Trial and Error

Can someone give a example of Matlab codes perform 'trial and error' it will assume certain value , get the answer , error check , in case of suitable result stop the loop ?

Answer 1

[the cyclist]

Here is a simple example. Is this what you mean by "trial and error"?

x = 100;

while x > 1
  x = x-1;
end

x

Answer 2

[Image Analyst]

Make an array with your "certain values" like, for example, choices=[1,2,3,4,100,200,1000] or whatever. Then use randi() to pick an index from that at random. Break out if you selected the value to stop at.

% Define the "certain values"
choices=[1,2,3,4,100,200,1000]
% Tell it to stop if choice #4 is chosen.
choiceToStopAt = choices(4);
for k = 1 : 200
    randomIndex = randi(length(choices), 1);
    selectedChoice = choices(randomIndex);
    fprintf('At experiment %d, randomIndex = %d, selected choice = %d\n',...
        k, randomIndex, selectedChoice);
    if selectedChoice == choiceToStopAt
        fprintf('Stopping because we selected %d\n', choiceToStopAt)
        break;
    end
end

In the command window:

choices =
           1           2           3           4         100         200        1000
At experiment 1, randomIndex = 5, selected choice = 100
At experiment 2, randomIndex = 1, selected choice = 1
At experiment 3, randomIndex = 6, selected choice = 200
At experiment 4, randomIndex = 4, selected choice = 4
Stopping because we selected 4

Answer 3

[Nasir Qazi]

Pn = 0.18; << Assume Value

Phil, Phiv ( is calualted with some equation using above Pn value

Fv=Pn*phiv;

Fl=Pn*phil; (Fl-Fv) < 0.00001

Trail and error command are starting here

(I am seeking help looks like this ) if (Fl-Fv) < 0.00001 <<<< error check so above assume pressure is right and display it if not caluclate another pressure with following relation Pnew = Pn*(phil/phiv); this new pressure will take the place of above assume pressure and again check error check if we got the our error is less then 0.00001 , stop and display the pressure, this is like trial and error and might run in a loop but i dont know how.. need help