How to give ode45 just 1 time step?

Question

Saiprasad Gore 2017-5-5

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/338833-how-to-give-ode45-just-1-time-step

评论： Steven Lord 2021-4-20

If I give only one step by tspan = 0:0.01:0.01; then it takes many smaller steps automatically between 0 and 0.01 How can I force it to take just one step?

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Jan 2017-5-5

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/338833-how-to-give-ode45-just-1-time-step#answer_265738

ODE45 is an integrator with a step size control, which adjust the steps to satisfy the demands for accuracy. This helps to find the optimum between rounding and discretization errors. In consequence you can and should not force the integrator to use a specific step size.

Use a fixed step size integrator if you have any good reason to do so, but not ODE45.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Riyadh BELBECIR 2021-4-20

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/338833-how-to-give-ode45-just-1-time-step#answer_679377

The smallest value can be taken is two steps

Example :

tspan = [0 1 2];

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Steven Lord 2021-4-20

The values you specify as the tspan input to an ODE solver do not affect the steps the solver takes internally. If you specify more than 2 elements in tspan they specify the points at which the ODE solver returns the solution.

请先登录，再进行评论。