Search found 303 matches

by marek [BayesFusion]
Mon Oct 26, 2020 2:58 pm
Forum: GeNIe
Topic: Two equations for one node
Replies: 2
Views: 10

Re: Two equations for one node

Sure, this is possible, although you would need two separate nodes (this is closer to what your problem really is, I believe). Please look at the model in our model repository (should be also included among the example models on your disk) called "Heat Equations Autodiscretized Hybrid.xdsl". The nod...
by marek [BayesFusion]
Sun Oct 25, 2020 5:30 pm
Forum: GeNIe
Topic: Model Comparison through log(p)
Replies: 4
Views: 38

Re: Model Comparison through log(p)

Not at all. log(p) is the probability of the whole data set given the model and it depends strongly on the data set size and the number of variables. Generally, the probability of a combination of values of nodes within a record is very low. Please verify this by choosing a record in your data set, ...
by marek [BayesFusion]
Sun Oct 25, 2020 11:03 am
Forum: GeNIe
Topic: Dynamic Bayesian Network (DBN) for time series
Replies: 8
Views: 41

Re: Dynamic Bayesian Network (DBN) for time series

Here are two models that you may want to explore. The "Foxes Rabbits Equations.xdsl" model is a hybrid model that contains the difference equations describing the dynamic model. I used this model to derive the CPTs for the Dynamic Bayesian Network in "Foxes Rabbits DBN 20.xdsl". I discretized the co...
by marek [BayesFusion]
Sun Oct 25, 2020 10:36 am
Forum: GeNIe
Topic: Cross validation in GeNIe with different proportions
Replies: 1
Views: 6

Re: Cross validation in GeNIe with different proportions

Sure but you have to split the file into the two parts (70% and 30%) yourself. Then learn the model from the 70% part and perform "Test only" on the 30%. k-fold cross-validation and leave-one-out are much more efficient, although the training phase in these is parameter learning only and not the str...
by marek [BayesFusion]
Sat Oct 24, 2020 5:56 pm
Forum: GeNIe
Topic: Dynamic Bayesian Network (DBN) for time series
Replies: 8
Views: 41

Re: Dynamic Bayesian Network (DBN) for time series

Hi Teng Wang, It is actually not that bad -- I have created DBN models in GeNIe that were based on systems of difference equations, such as predator-prey models. Unlikely you will find another tool -- GeNIe has the most flexible implementation of hybrid Bayesian networks. Finally, we will extend DBN...
by marek [BayesFusion]
Sat Oct 24, 2020 11:06 am
Forum: GeNIe
Topic: Dynamic Bayesian Network (DBN) for time series
Replies: 8
Views: 41

Re: Dynamic Bayesian Network (DBN) for time series

Hi Teng Wang, It is the first -- we have not married equations and DBNs but you are right that it is possible in theory. One way that I deal with it now is creating static networks with equations and deriving CPTs for the equation nodes through discretization. Once the nodes are discretized, I copy ...
by marek [BayesFusion]
Fri Oct 23, 2020 12:08 pm
Forum: GeNIe
Topic: Counting of relationship between a specific variable and the main parent
Replies: 5
Views: 117

Re: Counting of relationship between a specific variable and the main parent

Actually, there is but it is a trick that has not really been designed for this purpose. It will work for discrete Bayesian networks. When the network is open, please invoke the "Strength of Influence" mode (either through a choice in the Network menu or by pressing a corresponding button in the too...
by marek [BayesFusion]
Thu Oct 22, 2020 4:53 pm
Forum: GeNIe
Topic: Model Comparison through log(p)
Replies: 4
Views: 38

Re: Model Comparison through log(p)

Hi Hakan, Log(p), ranging from minus infinity to zero, is not model accuracy but rather an expression of fit of the model to the data. Its numerical value is best used in comparisons between multiple runs of the learning algorithm -- the higher the number, the better (please keep in mind that the nu...
by marek [BayesFusion]
Thu Oct 22, 2020 12:42 pm
Forum: SMILE
Topic: Unexpected evaluation result
Replies: 7
Views: 164

Re: Unexpected evaluation result

Hi Sverre, If the nodes a1 and b1 are not evidence nodes, you can marginalize them to simplify your model. This should work fine. Please just remember that marginalization removes the two nodes while preserving the properties of the rest of the model. After you have marginalized these nodes, entered...
by marek [BayesFusion]
Sat Oct 17, 2020 10:44 am
Forum: SMILE
Topic: Unexpected evaluation result
Replies: 7
Views: 164

Re: Unexpected evaluation result

Hi Sverre, Sorry for a couple of days delay -- I wanted to check what is happening because something funny was actually happening with marginalization of nodes a1 and b1 in your network. We have identify a minor bug in the code that prevents GeNIe from marginalizing these two nodes. In general, it s...
by marek [BayesFusion]
Wed Oct 14, 2020 8:57 am
Forum: SMILE
Topic: Unexpected evaluation result
Replies: 7
Views: 164

Re: Unexpected evaluation result

Hi Sverre, I have never tried it myself but you could possibly reduce previous steps of a multi-step DBN by means of the "Marginalize" operator. This would work well in all situations when you have the time to perform this operation, for example, because you are waiting for input from the user. Marg...
by marek [BayesFusion]
Tue Oct 13, 2020 3:59 pm
Forum: SMILE
Topic: Unexpected evaluation result
Replies: 7
Views: 164

Re: Unexpected evaluation result

Hi Sverre, First of all, I believe you are using an approximate algorithm, as the results are slightly off from the exact computation by clustering algorithm. This, however, should not matter much, just some precision. The error that you are making with your calculation/formula is assuming that a2 a...
by marek [BayesFusion]
Mon Oct 12, 2020 6:00 pm
Forum: GeNIe
Topic: The academy GeNIe always shut down.
Replies: 9
Views: 3194

Re: The academy GeNIe always shut down.

Hi Yajie, Looking at your formula, I'm not sure why you are dividing by 2^17. The second part of the formula seems strange (why are you multiplying by the number of records and also dividing by 10^3? The amount of memory for both learning the parameters and the structure depends on the algorithms us...
by marek [BayesFusion]
Fri Oct 09, 2020 3:24 pm
Forum: GeNIe
Topic: Counting of relationship between a specific variable and the main parent
Replies: 5
Views: 117

Re: Counting of relationship between a specific variable and the main parent

Hi Ashwani, You are right in that the Bayesian Search implementation in GeNIe/SMILE is based on the algorithm proposed by Cooper and Herskovitz. You may also want to look at the paper by David Heckerman "A Tutorial on Learning With Bayesian Networks". It contains a couple of new ideas that enhance C...
by marek [BayesFusion]
Thu Oct 08, 2020 2:23 pm
Forum: GeNIe
Topic: Counting of relationship between a specific variable and the main parent
Replies: 5
Views: 117

Re: Counting of relationship between a specific variable and the main parent

Hi Ashwani, First of all, I suggest that you upgrade to GeNIe 3.0 -- you will like it more! I believe you are asking for limiting the number of parents of a node in the process of learning the model structure. If so, the quickest way to achieve this is to set the "Max Parent Count" parameter (in the...