How to plot for a matrix?
1 vue (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Westin Messer
le 6 Nov 2018
Réponse apportée : Stephen23
le 6 Nov 2018
Hello, in this code I am varying the parameter k from 1 to 4 and I get four different sets of numbers for u and v. I want to plot all sets of these numbers on the same graph so I should get multiple lines. However, when I run it, it only plots for one set of values. Does anyone know how to fix this? Thanks!
%Clear command window and workspace
clear
close all
clc
% Fitzhugh-Nagoma model parameters
e=0.01; k=1:1:4; a=0.1;
i = 0.001;
figure(1);
hold on
u=zeros(500000,4);
v=zeros(500000,4);
t=zeros(100000,1);
% Initial conditions:
u(:)=0.3;
v(:)=0.0;
t(1)=0;
dt=0.001;
%==========================================================================
% Forvard Euler Method, for soluing the ODE
%==========================================================================
for k=1:4
for i=1:1:500000
t(i+1)=t(i)+dt;
% u(i+1) = u(i)+ dt*((1/e)*((k(:)*u(i)*(u(i)-a)*(1-u(i)))-v(i)));
u(i+1,:) = u(i,:)+ dt.*((1/e).*((k.*(u(i,:).*(u(i,:)-a).*(1-u(i,:))))-v(i)));
v(i+1,:) = v(i,:)+ dt*(u(i)-v(i));
end
end
% Getting the phase plot
figure(1);
upts=(-2:.05:2);
unullpts=(k*upts.*(upts-a).*(1-upts));
vnullpts=upts;
plot(upts,unullpts,'black',upts,vnullpts,'black');
xlabel('u'); ylabel('v');
axis([-1 2 -1.5 5]);
plot(u,v,'b')
title('Nullcline Plot')
xlabel('u')
ylabel('v')
0 commentaires
Réponse acceptée
Stephen23
le 6 Nov 2018
You for to use the index k from the outer loop:
% Fitzhugh-Nagoma model parameters
e = 0.01;
k = 1:1:4;
a = 0.1;
i = 0.001;
u=zeros(5000,4);
v=zeros(5000,4);
t=zeros(1000,1);
% Initial conditions:
u(:)=0.3;
v(:)=0.0;
t(1)=0;
dt=0.001;
%
for k=1:4
for i=1:1:5000
t(i+1)=t(i)+dt;
u(i+1,k) = u(i,k)+ dt.*((1/e).*((k.*(u(i,k).*(u(i,k)-a).*(1-u(i,k))))-v(i)));
v(i+1,k) = v(i,k)+ dt*(u(i,k)-v(i,k));
end % ^ ^ ^ ^ you forgot to use |k|.
end
plot(t,u,'r', t,v,'b')
Gives:
0 commentaires
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Loops and Conditional Statements 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!