Galapagos bug? integer picking.

Hi David

I've been playing with galapagos solving a problem that requires to find the shortest path over the surface of a box. It worked after tweaking the settings in galapagos but I noticed something wierd, the solution was always the same, and there should be two possible outcomes since the geometry is symmetrical.

I had an integer slider to choose between four possibilities (0 to 3). I noticed that galapagos failed to try the last index of the integer slider in the first run, actually it did but much much less than the other possibilities... I had to trick it to make it work properly. I created a floating point slider from -0.5 to 3.499 and then add an expression to round it.

Seems like a bug to me. Statistically, in the first generation, I would expect galapagos to equally try the four possiblities of an integer slider between 0 and 3, but it doesn't.

bye

Replies to This Discussion

Permalink Reply by Frane Zilic on April 18, 2011 at 6:57am

Here is an image that shows what I'm trying to say.

Galapagos is set to maximize, the slider is set to integers from 0 to 4 and the first run only generates values of 1 and 2.

Permalink Reply by David Rutten on April 18, 2011 at 7:42am

Hi Frane,

yeah looks like a bug.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Sean L on December 13, 2017 at 11:34am

Hi, does anyone have info on how to deal with this? I assume that using floating points and rounding is significantly less efficient than a proper integer representation, but I can't seem to do any better than the rounding implementation in Frane's original post.

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