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Oct
24
comment How can I speed up the classic GA for graph coloring?
But perhaps you can think of a way to relax these conditions or randomize things to make it faster with some probability of stopping?
Oct
24
comment How can I speed up the classic GA for graph coloring?
@Mr.Wizard Combining the annealing with some sort of branch and bound partial backtrack could do the trick... The real problem is getting a 28 coloring in a reasonable time, whatever the method, this is the desired result. I'm thinking I might have to write this in c...
Oct
24
comment How can I speed up the classic GA for graph coloring?
Yes, this is faster but gets stuck at 40 colors. The annealing gets down to 31...
Oct
24
comment How can I speed up the classic GA for graph coloring?
Nice idea, but I feel this approach is doomed as this problem is NP-complete. Isn't the point of approximation algorithms to use clever heuristics and shortcuts to get fast OK solutions? The speed is the issue and any sort of backtracking or exactly solving won't ever work on super large graphs.
Oct
24
comment How can I speed up the classic GA for graph coloring?
@OleksandrR. is correct about requiring domain-specific knowledge to make the recombination framework produce children that actually retain the important genes. In this application, the important genetic information is the partition of the graph into independent sets given by the proper coloring, i.e. the "color classes". So the trick is to splice the two color vectors in a way that preserves the properness of the coloring but also modulates the color classes... And if annealing is used, colors cannot be reduced too quickly, the temperature must be dropped slowly for optimal configurations.
Oct
24
comment How can I speed up the classic GA for graph coloring?
Version 8 has no GraphColor[] functionality... are you able to import the sample inputs from the website? info.univ-angers.fr/pub/porumbel/graphs I believe that you would need v8 Import to get the .col files... I can post them as compressed matrices if you need.
Oct
24
comment How can I speed up the classic GA for graph coloring?
Thanks, see my comments to run the code in version 7.
Oct
23
comment How can I speed up the classic GA for graph coloring?
@DanielLichtblau I'm after a fast upperbound approx algorithm to push stuff, and I'm keen on getting a GA/GP to work. I've tried others, but if a stochastic, deterministic, and annealing method works better who am I to say, just test against the benchmark...
Oct
16
comment How can I have interruptible computations inside a manipulate?
@Mr.Wizard lol! For once, I was actually trying to have a SLOWER function to test this on...
Oct
15
comment How can I have interruptible computations inside a manipulate?
Ok, this looks good, can you use my original example with the function: f[x_] := Total@Table[i^4, {i, x}]
Oct
10
comment How can I make a heatmap of a days in year?
RandomDateList[minYear_:1800, maxYear_:2100] := {RandomInteger[{minYear, maxYear}], RandomInteger[{1, 12}], RandomInteger[{1, 31}], RandomInteger[{0, 23}], RandomInteger[{0, 59}], RandomInteger[{0, 59}]}; RandomDates[n_] := Table[RandomDateList[],{n}]; RandomDates[n_, i_, x_] := Table[RandomDateList[i, x],{n}];
Oct
10
comment How can I make a heatmap of a days in year?
@george Yes, I feel it helps to see the divisions along weeks and months... sort of a birds eye view along all the dimensions...
Oct
10
comment How can I make a heatmap of a days in year?
After gathering by the month, stacking the matrices should be easy but its not
Oct
10
comment How can I make a heatmap of a days in year?
I was almost there, but the hard part is getting the divisions right...
Oct
10
comment How can I make a heatmap of a days in year?
I've checked it out on github, was looking through the java classes...
Oct
8
comment How can I export aligned equations to $\LaTeX$?
It's a Cell style. Just go to Format -> Style -> Item Numbered. It uses a CounterBox to keep track of counts.
Sep
27
comment Looking for “Longest Common Substring” solution
Has anyone got this working on Mac OS X 10.8.2?
Sep
27
comment How to quickly calculate intersections of filled curves?
@freddaneilkline Opencllink is very dicey, even simple questions on this are difficult to answer. Not to mention he probably wants a solution that is device independent.
Sep
27
comment How to quickly calculate intersections of filled curves?
mathematica.stackexchange.com/questions/7174/… only solved unions
Sep
27
comment How to quickly calculate intersections of filled curves?
Great question! I've often wondered this myself...