How to write fitness function in matlab.

[KALYAN ACHARJYA]

Proper elaboration and specific questions gets fast response.

[Shivam Gupta]

Hello Kalyan thanks for your response

I am want to solve Time dependent Vehicle routing problem using Genetic algorithm solver in matlab.

i need assistance to solve this problem like

1) How to write these equation in matlab.

2) What source material/Books to write these equations in matlab.

Answer 1

[Zhangxi Feng]

Please add some more information for your question so we can better help you.

A fittness function is just like any other function except it is expected to return a specific output that will be used by whatever function is calling the fittness function. Looks like you need to implement the function in the image you attached.

By the way, windows have a snipping tool that can easily capture screenshots without needing to use your camera.

Jesse

[Shivam Gupta]

Hello Feng

I want to solve Time Dependent vehicle routing problem using Genetic Algorithm.

Before using GA alogortihm solver in matlab. i have to write these equations which i am not getting how to do.

I want to write these equations in matlab in order to solve my own problem of logistics in my organisations.

[Zhangxi Feng]

It sure is a very complicated problem. The fittness function is basically an error function. See how you need to minimize the primary objective? You just need to convert that minimize into some sort of error. For example, at what point do you consider this function minimized? Maybe if the values don't differ by more than 1e-5 after 10 generations?

The constraints that the objectives are subjected to actually makes your problem easier. I do not understand this particular model but I assume the constraints apply on the input parameters of the two objectives. Simply address this on the inputs.

I know it can be daunting at first because there is no clear template for writting a fittness function, but as I mentioned before, the function is like any other function except it is expected to return an error that genetic algorithm needs to evaluate the generation's population.

function err = myFittnessFunction(par, other inputs)

some_calculated_value = someFunction(par)

err = some_calculated_value - some_expected_value

end

[Shivam Gupta]

Hello Feng

it is a simple problem. we just have to write these equations. which is the main problem for me now.

No of vehicle = 8

We have distance matrix

TIme depedent function of speed need to be made.

i have attached the refernce paper which i am following to solve the problem.

link of Genetic algorithm solver in matlab.

https://www.youtube.com/watch?v=qVHd6T-lSL0

This will give some more insight in this regard.

[Zhangxi Feng]

Although I have implemented a fittness function with genetic algorithm but I never used the GUI. I just straight up programmed it. I am not familiar with the GUI part of the GA or GAmultiobj. Nevertheless, you can first try to create a simple error function that returns anything and see the results for yourself as a start.