BayesFusion Support Forum

I had read out that, but tell me is it necessary to implement that algorithm for calculating inferences?

I'm not quite sure what's your actual question. JT-based algorithm is one (arguably most commonly used) way to implement exact BN inference, but there are other exact algorithms.


And if we ...

For notes on implementing algorithms based on junction tree, try "Inference in Belief Networks: A Procedural Guide" by Huang and Darwiche.

Hi,
I had read out that, but tell me is it necessary to implement that algorithm for calculating inferences? And if we implement that then do we have to ...

Hi All,

Can anybody please tell me how to propagate through the network to calculate the posterior probabilities in bayesian network when no evidence is provided or a single or multiple evidences are provided by the user? :?:
Is there any step by step methodology to be followed to get the ...

Hello Mark,
As I've asked u earlier regarding the zero probabilities(i.e. wht if certain parents states combination is appearing 0 times) and how genie handled that situation, I think in that case laplace correction must have been applied, right? b'coz in that case only it gives those probability ...

hi,
when we set evidences for more than one variable then while claculating the inferences/ marginal probabilities for other variables how the probabilities associated with previous evidnce are propagated for calculating the probabilities with 2nd/new evidence for all other variables? can u please ...

Hi,
while learning the CPTs for each node have u also calculated the marginal probability for each state of that node? b'coz these probabilities will be needed to calculate the inferences after setting the evidence, by using bayes theorem?

Hi,
when we set a particular value for a node in network, then while inferencing we need to calculate postrior probabilities for other nodes, using bayes formula, right? Now suppose i've node A with two values a1, a2 and P(a1) = 0.6 and P(a2) = 0.4 , now if i set the value for that node as a1, does ...

Actually, Mark the same confusion again, before applying EM when the probabilities are assigned to states, there are some parent states combination which appears 0 times in data, but still there are probabilities assigned to those states. similarly some parentchild combination also appears 0 times ...

Hi,
Can anyone tell me please, have you used any correction while calculating conditional probability table, when the parentchild states combination or parent states combination appears zero times in the table?

ok and when any particular combination of states of parent and child occurs '0' times then it gives conditional probability of child as '0' and in case if any particular combination of parents states appear '0' times then then the value of conditional probability of child will be 'infinity' and ...

ok, one more query just to countercheck myself, when we say P(d1|b1&c1) = P(d1,b1,c1)/ P(b1,c1) then we simply need to count no of occurences of d1,b1,c1 appearing together divided by total no of data and same way no of occurences of b1 & c1 together divided by total no of data, right?

Hi,
But can you please help me out to know these things? B'coz i'm trying to do it from many days but not getting my calculations correct. and actually somebody has told me to use parents CPT to calculate childs CPT and it has really confused me b'coz from programming perspective also it will be ...

Hi,
also while calculating CPT for node rejr in the same example of retention_discretized.txt, for many states of rejr, probability comes 'infinity', as the probability of occurence of many combinations of parents values are '0' and hence dividing probabiity of child, parent comb by these prob ...

Hi,
as per u've said earlier i.e. P(d1|b1&c1) = P(d1,b1,c1)/P(b1,c1). then if we use this formula to calculate the probability for node tstsc having parent spend(plz refer the learning example with retention_discretized.txt) then when we calculate P(s1_below_52|s3_28052_33376) = P(s1_below_52, s3 ...

Actually I mean to say,when we set any evidence then the posterior probabillities are calculated for other nodes, then for this calculation purpose do we need to access vector of values of probabilities for each state of each node which is present in the backend?