Changes to swap rule and to acc_tuner

[edoardociscato]

In order to implement the swap rule

if evj.value - evi.value < algo["maxdists"][i]
            swap_ev_ij!(algo,i,j)
end

I realized I could simply change the default dist_fun into -, so that the algorithm looks at algo.dist_fun(evj.value, evi.value) being by default -(evj.value, evi.value) but still being editable by users. In addition, I changed the default maxdists to a vector of zeros, so that the default swap rule is simply evj.value < evi.value, as suggested by BGP.

I also introduced a vector acc_tuners as a field of MAlgoBGP so that each chain can have its own value for acc_tuner. This allows for more control on the algorithm. Ideally, one might want to be more restrictive (i.e., higher acc_tuner) on colder chains.

[codecov-io]

Codecov Report

Merging #26 into master will decrease coverage by 0.2%. The diff coverage is 80%.

@@            Coverage Diff             @@
##           master      #26      +/-   ##
==========================================
- Coverage    52.5%   52.29%   -0.21%     
==========================================
  Files          14       14              
  Lines         960      960              
==========================================
- Hits          504      502       -2     
- Misses        456      458       +2

Impacted Files	Coverage Δ
src/mopt/Examples.jl	66.1% <ø> (ø)	:arrow_up:
src/mopt/AlgoBGP.jl	77.25% <80%> (-0.95%)	:arrow_down:

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Continue to review full report at Codecov.

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[coveralls]

Pull Request Test Coverage Report for Build 209

• 4 of 5 (80.0%) changed or added relevant lines in 1 file are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.2%) to 52.292%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/mopt/AlgoBGP.jl	4	5	80.0%
<!--	Total:	4	5

Files with Coverage Reduction	New Missed Lines	%
src/mopt/AlgoBGP.jl	2	77.25%
<!--	Total:	2

Totals
Change from base Build 206:	-0.2%
Covered Lines:	502
Relevant Lines:	960

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💛 - Coveralls

[floswald]

can you just let me know when you are done with this? Im planning to move to julia 0.7 in the coming days, so i may wait (or not) depending on that.

[edoardociscato]

OK, I will do this as soon as possible!