# how to make a plot from my function results?

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Chris ch on 13 May 2020
Edited: the cyclist on 13 May 2020
How to make a plot from my function results?
(My function finds pi_aprox with a method and calculates the error from pi every time,it calculate for n times) i want to plot (error) and (n). From that plot we will see that inreasing n the error will be decreased.
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Chris ch on 13 May 2020
Ty for your answer , cause i am new in matlab ,how to write this ?

the cyclist on 13 May 2020
Edited: the cyclist on 13 May 2020
Here is an example using a for loop that calculates and plots the Gregory-Leibinz approximation to pi:
n_max = 100;
pi_approx = zeros(n_max,1);
pi_approx(1) = 4/1;
for n = 2:n_max
factor = (-1)^(n-1) / (2*n - 1);
pi_approx(n) = pi_approx(n-1) + 4*factor;
end
figure
plot(1:n_max,pi_approx - pi)
Here is an equivalent vectorized version:
n = 1:100;
factor = 4 * (-1).^(n-1) ./ (2*n - 1);
pi_approx = cumsum(factor);
figure
plot(1:n_max,pi_approx - pi)