One condition is not being fulfilled, and suddenly when i wrote on command window, give me a infinite menu, and i can not close it

Hello, in this program that I'm building, when b1==2, there is no fulfillment of that condition, and when I write in the window command, later an infinite menu appears... I don't understand why, I've tried everything and I don't understand because my idea is not working.

So the problem begins when the user chose: 'Manually'

If u respond on input 'a1' : 2, it´s not giving what it´s in the code, it gives me the condition b1==1, and appears the menu that i talked earlier.

please help, the code it´s:

clc, clear, close



while true
     a=menu({'This program allows the fitting of functions to experimental points.', ...
     'To start the program, click on the Start button.'},'Start','Exit');
%Operation of menu a

if a==1
  b= menu('How do you intend to insert the experimental points?', ...
             'By a file','Manually','Back','Exit');
end
if a==2
     break
end

%Operation of the menu b
if b==1

elseif b==2
     a1= sprintf('If you want to advance in the program, press 1.\n If you want to go back to the previous menu, press 2: ');
   b1= input(a1);
     p = input('How many experimental values do you want to insert?: ');

     if b1==1

while p < 2 && p <= 0
  errordlg ({'The number of experimental points must be at least 2.','Please press Ok and enter the desired value in the Command Window.'})
p = input('How many experimental values do you want to insert?: ');

end

n = p/2; %Number of matrix rows
m = 2; %Number of matrix columns
a = zeros(n,m); %prelocation


for i=1:n
     for j=1:m
         if (j == 1)
             fprintf('Enter the %0.0fᵒ ',i)
             a(i,j)= input('value of x: ');
         else
             fprintf('Enter the %0.0fᵒ ',i)
             a(i,j)= input('value of y: ');
         end
     end
end

a=reshape(a,n,m); %Matrix according to the number of rows and columns
disp(a); %Matrix according to the number of rows and columns

     end

if b1==2
         clc
      b= menu('How do you intend to insert the experimental points?', ...
             'By a file','Manually','Back','Exit');
     else
         disp('The number entered was not correct')
end

if b==3
  a=menu({'This program allows the fitting of functions to experimental points.', ...
     'To start the program, click on the Start button.'},'Start','Exit');
if b==4
     break

end
end
end
end

[Stephen23]

One of the changes that VBBV did, is to align the code consistently. Poorly aligned code hides the structure of the code, which makes it harder to understand (i.e. increases the risk of bugs and makes it harder to debug). You should consistently align your code. Note that the MATLAB editor can do this for you: select all code, press ctrl + i

[Madalena Francisco]

Wow and that´s amazing, I didn't know about that, thanks a lot Stephen! I have a Mac, where should i press? Thank u thank u!!

Answer 1

[VBBV]

clc, clear, close



while true
    a=menu({'This program allows the fitting of functions to experimental points.', ...
        'To start the program, click on the Start button.'},'Start','Exit');
    %Operation of menu a

    if a==1
        b= menu('How do you intend to insert the experimental points?', ...
            'By a file','Manually','Back','Exit');
    end
    if a==2
        break
    end

    %Operation of the menu b
    if b==1
       disp('Insert a file')
    elseif b==2
        a1 = input('If you want to advance in the program, press 1.\n If you want to go back to the previous menu, press 2: ');
        b1 = a1 ;
        
        if b1==1
            p = input('How many experimental values do you want to insert?: ');  % this statement 

            while p < 2 && p <= 0
                errordlg ({'The number of experimental points must be at least 2.','Please press Ok and enter the desired value in the Command Window.'})
                p = input('How many experimental values do you want to insert?: ');

            end

            n = p/2; %Number of matrix rows
            m = 2; %Number of matrix columns
            a = zeros(n,m); %prelocation


            for i=1:n
                for j=1:m
                    if (j == 1)
                        fprintf('Enter the %0.0fᵒ ',i)
                        a(i,j)= input('value of x: ');
                    else
                        fprintf('Enter the %0.0fᵒ ',i)
                        a(i,j)= input('value of y: ');
                    end
                end
            end

            a=reshape(a,n,m); %Matrix according to the number of rows and columns
            disp(a); %Matrix according to the number of rows and columns

        elseif b1==2
            clear b
            b  = menu('How do you intend to insert the experimental points?', ...
                'By a file','Manually','Back','Exit');
        else
            disp('The number entered was not correct')
        end

    elseif b==3
        a=menu({'This program allows the fitting of functions to experimental points.', ...
            'To start the program, click on the Start button.'},'Start','Exit');
    elseif b==4
        break

    end
end

[Madalena Francisco]

Thank u so much!!! But it keeps not reading the condition when b1==2

[Madalena Francisco]

and the elseif solved something!! thank u

[Madalena Francisco]

when it´s asked: If you want to advance in the program, press 1.\n If you want to go back to the previous menu, press 2: '

when the user put´s 2, it´s not giving what it´s in the code

you can help me please?

[VBBV]

Check the below code ,

clc, clear, close
while true
    a=menu({'This program allows the fitting of functions to experimental points.', ...
        'To start the program, click on the Start button.'},'Start','Exit');
    %Operation of menu a

    if a==1
        b= menu('How do you intend to insert the experimental points?', ...
            'By a file','Manually','Back','Exit');
    end
    if a==2
        break
    end

    %Operation of the menu b
    if b==1
       disp('Insert a file')
    elseif b==2
        a1 = input('If you want to advance in the program, press 1.\n If you want to go back to the previous menu, press 2: ');
        b1 = a1 ;
        
        if b1==1
            p = input('How many experimental values do you want to insert?: ');

            while p < 2 && p <= 0
                errordlg ({'The number of experimental points must be at least 2.','Please press Ok and enter the desired value in the Command Window.'})
                p = input('How many experimental values do you want to insert?: ');

            end

            n = p/2; %Number of matrix rows
            m = 2; %Number of matrix columns
            a = zeros(n,m); %prelocation


            for i=1:n
                for j=1:m
                    if (j == 1)
                        fprintf('Enter the %0.0fᵒ ',i)
                        a(i,j)= input('value of x: ');
                    else
                        fprintf('Enter the %0.0fᵒ ',i)
                        a(i,j)= input('value of y: ');
                    end
                end
            end

            a=reshape(a,n,m); %Matrix according to the number of rows and columns
            disp(a); %Matrix according to the number of rows and columns

        elseif b1==2
            clc
            b  = menu('How do you intend to insert the experimental points?', ...
                'By a file','Manually','Back','Exit');
        else
            disp('The number entered was not correct')
        end

    elseif b==3
        a=menu({'This program allows the fitting of functions to experimental points.', ...
            'To start the program, click on the Start button.'},'Start','Exit');
    elseif b==4
        break

    end
end

[VBBV]

Few more changes, necessary if the user selects 1 or 2, these line

p = input('How many experimental values do you want to insert?: ');

needs to be inside the

if b1 == 1  % condition

[VBBV]

There are few other errors in condition checks e.g.

if  p >= 0  & p < 2  % this condition in while can be changed to if-end
    errordlg ({'The number of experimental points must be at least 2.','Please press Ok and enter the desired value in the Command Window.'})
    p = input('How many experimental values do you want to insert?: '); 
end
n = round(p/2); % this will throw error 

[Madalena Francisco]

Wow it really works!! Thanks a lot VBBV! Words aren't enough to thank u!!!

But know i´m facing other problem...if the user inputs: 2, now it will appear like i wanted, the menu b, deep deep thanks for that, but in that menu, when i click in 'Exit', doesn't do what is in the condition:

    elseif b==4
        break

It appears the menu a, and just when i click on 'Exit' on menu a, the menu really closed, but i wanted to close following the instructions that i wrote.

The:

          elseif b==4
        break

Works when the user see the menu for the first time, but if the user see this menu, when inputs 2 , like i wanted, it doesn´t, like I explain earlier.

Can you help please? Big thanks, for everything!!

[VBBV]

Add another if-end condition inside the elseif b1 == 2 section as shown below

elseif b1==2
    clc
    b  = menu('How do you intend to insert the experimental points?', ...
        'By a file','Manually','Back','Exit');
    if b == 4
        break;
    end

else
    disp('The number entered was not correct')
end

This should work as expected

[Madalena Francisco]

Ohhh okok thank u I will add it!! It works!!

But why the program doesn´t recognize the earlier condition? Why I need to write a condition that I already wrote? The program shouldn´t recognize it in the first place?

And now when the user see the menu for the fisrt time, and click on 'Exit' (menu b), appears the menu a, and doesn't recognize the condition:

if b == 4
        break
end

I need to put this condition inside if a==1 ?

I don't understand when I should repeat conditions!

Thank u for ur help, I´m learning a lot!

[VBBV]

Yes, you can put the condition inside

if a==1
    b= menu('How do you intend to insert the experimental points?', ...
        'By a file','Manually','Back','Exit');
        if b == 4
              break
        end
end

When the user clicks the "Exit" button, the value assigned to b will be 4. At this time, the program control still remains inside the if statement

% similarly in below condiion  
elseif b1==2
    clc
    b  = menu('How do you intend to insert the experimental points?', ...
        'By a file','Manually','Back','Exit');
    if b == 4
        break;
    end
else
    disp('The number entered was not correct')
end

So the menu action for "Exit" button stops unless you specify a way for program control to be returned to main menu. .

[Madalena Francisco]

Thank u so much again!! Wow! And I let the final if b==4?

        elseif b1==2
            clear b
            b  = menu('How do you intend to insert the experimental points?', ...
                'By a file','Manually','Back','Exit');
                if b == 4 % i added this one and it works!
        break
    end
        else
            disp('The number entered was not correct')
        end
    elseif b==3
        a=menu({'This program allows the fitting of functions to experimental points.', ...
            'To start the program, click on the Start button.'},'Start','Exit');
    elseif b==4 % but i need this one too right? 
        % Or i need to put below every b menu to close the program?
        
        break
    end
end

[Madalena Francisco]

Ok I think I understand... if I want the statments to work in each menu, their have to be below the menu is that it?