trying to get when I say yes it would repeat again and if no it stops the loop, but it would store all the yes values until i say no im like 95% almost done with it just need that part

%%


choice= input('Enter a vector sufficent for an odd-order polynomial:  ');
a=numel(choice);
C = 1;
%b = mod(a,2);
while mod(a,2)~=0
  C=C+1;
  choice= input('Enter a vector sufficent for an odd-order polynomial:  ');
    if C == 5 && mod(a,2)~=0
         warning('Odd number of coefficients entered. Last element removed');
           choice(:,end)=[];
    end
    a=numel(choice);
    
end
   
%Task 2 
while again == 1 
guess=input('Enter an intial guess for the Newton Ralph method: ');
derv = polyder(choice);
b= polyval(derv,guess);
D=1;

while b==0
    D=D+1;
    derv = polyder(choice);
    b= polyval(derv,guess);
    guess=input('Enter an intial guess for the Newton Ralph method: ');
    if D == 3 && b==0
        error('Initial guess causes divide by 0. Program terminated');
    end
end
        
%Task 3
percent_error = 0;

while percent_error<=0.1 || percent_error>=10
      
     percent_error = input('Enter the percent difference to compute [0.1% - 10%]: ');

   
end


%Task 4
 xn=guess-(polyval(choice,guess)./(polyval(polyder(choice),guess)));
 Counter=1;
 Val = [guess,xn];
 while (abs(Val(Counter+1)-Val(Counter))/Val(Counter)).*100 >  percent_error
    Counter=Counter+1;
    xn=Val(Counter)-(polyval(choice,Val(Counter))./(polyval(polyder(choice),Val(Counter))));
    Val(Counter+1) = xn;
 end 
 fprintf('The solution converged in %d iterations',Counter);

 
 %Task 5
F= ["Yes","No"];
again = menu('Repeat newton rsphson calculation?',F);
if again == 2 
end
    


end

[the cyclist]

Responding to your email here.

I made no change to your code. I only put it into "code" format, using the formatting buttons. Maybe you pasted something incorreclty? (I supposed it is possible I inadvertently changed something, but I'm 99.9% sure I did not.)

Because it is your question, you can edit it to fix it, regardless.

[Alex Doan]

Can you help?

Answer 1

[Walter Roberson]

  choice= input('Enter a vector sufficent for an odd-order polynomial:  ');
    if C == 5 && mod(a,2)~=0

As I told you in one of your previous questions, you must adjust a every time you update choice. You did not do so here: you are still working with the number of elements of the previous vector, not the number of elements of the vector that was just entered by the user.