Search found 283 matches

by marek [BayesFusion]
Tue Dec 04, 2018 9:17 pm
Forum: GeNIe
Topic: Any advice on modelling a variable with combined prohibiting and promoting effects?
Replies: 13
Views: 4851

Re: Any advice on modelling a variable with combined prohibiting and promoting effects?

There are two other papers that you may find useful in obtaining insight into the Noisy-OR/Noisy-MAX gates: (1) The original paper by Max Henrion, where he introduces the Noisy-OR gate: Henrion, Max (1989). Some practical issues in constructing belief networks. Kanal, L.N., Levitt, T.S. & Lemmer, J....
by marek [BayesFusion]
Sat Dec 01, 2018 4:26 am
Forum: GeNIe
Topic: Any advice on modelling a variable with combined prohibiting and promoting effects?
Replies: 13
Views: 4851

Re: Any advice on modelling a variable with combined prohibiting and promoting effects?

Anyway I still don't understand why a dedicated distinguished state and the constraining of it is necessary. Noisy-MAX nodes need to have a distinguished state. A good starting point for understanding this is a technical report by Javier Diez and myself, available at http://www.ia.uned.es/~fjdiez/p...
by marek [BayesFusion]
Sat Dec 01, 2018 4:19 am
Forum: GeNIe
Topic: Strength of Influence
Replies: 3
Views: 2521

Re: Strength of Influence

There is currently no easy way but the upcoming release of GeNIe 2.3 will have a dialog with a complete list of arcs along with their strengths. We are considering a functionality that will allow to copy the strengths (text format) to an editor or an Excel spreadsheet. Please stay tuned.

Marek
by marek [BayesFusion]
Sat Dec 01, 2018 4:12 am
Forum: GeNIe
Topic: Is the clustering algorithm eqivalent to the HUGIN junction tree?
Replies: 3
Views: 2608

Re: Is the clustering algorithm eqivalent to the HUGIN junction tree?

SMILE's clustering algorithm is a variation on Lauritzen-Spiegelhalter's junction tree algorithm. It is a variation and, as you may have noticed, it is very very fast. It is a result of combining good ideas with good engineering.
Cheers,

Marek
by marek [BayesFusion]
Sat Dec 01, 2018 4:09 am
Forum: GeNIe
Topic: About Parameter Learning
Replies: 1
Views: 1849

Re: About Parameter Learning

The EM algorithm replaces all missing values by the most likely values given the values of all the other variables and the current model and then learns the network parameters using MLE. It repeats this process until the change between the values of the parameters between two subsequent runs is smal...
by marek [BayesFusion]
Tue Nov 20, 2018 4:51 pm
Forum: SMILE
Topic: Set node state as evidence
Replies: 3
Views: 2613

Re: Set node state as evidence

I'm not sure if I fully understand what you are doing but it seems that you are trying to replicate the formalism of Dynamic Bayesian Networks :-). I understand that you are using only first order influences. Please note that with GeNIe/SMILE you can have any time-order influences. Coming back to yo...
by marek [BayesFusion]
Tue Nov 20, 2018 12:49 pm
Forum: GeNIe
Topic: Any advice on modelling a variable with combined prohibiting and promoting effects?
Replies: 13
Views: 4851

Re: Any advice on modelling a variable with combined prohibiting and promoting effects?

Agreed here -- when building an AND/MIN interaction by means of an OR/MAX gate, the distinguished states are a complete fiction, just to allow for the negations. In reality, there is one distinguished state and it is the one that has no influence. Please look at the model that I have attached to my ...
by marek [BayesFusion]
Tue Nov 20, 2018 3:07 am
Forum: GeNIe
Topic: Any advice on modelling a variable with combined prohibiting and promoting effects?
Replies: 13
Views: 4851

Re: Any advice on modelling a variable with combined prohibiting and promoting effects?

I have to confess that I get confused here myself and have to always think hard before creating a Noisy-AND/MIN node. This means that our idea years ago to implement just one type of node for both OR and AND interactions was not that great -- what is theoretically simple, may be hard for a human mod...
by marek [BayesFusion]
Mon Nov 19, 2018 4:40 pm
Forum: GeNIe
Topic: visualization and business vs academic version
Replies: 3
Views: 2618

Re: visualization and business vs academic version

Hi Lihi, We certainly prefer that you ask questions on the Forum -- this benefits all GeNIe users. Let me try to answer your questions: (1) I'm not sure what you mean by "professional looking visualizations." If you let us know about your needs, we will consider implementing them. Is the resolution ...
by marek [BayesFusion]
Sat Nov 17, 2018 2:10 am
Forum: GeNIe
Topic: Any advice on modelling a variable with combined prohibiting and promoting effects?
Replies: 13
Views: 4851

Re: Any advice on modelling a variable with combined prohibiting and promoting effects?

Thank you for your kind words. I just wanted to remark that the Noisy-Max gate in GeNIe allows you to create both OR and AND gates. To create an AND gate, just negate the parents (by changing the order of their states) and negate the child (by changing the order of its states). It is just a simple a...
by marek [BayesFusion]
Sat Nov 17, 2018 1:51 am
Forum: SMILE
Topic: Help with Bayesian Modeling
Replies: 6
Views: 3530

Re: Help with Bayesian Modeling

I don't see an easy way off-hand -- Marek
by marek [BayesFusion]
Tue Nov 13, 2018 2:05 pm
Forum: SMILE
Topic: Help with Bayesian Modeling
Replies: 6
Views: 3530

Re: Help with Bayesian Modeling

To start with, I recommend reading up on dynamic Bayesian networks (DBNs). There is a 2002 doctoral dissertation by Kevin Murphy (on the list of references in GeNIe manual) available electronically on the web. There is also an AI textbook by Russell & Norvig (also on the list of references in GeNIe ...
by marek [BayesFusion]
Wed Oct 31, 2018 12:02 pm
Forum: SMILE
Topic: Set node state as evidence
Replies: 3
Views: 2613

Re: Set node state as evidence

I'm not sure I fully understand your question. GeNIe and SMILE allow for virtual evidence, which is specifying evidence as a probability distribution. It should be quite intuitive at the GUI but please search the manual for "virtual evidence" in case you cannot figure it out. Is this what you want? ...
by marek [BayesFusion]
Fri Oct 05, 2018 2:52 pm
Forum: GeNIe
Topic: Just a small and humble suggestion
Replies: 2
Views: 2388

Re: Just a small and humble suggestion

I have to admit that over time I have grown to develop the same feeling about the Noisy-MAX gate as you did. Even though Noisy-MAX with negation allows for implementing Noisy-MIN, it would be better to have a separate entry point/GUI choice for Noisy-AND (and Noisy-MIN as a generalization to multipl...
by marek [BayesFusion]
Fri Oct 05, 2018 2:48 pm
Forum: GeNIe
Topic: Any advice on modelling a variable with combined prohibiting and promoting effects?
Replies: 13
Views: 4851

Re: Any advice on modelling a variable with combined prohibiting and promoting effects?

If you have only two parents and one child, why not entering the parameters of the conditional probability distributions manually? Going through this exercise will clarify the issues for you. Canonical gates are meant to save you time and lead to fewer parameters in the model through additional inde...