It looks like you're new here. If you want to get involved, click one of these buttons!

- All Categories 2.4K
- Chat 505
- Study Groups 21
- Petri Nets 9
- Epidemiology 4
- Leaf Modeling 2
- Review Sections 9
- MIT 2020: Programming with Categories 51
- MIT 2020: Lectures 20
- MIT 2020: Exercises 25
- Baez ACT 2019: Online Course 339
- Baez ACT 2019: Lectures 79
- Baez ACT 2019: Exercises 149
- Baez ACT 2019: Chat 50
- UCR ACT Seminar 4
- General 75
- Azimuth Code Project 111
- Statistical methods 4
- Drafts 10
- Math Syntax Demos 15
- Wiki - Latest Changes 3
- Strategy 113
- Azimuth Project 1.1K
- - Spam 1
- News and Information 148
- Azimuth Blog 149
- - Conventions and Policies 21
- - Questions 43
- Azimuth Wiki 719

Options

I made a new article about delayed feedback, since I introduced the concept in the logistic equation article. It's related to stochastic delay differential equation but as always I think it's good to separate the qualitative features that don't come from stochasticity. In this case, the fact that if you add delay to your favourite ODE you probably break its (in)stability properties in some regimes. Which then means that the equation amplifies noise and therefore both numerical approximations and stochastically driven versions are likely to be problematic.

The article is still half-cooked.

## Comments

I have now expanded the article with a short analytical discussion of instability of a particular delayed-feedback system:

$$ \dot x(t) = - x(t-\Delta) $$ and some observations about the implications for numerical stability and the noise-driven version.

Comments solicited.

To reassure myself about the claims I have been doing some numerical experiments with R which I should probably add to the wiki in the vein of Staffan Liljegren's Experiments in predator-prey in Sage.

`I have now expanded the article with a short analytical discussion of instability of a particular delayed-feedback system: $$ \dot x(t) = - x(t-\Delta) $$ and some observations about the implications for numerical stability and the noise-driven version. Comments solicited. To reassure myself about the claims I have been doing some numerical experiments with R which I should probably add to the wiki in the vein of Staffan Liljegren's [Experiments in predator-prey in Sage](http://www.azimuthproject.org/azimuth/show/Experiments+in+predator-prey+in+Sage).`

GREAT!

I really want to write about the delayed action oscillator and El Niño in This Week's Finds. When I do it, I'll take advantage of all the stuff we have on the Azimuth Wiki, credit everyone who helped, and link to it.

Yes, please add your R code to Delayed feedback, just as Graham did in Quantitative ecology.

By the way: we follow the Wikipedia conventions on capitalizing page titles. So, I changed the title of your page from delayed feedback to Delayed feedback. This process creates a redirect so that now both links work.

I also added

`category: mathematical methods`

to the bottom of your page. This makes it easier for the lab elves to add a link, and someday a description, to the page Methodology.

I'm so happy you've joined our team!

`GREAT! <img src = "http://math.ucr.edu/home/baez/emoticons/thumbsup.gif" alt = ""/> I really want to write about the delayed action oscillator and El Niño in This Week's Finds. When I do it, I'll take advantage of all the stuff we have on the Azimuth Wiki, credit everyone who helped, and link to it. Yes, please add your R code to [[Delayed feedback]], just as Graham did in [[Quantitative ecology]]. By the way: we follow the Wikipedia conventions on capitalizing page titles. So, I changed the title of your page from [[delayed feedback]] to [[Delayed feedback]]. This process creates a redirect so that now both links work. I also added `category: mathematical methods` to the bottom of your page. This makes it easier for the lab elves to add a link, and someday a description, to the page [[Methodology]]. I'm so happy you've joined our team!`

Now done...

`Now done...`