Not enough input arguments ode45

Question

Aleyna 2023-11-22

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2050827-not-enough-input-arguments-ode45

编辑： Sulaymon Eshkabilov 2023-11-22

function dy = rigid(t,y)
% a column vector
dy = zeros(3,1);    
w1=sin(t)*exp(-t);
w2=sin(2*t)*exp(-2*t);
w3=sin(3*t)*exp(-3*t);
dy(1) =(1/cos(y(2)))* (cos(y(3))*w1-sin(y(3))*w2);
dy(2) =(sin(y(3))*w1+cos(y(3))*w2);
dy(3) =w3+(1/cos(y(2)))*(-w1*cos(y(3))*sin(y(2))+w2*sin(y(2))*sin(y(3)));
syms a b c ad bd cd om1 om2 om3 t real
%rotations for 1(a)-2(b)-3(c)
X=[1 0 0;0 cos(a) sin(a);0 -sin(a) cos(a)];
Y=[cos(b) 0 -sin(b);0 1 0;sin(b) 0 cos(b)];
Z=[cos(c) sin(c) 0;-sin(c) cos(c) 0;0 0 1];
%Last rotation 3(c)
L=Z
%Last 3(c) and middle rotation 2(b)
LM=Z*Y
%Last rotation angle derivative
dv1=[0; 0; cd]
%Middle rotation angle derivative
dv2=[0; bd; 0]
%First rotation angle derivative
dv3=[ad; 0; 0]
w11=dv1;
w22=L*dv2;
w33=LM*dv3;
%summation
w=w11+w22+w33
[S] = equationsToMatrix([w], [ad, bd, cd])
%Convert to differential equation form
%kinematic equation
IS=simplify (inv(S))
%Calculate differential equations
%angular velocity vectors
om1=sin(t)*exp(-t);
om2=sin(2*t)*exp(-2*t);
om3=sin(3*t)*exp(-3*t);
%Differential equation
angd=IS*[om1 om2 om3]'
options = odeset('RelTol',1e-4,'AbsTol',[1e-4 1e-4 1e-5]);
[T,Y] = ode45(@rigid,[0 2],[0 0 0],options);
plot(T,Y(:,1),'*',T,Y(:,2),'.',T,Y(:,3),'+')
legend('a','b','c')

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Aleyna 2023-11-22

Question: Calculate Euler angles differential equations for 1(a)-2(b)-3(c) rotation sequence

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Answer 1

Dyuman Joshi 2023-11-22

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https://ww2.mathworks.cn/matlabcentral/answers/2050827-not-enough-input-arguments-ode45#answer_1358042

在 MATLAB Online 中打开

I am not sure how the different symbolic variables and expressions come into play here for solving the ODE.

Nonetheless, Any functions defined in a script must be at the end of the script.

Also, the call to the ODE solver (ode45 in this case) should be outside the ODE funciton.

syms a b c ad bd cd om1 om2 om3 t real

%rotations for 1(a)-2(b)-3(c)

X=[1 0 0;0 cos(a) sin(a);0 -sin(a) cos(a)];

Y=[cos(b) 0 -sin(b);0 1 0;sin(b) 0 cos(b)];

Z=[cos(c) sin(c) 0;-sin(c) cos(c) 0;0 0 1];

%Last rotation 3(c)

L=Z;

%Last 3(c) and middle rotation 2(b)

LM=Z*Y;

%Last rotation angle derivative

dv1=[0; 0; cd];

%Middle rotation angle derivative

dv2=[0; bd; 0];

%First rotation angle derivative

dv3=[ad; 0; 0];

w11=dv1;

w22=L*dv2;

w33=LM*dv3;

%summation

w=w11+w22+w33;

[S] = equationsToMatrix([w], [ad, bd, cd]);

%Convert to differential equation form

%kinematic equation

IS=simplify (inv(S));

%Calculate differential equations

%angular velocity vectors

om1=sin(t)*exp(-t);

om2=sin(2*t)*exp(-2*t);

om3=sin(3*t)*exp(-3*t);

%Differential equation

angd=IS*[om1 om2 om3]';

%% Call to ODE

options = odeset('RelTol',1e-4,'AbsTol',[1e-4 1e-4 1e-5]);

[T,Y] = ode45(@rigid,[0 2],[0 0 0],options);

%% Plotting the ODE

plot(T,Y(:,1),'*',T,Y(:,2),'.',T,Y(:,3),'+')

legend('a','b','c')

%% Move the ODE function to the bottom/end of the script

function dy = rigid(t,y)

% a column vector

dy = zeros(3,1);

w1=sin(t)*exp(-t);

w2=sin(2*t)*exp(-2*t);

w3=sin(3*t)*exp(-3*t);

dy(1) =(1/cos(y(2)))* (cos(y(3))*w1-sin(y(3))*w2);

dy(2) =(sin(y(3))*w1+cos(y(3))*w2);

dy(3) =w3+(1/cos(y(2)))*(-w1*cos(y(3))*sin(y(2))+w2*sin(y(2))*sin(y(3)));

end

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Answer 2

Sulaymon Eshkabilov 2023-11-22

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2050827-not-enough-input-arguments-ode45#answer_1358047

编辑：Sulaymon Eshkabilov 2023-11-22

在 MATLAB Online 中打开

Don't use the MATLAB's built in function names as a variable name - cd. Why to display all iterations that can be also skipped with ";". Here is the corrected code:

options = odeset('RelTol',1e-4,'AbsTol',[1e-4 1e-4 1e-5]);

[T,Y] = ode45(@rigid,[0 2],[0 0 0],options);

angd =