How to use the ode15i function in this code?

syms x(t)

m = 60;

k = 1;

F = 100;

fs = 0;

vmax = 10;

[K,E] = ellipke((x / pi-floor(x/pi))*pi);

s = sqrt(2) * E + ( 2 * ellipke(1/2) * floor(x / pi));

r = abs(((cos(x))^2+1)^1.5/sin(x))

Ds = diff(s, t)

D2s = diff(s, t, 2)

dnjstlafur = 0.5 * (((m * Ds^2) / r)) + abs(((m * Ds^2) / r - fs) - fs);

ode = m * D2s == sqrt(F^2 - dnjstlafur^2)

[V] = odeToVectorField(ode)

M = matlabFunction(V, 'vars', {'t', 'Y'});

[t, Y]= ode45(M,[0, 4],[0, 0]);

plot(t, V(:,2));

This is error message.

다음 사용 중 오류가 발생함: mupadengine/feval_internal

Invalid argument.

오류 발생: odeToVectorField>mupadOdeToVectorField (171번 라인)

T = feval_internal(symengine,'symobj::odeToVectorField',sys,x,stringInput);

오류 발생: odeToVectorField (119번 라인)

sol = mupadOdeToVectorField(varargin);

오류 발생: untitled (14번 라인)

[V] = odeToVectorField(ode)

I know I should use ode15i fuction, but I don't know how to use that function. Can anyone write the code for me?

Answer 1

[Umang Pandey]

Hi,

The error you are facing is due to the use of "odeToVectorField" function. The function can convert only quasi-linear differential equations. You can refer the following documentation for more information:

https://www.mathworks.com/help/symbolic/odetovectorfield.html#bvlqf2q-6

Please refer to the following documentation for implementation details and examples on using "ode15i" function:

https://www.mathworks.com/help/matlab/ref/ode15i.html

Best,

Umang