Download presentation
Presentation is loading. Please wait.
Published byMorgan French Modified over 5 years ago
1
Approximating the Partition Function by Deleting and then Correcting for Model Edges
Arthur Choi and Adnan Darwiche University of California, Los Angeles
2
Edge Deletion: Idea Delete an edge Model M Model M'
3
Deleting an Equivalence Edge
j
4
Deleting an Equivalence Edge
j j
5
Deleting an Equivalence Edge
j
6
Deleting an Equivalence Edge
j
7
Deleting an Equivalence Edge
j
8
Deleting an Equivalence Edge
j
9
Edge Parameters: ED-BP
i j
10
Edge Parameters: ED-BP
i j Conditions on edge parameters imply an iterative algorithm: ED-BP
11
Edge Parameters: ED-BP
i j Yields a weaker notion of equivalence:
12
A Spectrum of Approximations
ED-BP networks: [CD06]
13
A Spectrum of Approximations
ED-BP networks: [CD06] Exact Inference
14
A Spectrum of Approximations
ED-BP networks: [CD06] Loopy BP marginals Exact Inference
15
A Spectrum of Approximations
ED-BP networks: [CD06] Loopy BP marginals Exact Inference partition function?
16
A Partition Function i j
17
An Easy Case: Delete a Single Edge
Prop.: If MI(Xi,Xj) = 0 in ED-BP network M', then: where i j
18
An Easy Case: Delete a Single Edge
Prop.: If MI(Xi,Xj) = 0 in ED-BP network M', then: where i With multiple edges deleted (ZERO-EC): j
19
Bethe Free Energy and ZERO-EC
Bethe free energy approximation: as a partition function approximation:
20
Bethe Free Energy is ZERO-EC
Bethe free energy approximation: as a partition function approximation: Theorem: The Bethe approximation is ZERO-EC when M' is a tree :
21
An Easy Case: Delete a Single Edge
Prop.: If MI(Xi,Xj) = 0 in ED-BP network M', then: where i With multiple edges deleted (ZERO-EC): j
22
An Easy Case: Delete a Single Edge
Prop.: For any edge in an ED-BP network M', then where i With multiple edges deleted (GENERAL-EC): j
23
Overview tree exact exact marginals marginals LBP IJGP
24
joingraph free energies
Overview tree exact exact marginals marginals LBP IJGP joingraph free energies zero-EC Bethe exact Z
25
Overview tree exact exact marginals marginals LBP IJGP
joingraph free energies zero-EC Bethe exact Z improved approximations (higher order EP/GBP energies) general-EC
26
joingraph free energies
Overview tree exact exact marginals marginals LBP IJGP joingraph free energies zero-EC Bethe exact Z recover edges general-EC
27
Edge Recovery: ZERO-EC
i j Recover edges with largest MI(Xi;Xj)
28
Edge Recovery: GENERAL-EC
j i t s Recover edges with largest MI(Xi,Xj; Xs,Xt)
29
Edge Recovery Bethe exact Z 6x6 grid EC-Z,rand 0.07 0.06 0.05
relative error 0.04 0.03 0.02 exact Z 0.01 edges recovered 25
30
Edge Recovery Bethe exact Z 6x6 grid EC-Z,rand EC-G,rand 0.07 0.06
0.05 relative error 0.04 0.03 0.02 exact Z 0.01 edges recovered 25
31
Edge Recovery Bethe exact Z 6x6 grid EC-Z,rand EC-G,rand 0.07 EC-Z,MI
0.06 0.05 relative error 0.04 0.03 0.02 exact Z 0.01 edges recovered 25
32
Edge Recovery Bethe exact Z 6x6 grid EC-Z,rand EC-G,rand 0.07 EC-Z,MI
EC-G,MI 0.06 0.05 relative error 0.04 0.03 0.02 exact Z 0.01 edges recovered 25
33
Edge Recovery Bethe exact Z 6x6 grid EC-Z,rand EC-G,rand 0.07 EC-Z,MI
EC-G,MI 0.06 EC-G,MI2 0.05 relative error 0.04 0.03 0.02 exact Z 0.01 edges recovered 25
34
Edge Recovery
35
joingraph free energies
Overview tree exact exact marginals marginals LBP IJGP/GBP joingraph free energies zero-EC Bethe exact Z recover edges general-EC
36
joingraph free energies
Overview tree exact exact marginals marginals LBP IJGP/GBP joingraph free energies zero-EC Bethe exact Z partial corrections: general-EC
37
Partial Correction pigs 1 ED-BP (Bethe) 0.8 0.6 relative error 0.4
general-EC 0.2 500 1000 1500 2000 2500 3000 time (ms)
38
Partial Correction pigs 1 ED-BP (Bethe) 0.8 0.6 relative error
soft-sep see AAAI’08 0.4 general-EC 0.2 500 1000 1500 2000 2500 3000 time (ms)
39
Partial Correction
40
joingraph free energies
Overview tree exact exact marginals marginals LBP IJGP/GBP joingraph free energies zero-EC Bethe exact Z general-EC
41
joingraph free energies
Overview tree exact exact marginals marginals LBP IJGP/GBP marginal corrections (AAAI'08) joingraph free energies zero-EC Bethe exact Z general-EC
42
Thanks!
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.