Island merge is O(N)

[jalberdi004]

Merging and counting the number of islands needs O(N), where N is the lattice size (=total number of lattice sites). There should be a way to count the islands iterating only the sites of merged islands.

Problematic method are countIslands() and computeDiffusivity() of AbstractGrowthLattice class.

[jalberdi004]

Actually, it is not a big problem for a system size of 200x200. It is called roughly 130 times in 1e7 event. Every call needs around 6-7 ms, in total is less than 1s.

Those are test with the version 7f878cf and input
{ "automaticCollections": true, "calculationMode": "concerted", "cartSizeX": 200, "cartSizeY": 200, "coverage": 100, "depositionFlux": 1.0, "doIslandDiffusion": true, "doMultiAtomDiffusion": true, "forceNucleation": false, "justCentralFlake": false, "numberOfSimulations": 1, "outputData": false, "outputDataFormat": [ { "type": "extra" }, { "type": "aea" }, { "type": "mko" } ], "psd": false, "randomSeed": false, "ratesLibrary": "CuNi", "temperature": 55, "withGui": true, "numberOfSteps": 1e7, }

[jalberdi004]

The problem, which can be around 40% of the iteration time is the counting of the events (for the multiplicity study).