I know why the error is the zeroes?
1 vue (au cours des 30 derniers jours)
Afficher commentaires plus anciens
clear all;
close all;
clc;
dt=0.25;
x=-40:450;
ui=0.5.*exp(-log(2).*(x./3).^2);
figure(1)
plot (x,ui)
xlabel('x-axis')
ylabel('u(x,0)')
xlim([-40 450])
ui=0.5.*exp(-log(2).*((x-400)./3).^2);
figure(2)
plot (x,ui)
xlabel('x-axis')
ylabel('u(x,400)')
xlim([350 450])
ylim([-0.2 0.6])
%%Central difference
unew=zeroes(1,471);
uold=ui;
for j=1:1600
unew(1)=uold(1)-dt*((uold(2)-uold(1))/2);
for i=2:length(ui)-1
unew=uold(i)-dt*((uold(i+1)-uold(i-1))/2);
end
uold=unew;
j*dt;
end
figure
plot(x,ui(x,400))
hold on
plot(x,unew)
hold off
title('central difference @dt=0.25')
Réponses (1)
Hiroki Okawa
le 8 Nov 2019
Modifié(e) : Hiroki Okawa
le 8 Nov 2019
1.
% unew = zeros(1,471);
unew = zeros(size(ui));
2.
% unew=uold(i)-dt*((uold(i+1)-uold(i-1))/2);
unew(i)=uold(i)-dt*((uold(i+1)-uold(i-1))/2);
3.
% plot(x,ui(x,400))
plot(x,ui)
0 commentaires
Voir également
Catégories
En savoir plus sur Graphics Objects dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!