Logistic neuron

[Wild]

Hi, I found this in the doc: http://www.simbrain.net/Documentation/docs/Pages/Network/neuron/Logistic.html
 and later on found out that it exists in 2.0 version. I didn't find it in 3.0 . I tried to run 3.0 from source and it doesn't show up either.  
Is there any plans to add it and is it available via scripts somehow ?

[jyoshimi]

Hi there, sorry I did not notice this message earlier!   The version of logistic we had before was really an "activity generator", which used the logistic map to produce deterministic outputs, including chaotic ones depending on the value of a parameter r:

https://en.wikipedia.org/wiki/Logistic_function

However, in neural networks logistic usually refers to the logistic sigmoid

https://en.wikipedia.org/wiki/Logistic_function

That is currently available, as one of several options under discrete sigmoid.

We do plan to put the first one back as a type of "activity generator" soon (we just need to find time to implement activity generators!)

Let me know if you have further questions.

- Jeff

PS: If I don't respond here quickly, feel free to email me.  My email is easy to find online.

[Wild]

Jeff Yoshimi wrote

The version of logistic we had before was really an "activity generator", which used the logistic map to produce deterministic outputs, including chaotic ones depending on the value of a parameter r

That's exactly what I need.

We do plan to put the first one back as a type of "activity generator" soon (we just need to find time to implement activity generators!)

Can you suggest some software similar to simbrain where I can get it while you're working on it ?

Also you linked same wiki article 2 times , I assume you wanted to link this one :
https://en.wikipedia.org/wiki/Logistic_map

[jyoshimi]

Hi again.  Yes you are right about the repeated wiki article.  What I had in mind was the logistic map entry you linked to.

It's good to know someone wants this.  I think we can try to have this done within the next month. I just opened an issue on github (feel free to follow up there.  I don't knwo why I am not receiving email notifications from nabble).

https://github.com/simbrain/simbrain/issues/25

As for other software, nothing comes to mind that is really graphical.   I'd say matlab, octave, or python with numpy and scipy are your best bets but they all require scripting.

- Jeff

[Wild]

Thanks for your work on simbrain and  activity generators in particular even during holidays )

Happy new year !

[jyoshimi]

Hi again,

No problem!  What happened is that as I was implementing this, some things I want to improve in the code came up.   But those could slow me down quite a bit.   How urgent is this for you?  Maybe I should separate my code refactoring from the activity generator thing, so that the activity generators are available more quickly...

BTW this forum is ok, but issues on github are probably where some of this discussion should be happening... Feel free to open an issue there.

- Jeff

[Wild]

I wasn't trying to hurry you, just wanted to give thanks for your work.
Right now I'm using code from Jeff Heaton's book  ( modified and with a lot of bad code) that is somewhat working although I'm not entirely sure if it's working properly. Also considering I'm new to this, working in GUI helps a lot at learning and understanding what's happening inside.

[jyoshimi]

In case anyone's watching this, i do have logistic now running in a branch, which those who are super git savvy can see by cloning the repo, switching to the "activity_generator" branch, and compiling and running.  Activity generators like logistic (which don't use inputs) show up as "square" rather than round nodes in the network.  

However, what's slowing me down is that this prompted a massive refactor, as I already noted.   Just when it was coming along, I figured out a way to make it even better.  This is all happening behind the scenes: simbrain will look the same when it's all done, but it will be much, much easier to add new neuron and activity generator types.

[jyoshimi]

Just a note that this is now in the main repository on github.   If you know how to clone repository you can see the activity generators and logistic in particular.   Let me know if questions, and ping me by email if I don't respond here.

- Jeff

[jyoshimi]

Ok it's finally in the main release!

http://simbrain.net/Downloads/downloads_main.html