Fitness Function for Galapagos

I want to use Galapagos to choose a site out of 10 options, in accordance to the distance from certain areas, topological features, traffic approach, commercial availability and some other factors.. how can i set the fitness function? Is the input gonna be through points and their distances or the shape and their center-to-center distances ?

I have provided a file as an example, a providing the rough idea what i intend to do...

Attachments:

Galapagos Analysis for Site Selection.3dm, 56 KB
Galapagos Analysis for Site Selection.ghx, 54 KB

Replies to This Discussion

Permalink Reply by Khizer Ishtiaq on July 4, 2011 at 1:48pm

I have experimented a little, and came up with some sort of understanding of fitness functions, but i need a feedback, if there is any way i can make them even more effective...

I am attaching the updated file...

Attachments:

Galapagos Analysis for Site Selection.ghx, 173 KB

Permalink Reply by Marios Tsiliakos on July 4, 2011 at 2:51pm

Hi khizer,

My approach to this issue would be to to create a mathematical equation that takes all the parameters of yours (maybe organized through a weighted factor) and try to maximize or to minimize the resulting number of this equation.

for instance you can have something like A*factorA + B*factorB / C*factorC - D*factorD where A = preferable areas B= available urban C = major routes D = non preferable areas and try to maximize it through Galapagos.. ( the values might stand for distance , area, altitude, crime rates...it won't be easy but this is one fast way to tackle it.

Regards,

Permalink Reply by Khizer Ishtiaq on July 4, 2011 at 3:11pm

Should i use functions or VB script to create the equation?

And what if instead of providing the whole area to pick from ( like in this case ) , i have series of small areas, how would i deal that using Galapagos??

Permalink Reply by Marios Tsiliakos on July 4, 2011 at 3:23pm

if you feel comfortable with VB.Net go for it. But I think it will be also quite easy to do it only by the grasshopper Functions..

The tricky part here is what strategy are you going to follow and how exactly will you test and validate your data, so that in the end you get only a single number. This number is going to be optimized by galapagos and as a result it will provide you possibly with a local optimum as a solution..

Permalink Reply by David Rutten on July 4, 2011 at 3:27pm

"Should i use functions or VB script to create the equation?"

It doesn't matter. A number is a number is a number.

If you have a collection of number all of which have to be minimized, you can use components like Mass Addition to sum them all together.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Khizer Ishtiaq on July 5, 2011 at 10:26pm

Well, i have been able to improve it to some extend, but i think i can make it more effective...

Fitness function is designed assuming all preferable/non-preferable areas have equal preference, it is then multiplied by the distance from the available site, and then any overlapping area (intersecting) is either added or subtracted...

Also maintain% and Inbreeding is adjusted...

I have noticed cross with dots in the genome map, what does those cross mean? Do they represent genome that are not fit for next generation?

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