About Parameter Learning

The front end.
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niazmahmud
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Joined: Wed Jul 22, 2020 5:51 am

About Parameter Learning

Post by niazmahmud » Thu Jul 23, 2020 2:09 pm

From a complete dataset, i used pc algorithm for structure learning (A DAG was formed). Then parameter learning was done. Then marginal probability was found. But when i further done parameter learning from the same data set, the marginal probability was changed. In example, first gender state 1 was 95% but after further parameter learning it was 5%. What is the reason? Step by step figure is attached below. Thanks in advances.
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shooltz[BayesFusion]
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Re: About Parameter Learning

Post by shooltz[BayesFusion] » Thu Jul 23, 2020 3:17 pm

Please post your data file and the network (after PC, before EM).

niazmahmud
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Joined: Wed Jul 22, 2020 5:51 am

Re: About Parameter Learning

Post by niazmahmud » Thu Jul 23, 2020 3:29 pm

Here it is
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After_EM.xdsl
(6.85 KiB) Downloaded 6 times
Before_EM.xdsl
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modified_ROADSIDE_BBN.csv
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shooltz[BayesFusion]
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Re: About Parameter Learning

Post by shooltz[BayesFusion] » Thu Jul 23, 2020 4:08 pm

The problem probably is related to the automatic matching between data columns and network nodes. Your data file contains numeric indices. During structure learning these indices are converted into string outcome identifiers. The PC/EM does it internally and there's no issue. Later on, when you run EM again, your numeric data is not automatically matched to proper node outcomes - see the attached image and the yellow elements in the center list.

The easiest workaround would be to convert your data to labels (1 -> s1, 2 -> s2, etc). This approach will avoid the mismatch. Alternatively, you can drag'n'drop items in GeNIe's match network and data window, but this of course is a boring manual process.
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match-network-and-data.png
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niazmahmud
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Joined: Wed Jul 22, 2020 5:51 am

Re: About Parameter Learning

Post by niazmahmud » Thu Jul 23, 2020 4:21 pm

Ok. Thanks.

shooltz[BayesFusion]
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Re: About Parameter Learning

Post by shooltz[BayesFusion] » Fri Jul 24, 2020 9:11 am

An update: the automatic matching between integer indices (1,2,...) and the corresponding state names (Xyz1, Xyz2, Xyz3...) has been added to GeNIe. We plan to release the next version of the program later this summer.

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