. Write a MATLAB program that will display the numbers from 5 to 25 with a step of 5. The
% program should display: 5, 10, 15, 20, and 25. Use iteration (for loop) to solve this problem.
% Run your program and verify that it operates correctly.


%%
% 6. Modify the program of Exercise 5 so that the numbers from 25 to 5 with a step of -5 are
% displayed. The program should display: 25, 20, 15, 10, and 5. Use iteration (for loop) to solve
% this problem. Run your program and verify that it operates correctly.


%% 7. Can you make an infinite loop using a for-loop? How about using an if-then construction?


%% 8. What are the differences between loops A and B below? 
% Which will print out more messages in the Command window? Or will their outputs be the same?
%% loop A
i=0;
while i<5
i=i+1;
    fprintf('%g ',i)
end
fprintf('\n')
%% loop B
i=0;
while i<5
    fprintf('%g ',i)
i=i+1; 
end
fprintf('\n')

%% 9. Write a loop that generates a column vector A with ten random numbers. 
% Then create a 10 × 4 matrix having A as its first column, with the remaining columns 
% the product of the first column and the column number

% a) Using for loops
% b) Using while
% c) what is the difference? 


%% 10. The MATLAB code below ensures that a number read in from the user will be
% greater than zero. Modify the code below to ensure a number between 1 and 100 is
% read in.

% read in number
number = input('Enter number greater than zero: ');
% ensure number is greater than 0
while (number <= 0)
 number = input('Enter number greater than zero: ');
end




%% 11. Write a MATLAB program that will display the name of the month given an integer number
% between 1 and 12 (1 for January, 2 for February, etc.). The number should be read in from
% the user and the program should display the name of the month or an error message if the
% number is not in the range of 1 to 12.


%% 12. Write a MATLAB program that will display a menu with the salgados choices: coxinha, espeto de frango,
% esfirra, e risolis; and display the cost of the salgado selected from the menu. The salgado costs
% are: coxinha R$ 3.50, espeto de frango R$ 3.50, esfirra R$ 3.65, and risolis R$ 3.80. The menu can be generated
% using the MATLAB statement

choice=menu('Salgado Choices','coxinha','espeto de frango','esfirra','risolis');

% The menu generated is shown in Figure 1. The menu function will return an integer
% corresponding to the number of the button selected. The variable choice will be assigned
% the value corresponding to the menu button pressed.