limiter.m 1.13 KB
 Gidon Lucian Bauer committed Mar 19, 2021 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 close all; clear; clc; theta = linspace(-4, 4, 1000); fig = figure(1); fig.WindowState = 'maximized'; hold on; plot(theta, superbee(theta), 'DisplayName', 'superbee'); plot(theta, minmod(theta), 'DisplayName', 'minmod'); plot(theta, vanLeer(theta), 'DisplayName', 'van Leer'); plot(theta, cslimiter(theta), 'DisplayName', 'Čada-Schmidtmann'); title('Limiter functions'); xlabel('\theta'); ylabel('\phi'); legend; hold off; function phi = t3(theta) phi = (2 + theta) / 3; end function phi = cslimiter(theta) phi = zeros(size(theta)); for i = 1:length(theta) phi(i) = max(0, min(t3(theta(i)), max(-theta(i), min(2*theta(i), min(t3(theta(i)), 1.5))))); end end function phi = superbee(theta) phi = zeros(size(theta)); for i = 1:length(theta) phi(i) = max(0, max(min(1, 2*theta(i)), min(2, theta(i)))); end end function phi = minmod(theta) phi = zeros(size(theta)); for i = 1:length(theta) phi(i) = max(0, min(1, theta(i))); end end function phi = vanLeer(theta) phi = zeros(size(theta)); for i = 1:length(theta) phi(i) = (theta(i) + abs(theta(i))) / (1 + theta(i)); end end