Ode45 extra parameters
4 views (last 30 days)
Show older comments
SilverSurfer
on 19 Mar 2016
Commented: Star Strider
on 22 Mar 2016
I would like to solve some equations with ode45.
The function is this:
function [ y_punto ] = bicicletta(t,y,a,b,u,delta,Ca,Cp,Iz,Fd)
v = y(1);
r = y(2);
alfaa = atan((v+a*r)/u)-delta;
alfap = atan((v-b*r)/u);
Fya = -Ca*alfaa;
Fyp = -Cp*alfap;
if (t>=tdon && t<=tdoff)
Fyad=Fd;
else
Fyad=0;
end
v_punto = 1/m*(Fya*cos(delta)+Fyp+Fyad)-ru;
r_punto = 1/Iz*(Fya*cos(delta)*a+Fyad*a-Fyp*b);
y_punto = [v_punto;r_punto];
end
Here is the script for starting simulation
clc
clear
a = 0.78;
b = 0.83;
Ca = 27537.5;
Cp = 27537.5;
Iz = 408.9;
u = 15*1000/3600;
delta = 5 * pi/180;
Fd = 100;
tf=5;
tspan = [0 tf];
y0 = [0;0];
[t,y] = ode45(bicicletta,tspan,y0);
The fact is that I need to pass extra parameters to the function. I don't know if I can define the function in this way
function [ y_punto ] = bicicletta(y)
and pass other parameters in another way for example declaring as global.
I did some search and I found this way of using ode45 but it gives me error
[t,y] = ode45(@(t,y)bicicletta(t,y,a,b,u,delta,Ca,Cp,Iz),tspan,y0);
2 Comments
Stephen23
on 19 Mar 2016
Edited: Stephen23
on 19 Mar 2016
Your last line of code, where you create an anonymous function:
ode45(@(t,y)bicicletta(t,y,a,b,u,delta,Ca,Cp,Iz),tspan,y0);
is the correct approach to passing extra arguments. Please show us the complete error message (this means all of the red text).
Do not use globals: this is a slow and buggy way to write code.
Stephen23
on 21 Mar 2016
Edited: Stephen23
on 21 Mar 2016
Here his the error
Error in odearguments (line 87)
f0 = feval(ode,t0,y0,args{:}); % ODE15I sets args{1} to yp0.
Error in ode45 (line 115)
odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);
Error in simulazione (line 18)
[t,y] = ode45(@(t,y)bicicletta(t,y,a,b,u,delta,Ca,Cp,Iz),tspan,y0);
I attached also the scripts
Accepted Answer
Star Strider
on 19 Mar 2016
You have to define ‘tdon’ and ‘tdoff’ in your ‘bicicletta’ ODE function. I have no idea what you want to do, so I cannot correct that for you.
6 Comments
More Answers (0)
See Also
Categories
Find more on Ordinary Differential Equations in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!