| class LoopEngine( OrderEngine ) | Source |
|---|
The LoopEngine tries to unloop a crossing loop.
Only for 2 dimensional TS problems.
Input order
0 1 2 3
15 14 5 4
7 6 13 12
8 9 10 11
The loop crosses between (5,6) and (13,14). By switching the positions of 6 and 13, and reversing the loop in between, a better solution is reached (triangle inequality)
Output order
0 1 2 3
15 14 5 4
12 13 6 7
11 10 9 8
This is NOT a random engine as it only steps in the uphill direction.
It belongs to the class of generalized travelling salesman problems where the parameters of the problem is an ordered list.
The walker is kept when the logLikelihood > lowLhood
Attributes from Engine
walkers, errdis, maxtrials, nstep, slow, rng, report, phantoms, verbose
Author Do Kester.
| LoopEngine( walkers, errdis, copy=None, **kwargs ) |
|---|
Constructor.
Parameters
- walkers : SampleList
walkers to be diffused - errdis : ErrorDistribution
error distribution to be used - copy : LoopEngine
to be copied - kwargs : dict for Engine
"phantoms", "slow", "seed", "verbose"
| copy( ) |
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| executeOnce( kw, lowLhood, dims=[0,1] ) |
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Parameters
- kw : int
walker to diffuse - lowLhood : float
lower limit in logLikelihood - dims : list of 2 ints
dimensions to process over
| Methods inherited from OrderEngine |
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| Methods inherited from Engine |
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- bestBoost( problem, myFitter=None )
- setWalker( kw, problem, allpars, logL, walker=None, fitIndex=None )
- noBoost( walker )
- doBoost( walker )
- domain2Unit( problem, dval, kpar=None )
- unit2Domain( problem, uval, kpar=None )
- startJourney( unitStart )
- calcJourney( unitDistance )
- reportJourney( )
- makeIndex( np, val )
- reportCall( )
- reportSuccess( )
- reportReject( )
- reportFailed( )
- reportBest( )
- printReport( best=False )
- successRate( )
- getUnitMinmax( problem, lowLhood )
- getUnitRange( problem, lowLhood )