I have problem in solving ode45

clear all, close all, clc

w=2*pi;

zeta=0.25;

A=[0 1;-w^2 -zeta];

dt=0.01;

T=10;

x0=2;

[t,x] = ode45(@(t,x) A*x, 0:dt:T, x0);

plot(t, x(:,1));

i am getting error as

Error in ode45 (line 12)

[t,x] = ode45(@(t,x) A*x, 0:dt:T, x0);

i dont know what wrong i did here, if any body spoted out it will be very helful. Thank you.

Answer 1

[Star Strider]

The principal problem appears to be having 2 differential equations and 1 initial condition.

Try this —

w=2*pi;
zeta=0.25;
A=[0 1;-w^2 -zeta];
dt=0.01;
T=10;
x0=[0 2];                                           % Add Second Initial Condition
[t,x] = ode45(@(t,x) A*x, 0:dt:T, x0);

t = 1001×1

0 0.0100 0.0200 0.0300 0.0400 0.0500 0.0600 0.0700 0.0800 0.0900

x = 1001×2

0 2.0000 0.0200 1.9911 0.0398 1.9743 0.0594 1.9498 0.0788 1.9177 0.0978 1.8781 0.1163 1.8312 0.1344 1.7772 0.1518 1.7163 0.1687 1.6488

plot(t, x(:,1));

Make appropriate changes to get the desired result.

.

[Dinesh Durai]

Thank you

[Star Strider]

As always, my pleasure!