Re: [Extra Speed] Islik
Ted Brathwaite
For Constraint Streams and Drools score calculation (Deprecated),OptaPlanner needs to extract the problem fact instances from the solution instance.It gets those collection(s) by calling every method (or field) that is annotated with @ProblemFactCollectionProperty.All objects returned by those methods are available to use by Constraint Streams or Drools rules.For example in NQueens all Column and Row instances are problem facts.
A Solver should only be accessed from a single thread, except for the methods that are specifically documented in javadoc as being thread-safe.The solve() method hogs the current thread.This can cause HTTP timeouts for REST services and it requires extra code to solve multiple datasets in parallel.To avoid such issues, use a SolverManager instead.
After solving a problem, the Solver will log the score calculation speed per second.This is a good measurement of Score calculation performance,despite that it is affected by non score calculation execution time.It depends on the problem scale of the problem dataset.Normally, even for high scale problems, it is higher than 1000, except if you are using an EasyScoreCalculator.
When improving your score calculation, focus on maximizing the score calculation speed, instead of maximizing the best score.A big improvement in score calculation can sometimes yield little or no best score improvement, for example when the algorithm is stuck in a local or global optima.If you are watching the calculation speed instead, score calculation improvements are far more visible.
Not all score constraints have the same performance cost.Sometimes one score constraint can kill the score calculation performance outright.Use the Benchmarker to do a one minute run and check what happens to the score calculation speed if you comment out all but one of the score constraints.
For comparison: the minimal number of atoms in the known universe (10^80). As a planning problem gets bigger, the search space tends to blow up really fast.Adding only one extra planning entity or planning value can heavily multiply the running time of some algorithms.
A rule engine, such as Drools, is great for calculating the score of a solution of a planning problem.It makes it easy and scalable to add additional soft or hard constraints.It does incremental score calculation (deltas) without any extra code.However it tends to be not suitable to actually find new solutions.
It is counter-effective to set a moveThreadCountthat is higher than the number of available CPU cores,as that will slow down the score calculation speed.One good reason to do it anyway, is to reproduce a bug of a high-end production machine.
For constraint streams and Drools score calculation,OptaPlanner needs to extract the problem fact instances from the solution instance.It gets those collection(s) by calling every method (or field) that is annotated with @ProblemFactCollectionProperty.All objects returned by those methods are available to use by the constraint streams or Drools rules.For example in NQueens all Column and Row instances are problem facts.
Bavet is an experimental implementation that focuses on raw speed and provides superior performance.However, it lacks features and therefore many of the examples are not supported.To try it out, implement the ConstraintProvider interface and use the following in your solver config:
A rule engine, such as Drools Expert, is great for calculating the score of a solution of a planning problem. It makes it easy and scalable to add additional soft or hard constraints such as, "a teacher should not teach more than seven hours a day". It does delta-based score calculation without any extra code. However it tends to be not suitable to actually find new solutions.
To lower verbosity, the common parts of multiple elements are extracted to the element.Every property can still be overwritten per element.Note that inherited solver phases such as or are not overwrittenbut instead are added to the tail of the solver phases list.
Useful for comparing different score calculators and/or constraint implementations(presuming that the solver configurations do not differ otherwise).Also useful to measure the scalability cost of an extra constraint.
Even though Busnel (Busnel, 1976) and Baskan (Baskan, 1968) were participated within the same research group during the research on TWsL in 1967, some phonetic inferences in (Baskan, 1968) have not been in (Busnel, 1976). It is interestingly stated in (Baskan, 1968) that according to the listening and understanding tests performed in Kuskoy, people has a tendency to understand the TWsL with three vowels (i, œ, o) and three consonants (f, tʃ, k) even if Turkish Language has thirty-two phonemes including eight vowels (Figure 1) and twenty-four consonants (Table 1). According to Baskan, thirty-two Turkish phoneme family was piled up within these six distinct sounds in TWsL, even though a whistling person is described as tried to make all the necessary movements to speak the same sentence. The reason of this explained in (Baskan, 1968) as follows; both vowels (i, œ, o) and consonants (f, tʃ, k) have front, middle and back articulation points respectively in accordance with the physiology of whistling in TWsL. The main articulation points are front and back points. Middle point can be regarded as an average of these two. /o/ and /tʃ/ voices carry the heaviest load of the TWsL for vowels and consonants respectively. Vocal cords do not vibrate while whistling and therefore voiced consonants (such as /c/, /d/) cannot be produced. Furthermore, because lips are not closed, bilabial consonants (such as /p/, /b/, /m/) can be produced as /f/. Because of the tongue, which satisfies the modulation by sticking to palate while whistling, many phonemes approximated to / tʃ/. Similarly, because semi-constricted condition of lips ends in parallel with the small rise of tongue, the condition of voice system similar to vowel /o/. For all these reasons, heavy load of TWsL is carried by /o/ and / tʃ/ sounds as can be seen from the Table 1. On the other hand, because a whistling person performs all necessary movements for articulating, he assumes he can extract all the necessary sounds even if he can only extract them as 3 vowels and 3 consonants. Moreover, the listening person tries to decode all acoustic properties of whistling and can understand them as 3 vowels and 3 consonants (Baskan, 1968).
Polferries har ställt in sin färjetrafik mellan Sverige och Polen under söndagen och måndagen till följd av Hans.
Ovädret väntas ligga kvar över landet till och med torsdag. Flera räddningstjänster, bland annat i Göteborg och flera orter i Värmland har höjt sin beredskap och att kalla in extra personal.