Don't understand the reason this code is giving me errors.

3 次查看（过去 30 天）
DJ V
DJ V 2024-8-22
评论： Voss 2024-8-22
The code that is producing the error is below. It says:
>> test
Error: File: test.m Line: 32 Column: 58
Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters.
>> test
Error: File: test.m Line: 30 Column: 60
Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters.
Code that produces errors is below.
clc;
mass = 13.5;
Jx = 0.8244;
Jy = 1.135;
Jz = 1.759;
Jxz = 0.1204;
G = Jx*Jz-Jxz^2;
G1 = Jxz*(Jx - Jy + Jz)/G;
G2 = (Jz*(Jz-Jy)+Jxz^2)/G;
G3 = Jz/G;
G4 = Jxz/G;
G5 = (Jz-Jx)/Jy;
G6 = Jxz/Jy;
G7 = ((Jx-Jy)*Jx +Jxz^2)/G;
G8 = (Jx/G);
p = 0;
q = 0;
r = 0;
l = 0.0000;
m = 0.0000;
n = 0.0000;
tspan = [0 10];
%[t,q] = ode45(@(t,q) (G5*p*r-G6*(p^2-r^2)+m/Jy), tspan,0);
%plot(t,q);
%pdot = (G1*p*q-G2*q*r + G3*l+G4*n);
[t,p]=ode45(@(t,p) (G1*p*q-G2*q*r+G3*l+G4*n),[0 10], 0.1);
plot(t,p,'--r');
disp(p);
disp(t);
[t,q] = ode45(@(t,r) (G5*p*r-G6*p*p-G6*r*r)+m/Jy), [0 10],0);
plot(t,q,'--g');
[t,r] = ode45(@(t,r) (G7*p*q-G1*q*r + G4*l+G8*n), [0 10],0);
plot(t,r,'--b')

请先登录，再回答此问题。

采纳的回答

Voss
Voss 2024-8-22
You have an extra ")" here:
[t,q] = ode45(@(t,r) (G5*p*r-G6*p*p-G6*r*r)+m/Jy), [0 10],0);
% ^ extra parenthesis
That parenthesis closes the ode45 function call, leaving the rest of the line ", [0 10],0);" hanging out with nothing to do, and the closing parenthesis in that part causes the syntax error.
  2 个评论
DJ V
DJ V 2024-8-22
Now it gives me the following error:
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0.1000
0
0.2500
0.5000
0.7500
1.0000
1.2500
1.5000
1.7500
2.0000
2.2500
2.5000
2.7500
3.0000
3.2500
3.5000
3.7500
4.0000
4.2500
4.5000
4.7500
5.0000
5.2500
5.5000
5.7500
6.0000
6.2500
6.5000
6.7500
7.0000
7.2500
7.5000
7.7500
8.0000
8.2500
8.5000
8.7500
9.0000
9.2500
9.5000
9.7500
10.0000
Error using *
Incorrect dimensions for matrix multiplication. Check that the number of columns in the first matrix matches the number of rows in the second matrix. To
perform elementwise multiplication, use '.*'.
Error in test>@(t,r)(G5*p*r-G6*p*p-G6*r*r+m/Jy) (line 30)
[t,q] = ode45(@(t,r) (G5*p*r - G6*p*p - G6*r*r + m/Jy), [0 10],0);
Error in odearguments (line 90)
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 test (line 30)
[t,q] = ode45(@(t,r) (G5*p*r - G6*p*p - G6*r*r + m/Jy), [0 10],0);
Voss
Voss 2024-8-22
If the original question is solved, please "Accept" this answer. Thanks!
Feel free to post a new question about error(s) you get running ode45.

请先登录，再进行评论。

更多回答（0 个）

类别

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

标签

产品


版本

R2019b

Community Treasure Hunt

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

Start Hunting!

Translated by