how i can found the region of absolute stability ?
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sadeem alqarni
on 7 Jul 2018
Commented: sadeem alqarni
on 8 Jul 2018
n=0:30:180
h=((768 *cos((1/2)*n) + 96* cos(n) - 864) ./ (40*cos (1/2*n)+ 2*cos(n)+ 102))
figure
plot(n,h, 'b*-', 'LineWidth', 2)
grid on;
xlabel('n', 'FontSize', 20);
ylabel('h', 'FontSize', 20);
Accepted Answer
Image Analyst
on 7 Jul 2018
Because you're using / (array division) instead of ./ (element by element division). Try this:
n=0:30:180
h=((768 *cos((1/2)*n) + 96* cos(n) - 864) ./ (40*cos (1/2*n)+ 2*cos(n)+ 102))
figure
plot(n,h, 'b*-', 'LineWidth', 2)
grid on;
xlabel('n', 'FontSize', 20);
ylabel('h', 'FontSize', 20);
% Do it again with more resolution.
n = linspace(min(n), max(n), 1000);
h=((768 *cos((1/2)*n) + 96* cos(n) - 864) ./ (40*cos (1/2*n)+ 2*cos(n)+ 102))
hold on;
plot(n,h, 'r-', 'LineWidth', 2)
grid on;
xlabel('n', 'FontSize', 20);
ylabel('h', 'FontSize', 20);
More Answers (2)
sadeem alqarni
on 8 Jul 2018
2 Comments
Image Analyst
on 8 Jul 2018
How is this an "Answer" to your original question? Anyway, as you can see from my plot, it depends on how you define stable. The values are constantly changing so they're not stable, however the overall pattern seems pretty stable - it seems to oscillate pretty much the same way over the time period plotted.
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