differential equations solution doesnt work
Mostrar comentarios más antiguos
i have for example
syms x y(x)
M4=(R1*x-p*g*pi*0.0810*(x-l1/2)-0.2626*p*g*pi*(x-K1-l2/2)-0.0630*p*g*pi*(x-K2-l3/2)-p*g*pi*((5*x - 19)*(3025*x^2 - 49225*x + 219217))/4704000)/E4/(pi*(b*x+c)^4/64);
%with all the variables known
and i type
ode = diff(y,x,2) == M4;
conds = [y(K4)== 1.7536e-04 Dy(K4)== -2.6143e-04];
ySol(x) = dsolve(ode,conds);
ySol = vpa(simplify(ySol))*10^(6)
yesterday i could solve the equation but today i try it and it continuous running without stopping
Also when i int M4 the result is different from the result yesterday this one does not have and log in it or fantastic number
how can i fix this?
6 comentarios
darova
el 21 de Nov. de 2019
Did you try to solve it numerically?
Walter Roberson
el 21 de Nov. de 2019
Please post values for all of the constants.
To verify: Dy is diff(y) ?
Dimitrios Adam
el 22 de Nov. de 2019
Editada: Walter Roberson
el 22 de Nov. de 2019
Walter Roberson
el 22 de Nov. de 2019
Please post values for all of the constants.
When you do that assignment to I, are you using I/E4/(pi*(b*x+c)^4/64) in place of the M4 you defined before?
Dimitrios Adam
el 23 de Nov. de 2019
Editada: Walter Roberson
el 23 de Nov. de 2019
Walter Roberson
el 23 de Nov. de 2019
The expression
I=vpa((R1*x-p*g*pi*0.0810*(x-l1/2)-0.2626*p*g*pi*(x-K1-l2/2)-0.0630*p*g*pi*(x-K2-l3/2)-p*g*pi*((5*x - 19)*(3025*x^2 - 49225*x + 219217));
is missing two ) somewhere. As we are not familiar with the underlying equations, we will have to get you to make the repair.
Respuestas (0)
Categorías
Más información sobre Mathematics en Centro de ayuda y File Exchange.
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!