Why this code doesn't work?

6 次查看（过去 30 天）
Umut
Umut 2022-11-6
编辑： KSSV 2022-11-6
I am trying to get a velocity plot but the code doesn't work and I can't fix it.
ti=0.0; tf=15.0; ui=30.0;
m=2585; g=10; W=m*g; Theta=0.0; Fx=-2000;
f=0.03; rho=1.225; Cd=0.2; A=2.9; uw=0.0;
tol=1.0E-4; trace=1;
[t,u]= ode23("asdfg",ti,tf,ui,tol,trace);
plot(t,u,"r")
title("Vehicle Forward Speed");
xlabel("Time(sec)")
ylabel("u(m/sec)"); grid;
function udot = asdfg(t,u)
if u>0
udot=(1/m)*(Fx-W*sin(Theta)-f*W*cos(Theta)-0.5*rho*Cd*A*(u+uw)^2);
else
udot=0;
end
end
This was the last code I tried and I got this error message:
Error using odearguments
The last entry in tspan must be different from the first entry.
Error in ode23 (line 106)
odearguments(odeIsFuncHandle, odeTreatAsMFile, solver_name, ode, tspan, y0, options, varargin);
Error in untitled (line 5)
[t,u]= ode23("asdfg",ti,tf,ui,tol,trace);

请先登录，再回答此问题。

采纳的回答

Torsten
Torsten 2022-11-6
Ran in:
ti=0.0; tf=15.0; ui=30.0;
m=2585; g=10; W=m*g; Theta=0.0; Fx=-2000;
f=0.03; rho=1.225; Cd=0.2; A=2.9; uw=0.0;
tol=1.0E-4; trace=1;
options = odeset('RelTol',tol,'AbsTol',tol);
[t,u]= ode23(@(t,u)asdfg(t,u,m,Fx,W,Theta,f,rho,Cd,A,uw),[ti,tf],ui,options);
plot(t,u,"r")
title("Vehicle Forward Speed");
xlabel("Time(sec)")
ylabel("u(m/sec)"); grid;
function udot = asdfg(t,u,m,Fx,W,Theta,f,rho,Cd,A,uw)
if u>0
udot=(1/m)*(Fx-W*sin(Theta)-f*W*cos(Theta)-0.5*rho*Cd*A*(u+uw)^2);
else
udot=0;
end
end

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 General Applications 的更多信息

标签

产品


版本

R2022b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by