Variable ordering for exact inference.

[samuelsonric]

I noticed the following comment in the exact inference implementation.

# order impacts performance, but we currently have no ordering heuristics

This patch adds an ordering heuristic. The effect on performance can be dramatic: for example, if we load this network.

julia> using BayesNets, BenchmarkTools

julia> bn = readxdsl("riverland.xdsl"); 

without ordering

julia> @benchmark infer(
           bn,
           [:Economic_Impact, :Electricity_Use],
           evidence=Assignment(:Clay_Content=>1, :Agrochemical_Type=>2))
BenchmarkTools.Trial: 41 samples with 1 evaluation per sample.
 Range (min … max):  118.883 ms … 129.514 ms  ┊ GC (min … max): 0.00% … 4.63%
 Time  (median):     122.314 ms               ┊ GC (median):    2.85%
 Time  (mean ± σ):   123.157 ms ±   2.325 ms  ┊ GC (mean ± σ):  2.64% ± 1.07%

                  █ ▆                                            
  ▄▁▁▁▁▁▁▄▄▁▁▁▁▄▁▇█▇█▇▇▄▄▇▄▇▄▄▁▁▁▁▁▁▄▄▁▁▁▁▄▄▁▁▁▁▄▁▄▁▁▄▁▁▁▁▄▁▁▁▄ ▁
  119 ms           Histogram: frequency by time          130 ms <

 Memory estimate: 55.27 MiB, allocs estimate: 13050.

with ordering

julia> @benchmark infer(
           bn,
           [:Economic_Impact, :Electricity_Use],
           evidence=Assignment(:Clay_Content=>1, :Agrochemical_Type=>2))
BenchmarkTools.Trial: 1605 samples with 1 evaluation per sample.
 Range (min … max):  3.040 ms …  13.740 ms  ┊ GC (min … max): 0.00% … 75.38%
 Time  (median):     3.068 ms               ┊ GC (median):    0.00%
 Time  (mean ± σ):   3.111 ms ± 440.326 μs  ┊ GC (mean ± σ):  0.96% ±  4.51%

   ▆█▅                                                         
  ▄████▆▄▄▃▃▂▂▂▂▂▂▂▁▂▂▁▂▁▁▂▁▂▂▁▂▁▁▁▁▁▂▂▁▁▂▁▂▁▂▂▁▂▁▂▁▁▁▁▁▁▂▁▁▂ ▃
  3.04 ms         Histogram: frequency by time        3.57 ms <

 Memory estimate: 558.35 KiB, allocs estimate: 9740.

[mykelk]

Thanks for this great contribution! I think CI.yml needs to be updated to use actions/cache v4 so that we can run the tests.

[samuelsonric]

hmmm

[mykelk]

I think we want that for cache---not just checkout. It shows up on a different line.

[samuelsonric]

oh, I updated the wrong one

[samuelsonric]

checkout seems to have a version 4 in any case: https://github.com/actions/checkout

[samuelsonric]

CliqueTrees should work with Julia 1.8+. Worth noting that 1.10 is the new LTS!

[mykelk]

I think CliqueTrees requires Julia 1.8 and later. I think the Project.toml needs to be updated to reflect this.

[samuelsonric]

Ok: tests pass locally on Julia 1.8. I updated the Project and the CI.