How do I repeat an iteration with newly generated initial conditions if a statement is false? I wrote code that gives me values i need, however if the difference between the values is not smaller than 0.5, I need the loop to restart.

I need help putting all of this into one big loop

1. Guess initial value
2. My code uses the guess to generate multiple T and Z values, these are the imporant ones --> T(5) and Z(4)
3. If T(5) - (20-55/22*Z(4)) < 0.5 is true then plot (x,T) ,
4. If it is false then a new guess needs to be generated using (new guess) = (previous guess) - (previous Z4 value) and put into my code to generate another T(5) and Z(4)
5. The process needs to repeat until step 3 prduces a graph .

This is the code that generates T and Z values

h = 0.01;
A = 8000/11;
T(1)=80;
x(1)=0;
prompt = ('Guess initial Z value');
Z(1) = input(prompt);
 for i=2:5    
    x(i) = x(i-1)+h;
    T(i) = T(i-1) + h*Z(i-1)
    Z(i) = Z(i-1) + h*(A*(T(i-1)-20));
 end

[Prajith Chilummula]

function [T,Z]=genTZ(varargin)

h = 0.01;

A = 8000/11;

T(1)=80;

x(1)=0;

if nargin==0

prompt = ('Guess initial Z value');

Z(1) = input(prompt);

else

Z(1) = varargin(1);

for i=2:5

x(i) = x(i-1)+h;

T(i) = T(i-1) + h*Z(i-1);

Z(i) = Z(i-1) + h*(A*(T(i-1)-20));

end

end

[T,Z]=genTZ();

flag=false;

while ~flag

If T(5) - (20-55/22*Z(4)) < 0.5

plot (x,T);

flag=true;

else

guess=Z(1)-Z(4);

[T,Z]=genTZ(guess);

end

end

I hope the above code helps

[Damian Sztangierski]

Thank you for this, I just tried the code but it says ‘Undefined function or variable ‘genTZ’’ in line 17, how do i get rid of this error?

[Damian Sztangierski]

I have fixed the undefined function issue but now when i run this code i get asked to input the prompt twice and after that i get an error saying the index exceeds matrix dimensions in line 20