Representing and approximating third order differential equations
3 次查看(过去 30 天)
显示 更早的评论
I am trying to approximate a differential equation in terms of two vectors, x any y and also return a value of a solution. My differential equation is hard to represent though:
d3y/dx3 + dy/dx - xy + d2y/dx2 = 2 xE[1, 5]
initial conditions y(0), dy/dx(0) and d2y/dx2(0) have been given.
Any suggestions?
回答(1 个)
Francisco Angel
2014-4-3
编辑:Francisco Angel
2014-4-3
Transform the problem in a system of first order differential equations:
dy1 / dx = y2 dy2 / dx = y3 dy3 / dx = 2-y3-x*y1-y2
with initial conditions y1(0) y2(0) and y3(0) then solve it using ode45 for example:
if true
% code
[t,Y]=ode45(@system,[1 5],[y1(0) y2(0) y3(0)]);
function dy=system(X,Y)
dy(1)=Y(2);
dy(2)=Y(3);
dy(3)=2-Y(3)-X*Y(1)-Y(2);
dy=dy';
end
end
In doubt check formatting issues tipyng help ode45 in command line.
0 个评论
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!