why does ode45 happen this index error?
2 次查看(过去 30 天)
显示 更早的评论
I've been struggling with this program for a long time.
Is this ode45 being used incorrectly?
global d;
d=1;
tspan=[0;0.05];
xi=[1;2;pi];
vk=[3;5];
func=@(xi,vk) TwoWheel2(xi,vk);
[t,y]=ode45(func,tspan,0);
function dxi = TwoWheel2(xi,vk)
v1=speed(vk);
wk=toRadian(vk);
dxi = zeros(3,1);
dxi(1) = cos(xi(3)) * v1;
dxi(2) = sin(xi(3)) * v1;
dxi(3) = wk;
end
function u0=toRadian(vk)
global d;
vr=vk(1);
vl=vk(2);
u0=(vr-vl)/(2*d);
end
function v1=speed(vk)
vr=vk(1);
vl=vk(2);
v1=(vr+vl)/2;
end
>> testode
The index exceeds the number of array elements (1).
error: testode>speed (line 22)
vl=vk(2);
error: testode>TwoWheel2 (line 7)
v1=speed(vk);
error: testode>@(xi,vk)TwoWheel2(xi,vk) (line 4)
func=@(xi,vk) TwoWheel2(xi,vk);
error: odearguments (line 90)
f0 = feval(ode,t0,y0,args{:}); % ODE15I sets args{1} to yp0.
error: ode45 (line 115)
odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);
error: testode (line 5)
[t,y]=ode45(func,tspan,0);
0 个评论
采纳的回答
Alan Stevens
2020-9-19
See the following:
global d;
d=1;
tspan=[0;0.05];
xi=[1;2;pi];
vk=[3;5];
[t,y]=ode45(@TwoWheel2,tspan,xi,[],vk);
function dxi = TwoWheel2(~,xi,vk)
v1=speed(vk);
wk=toRadian(vk);
dxi = zeros(3,1);
dxi(1) = cos(xi(3)) * v1;
dxi(2) = sin(xi(3)) * v1;
dxi(3) = wk;
end
function u0=toRadian(vk)
global d;
vr=vk(1);
vl=vk(2);
u0=(vr-vl)/(2*d);
end
function v1=speed(vk)
vr=vk(1);
vl=vk(2);
v1=(vr+vl)/2;
end
5 个评论
Alan Stevens
2020-9-19
编辑:Alan Stevens
2020-9-19
- Yes, [] is a placeholder for options.
- You would often have t, the time value there (more generally, the name of the independent variable); but, in your case, t is not used explicitly within TwoWheel2, so MATLAB suggests replacing it by ~. If it did make explicit use of the value of t, then ~ would need to be replaced by t. The ~ isn't essential; the routine would still work if you did replace it with t.
更多回答(0 个)
另请参阅
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!