Recursive modeling in Simulink

8 次查看（过去 30 天）
Yannick Ongena
Yannick Ongena 2024-3-18
评论： Yannick Ongena 2024-3-24
I am learning Simulink. I've done around 50% of the onramp course so I tried modeling something on my own.
One of the reasons I wanted to learn simulink is to model population models so that's what I started with. The problem is, however that it's a recursive model and I don't know how to make this work in simulink...
The below is what I tried:
  5 个评论
显示 3更早的评论
Yannick Ongena
Yannick Ongena 2024-3-18
I just figured it out. I looked at the different blocks in the library under the discrete section and the memory block was exactly what I needed. As shown in my answer below, little changes are required to my currrent model to make it work as expected.
Yannick Ongena
Yannick Ongena 2024-3-24
just a follow-up... The onramp actually covers this technique using the unit step block. It was exactly what I needed to model this approach.
So for anybody in the future, just follow the onramp and you will understand

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Sam Chak
Sam Chak 2024-3-18
Hi @Yannick Ongena
If the population model can be represented as a discrete state-space system, then the appropriate approach would be to utilize the Discrete State-Space block.
  3 个评论
显示 1更早的评论
Sam Chak
Sam Chak 2024-3-18
Hi @Yannick Ongena
If you found the suggestion regarding the Discrete State-Space block and the rounding issue helpful, please consider clicking 'Accept' ✔️ on the answer. Do you primarily deal with discrete systems?
Yannick Ongena
Yannick Ongena 2024-3-19
I'm not really primarily dealing with discrete systems... A few months ago I started with a pre-master environmental science and topics like this raised my interest so I bought a few books and wanted to play with these concepts. Next year, I will have a class focussed on simulating population and the effect of humans on population. Meanwhile I still have to brush up on a lot of the math concepts. But things like mathematical modeling and simulation is definitly something that raised my interest a lot.

请先登录，再进行评论。

更多回答（1 个）

Yannick Ongena
Yannick Ongena 2024-3-18
I browsed through the discrete section in the library and played a bit with the memory component. This seemed to do the trick.
The starting population is now the initial condition of the memory block. The rest is somewhat identical except the order in which they are in the model.
  2 个评论
Sam Chak
Sam Chak 2024-3-18
Hi @Yannick Ongena
By the way, is your population model continuous or discrete? For instance, if the current population count is 34, it wouldn't make sense to have 3.4 births (where 0.4 represents half-alive individuals) or 6.8 deaths (where 0.8 indicates individuals on the brink of death), correct?
Yannick Ongena
Yannick Ongena 2024-3-18
编辑：Yannick Ongena 2024-3-18
Good point. I would need to do some rounding to make it more accurate.
The model is discrete. The time steps represent a year.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Model, Block, and Port Callbacks 的更多信息

标签

产品


版本

R2023b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by