Experimental Results - Maximum
Likelihood Haplotyping
(Superlink v1.4)
(updated November 24th 2004)
Experiment A: (Simulation
Study)
This experiment tested our haplotyping
algorithm on a complex pedigree of moderate size (Figure 2 in (Lin 1996)).
So far, only an approximate haplotype analysis was possible for this pedigree.
We simulated a random haplotype configuration for this pedigree using the
simulation guidelines described by Lin and Speed (1997). This pedigree
consists of 27 individuals and is highly inbred. All individuals, except
those in the first two generations, are typed at 10 polymorphic markers,
each with 5 alleles of equal frequencies. The recombination fraction
between each pair of consecutive markers was set to 0.5.
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Representation (bmp) |
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Superlink |
Superlink |
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ped_expA |
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Experiment C: (Testing Accuracy)
This experiment tested the accuracy
of SimWalk2
(Sobel and Lange, 1996), a state of the art program that uses MCMC.
We tested 75 data sets consisting of 15 to 50 individuals and 1 to 13 markers.
As can be seen from the table below, SimWalk2 found a maximum likelihood
assignment in 45 out of the 75 data sets.
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Representation (bmp) |
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#People | Loops |
Superlink (a) |
SimWalk2 (b) |
| a-b |
-------- * 100 (%) a |
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Experiment D: (Published Disease Data)
We analyzed two published data sets:
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Representation (bmp) |
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Superlink |
SimWalk2 |
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Experiment E: (Stochastic Algorithms) Detailed Results.
This experiment
compared the performance of different stochastic-greedy algorithms. Each
of the stochastic algorithms was run for 1000 iterations after the reduction
rules have been applied. The graphs used were created from simulated pedigree
data.
Experiment F: (Total Run Time) Detailed Results.
This experiment
compared the run time of likelihood computation with the new optimization
algorithm for determining an elimination order (v1.4) to the run time with
the previous optimization algorithm (v1.3). The total run time includes
both optimization time and inference time. We tested 50 randomly
simulated data sets, chosen so that the run times on the new version is
above 10 seconds and below 10 hours.
Experiment G: (Benchmarks) Detailed Results.
This experiment
tested the performance of the three stochastic-greedy algorithms (Min-Weight,
Min-Fill and Weighted Min-Fill), on eight known benchmakrs for Bayesian
networks inference. The stochastic algorithms are run after the reduction
rules have been applied. For each benchmark, we compare between the
elimination cost found by Superlink, the elimination cost found by Hugin6.1
(Andersen et al., 1989; Hugin, 2002) and the best known elimination cost.
Experiment H: (Reduction Rules) Detailed Results.
This experiment
tested the gain due to the reduction rules presented in Eijkhof et al.
(2002). The data sets used are 100 graphs created from simulated
pedigree data.
References: