# Creating table with all iterations of function

2 views (last 30 days)
Oliver on 13 Oct 2022
Answered: Amey Waghmare on 20 Oct 2022
I am trying to run this code and get it to show each of the iterations for the function up until itmax = 4. Any idea how I can get it to print separate iterations in the same table using the code I have as of now?
es = 1E-6; % Stopping criterion (%).
itmax = 4; % Maximum number of iterations.
xl = 0.5; % Initial lower bound of the interval.
xu = 1; % Initial upper bound of the interval.
xr = 0.8; % Initial approximation of the root.
fx = @(x) sin(x) - (x.^2); % Function of interest.
for it = 1:itmax
xrold = xr;
xr =(xl+xu)/2; % Approximation of the root.
if (xr~=0)
ea = abs((xr-xrold)/xr)*100; % Approximate relative error.
end
test = fx(xl)*fx(xr); % Half-interval test.
if (test<0)
xu=xr;
elseif (test>0)
xl=xr;
else
ea = 0;
end
if (ea<=es), break, end
end
disp('Bisection method results:')
Bisection method results:
root = xr; % Estimated root via the Bisection method when converge
func = fx(xr); % Function value at the estimated root
ea; % Relative error
T = table(root', func', ea', 'VariableNames', {'Root Value', 'Function Value', 'Relative Error'})
T = 1×3 table
Root Value Function Value Relative Error __________ ______________ ______________ 0.90625 -0.034092 3.4483

Amey Waghmare on 20 Oct 2022
Hi,
As per my understanding, you are trying to display the values of variables root, func and ea in the Table T for each iteration.
In order to store the values for each variable, you can initialize an empty array for each variable at the beginning of the code using:
xr_arr = zeros(1, itmax);
where the index of the array corresponds to the iteration number, and then update values at each index in the for loop using:
xr_arr(it) = xr;
At the end when you are creating the table, you can pass xr_arr instead of xr to the table function. Similar workflow can be done for other variables in your code.
I hope this resolves the issue.

### Categories

Find more on Logical in Help Center and File Exchange

R2022a

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!