solving a differential equation coupling together in matrix and vector form with ode45
1 次查看(过去 30 天)
显示 更早的评论
I have two problem:
1) I used two functions for solving a set of equation not in matrix or vector form but like
[x(2);3+x(4)+x(3);x(4);....................]
then [t,x] = ode45(@(t,x) lili(t,x),tspan,x0);
now I need the vector of dx=[x(2) x(4) x(6)]
but it doesnt return this vector.
2) i want to solve equation like this D2y=d2x+cross(m,n)
its clear cross product is in vector form
how could i solve matrix form of differential equation?
especially initial values is a vector
1 个评论
Torsten
2018-12-6
1) Unclear what you have done and what your problem is. Please provide the code you are using and possibly the error message you get.
2) ODE45 expects the differential equations to be given in vector format. So convert your equations from matrix form to vector form.
Best wishes
Torsten.
采纳的回答
roya afshar
2018-12-7
2 个评论
Torsten
2018-12-7
You solve
x1'' = x1
x2'' = x2 + 1
x3'' = x3 + 2
with initial conditions
x1(0)=1, x2(0)=8, x3(0)=9, x1'(0)=2, x2'(0)=3, x3'(0)=4
and plot x1, x2 and x3 in plot 1 and x1', x2' and x3' in plot 2.
Is it that what you wanted to achieve ?
更多回答(1 个)
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Ordinary Differential Equations 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!