Hi Chao,
As per my understanding you want to reduce the time for creating the plot. The script is indeed computationally intensive. You can replace your script with the following code that will generate the .pdf file as well as the figure.
figure;
f = @(x) pi/4;
for n = 1:15
f = @(x) f(x) + (1-(-1)^n)/(n^2*pi)*cos(n*x) + 1/n*sin(n*x);
end
x = linspace(-15, 15, 10000); % Generate points between -15 and 15
y = f(x); % Evaluate the function for the given x values
plot(x, y, 'b');
% code to generate pdf
set(gcf,'Units','inches');
screenposition = get(gcf,'Position');
set(gcf,...
'PaperPosition',[0 0 screenposition(3:4)],...
'PaperSize',[screenposition(3:4)]);
print -dpdf -painters fig
% code to generate pdf ends
xlabel('x');
ylabel('f(x)');
legend('k=15', 'Location', 'southeast');
ylim([-2 4])
The line where "linspace" function is used, you can change the value of "10000" to other numbers and check which one gives you the appropriate plot.
I hope this helps!
