How to use ode45 for a row vector

function v = f(t,x);
zeta=0.9
m=5; k=1000;
c=2.*zeta.*sqrt(m*k); 
v=[x(2); x(1).*-k/m+x(2).*-c./m];
end

and

clear all
xo=[0.05; 0];
ts=[0 3];
[t,x]=ode45('f',ts,xo);
figure(1)
plot(t,x(:,1))

I was wondering how I can make this plot work with multiple zeta values

zeta=[0, 0.1, 0.25, 0.5, 0.75, 0.9, 1];

Answer 1

[madhan ravi]

Parametrization and loop through zeta.

[Erik Sharrer]

how would i go about the loop?

clear all
xo=[0.05; 0];
ts=[0 3];
[t,x]=ode45(@myfun,ts,xo);
figure(1)
plot(t,x(:,1))


function v = myfun(t,x);
zeta=0.9
m=5; k=1000;
c=2.*zeta.*sqrt(m*k); 
v=[x(2); x(1).*-k/m+x(2).*-c./m];
end

would it be before the function and contain whats in the first block of code?

[madhan ravi]

xo=[0.05; 0];
ts=[0 3];
zeta = ... values;
na = sprintfc('zeta=%.2f',zeta); % use compose() in later versions
for zeta = zeta
[t,x]=ode45(@(t,x)myfun(t,x,zeta),ts,xo);
plot(t,x(:,1))
hold on
end

function v = myfun(t,x,zeta)
m=5; k=1000;
c=2.*zeta.*sqrt(m*k); 
v=[x(2); x(1).*-k/m+x(2).*-c./m];
end

[Erik Sharrer]

what does 'zeta=%.2f' mean?

Answer 2

[Steven Lord]

See the "Pass Extra Parameters to ODE Function" example on the documentation page for the ode45 function. You can use it as a model for your code.

[Erik Sharrer]

I still would need to use a loop though right?