# how can i make ga code to set a specific values to a parameter

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zenhom mohamed on 25 Nov 2018
Answered: Alan Weiss on 27 Nov 2018
hallo, i am making optimization by genetic algorithm (ga)...i know that when you run the code, random values for each parameter are assumed..my question: if there is a parameter i want the code to assume a specific values to it at each iter?

Star Strider on 25 Nov 2018
I am not certain what you are asking.
If you have a parameter you want not to vary (you already know the optimum value), fix it in your fitness function, and optimise the other parameters you want to estimate. This is likely more efficient than fixing it with the ‘lb’ and ‘ub’ arguments, alghtough if you want it to vary only within a narrow range, you can use those arguments to constrain it.
zenhom mohamed on 27 Nov 2018
i mean that: if x(1) represents a size of a generator which takes a specific values according to the manifacture (for ex. 50, 100, 150 kw only), i want the ga code not to set any random value for x(1), i want it to set one value of these three values at each iteration
Star Strider on 27 Nov 2018
My pleasure.
Set ‘x(1)’, and whatever other parameters you want not to vary, to constant values in your fitness function, and do not include them in the parameters you want to optimise.

Alan Weiss on 27 Nov 2018
It sounds to me as if you have a discrete set of values to choose from. Use the technique of Mixed Integer Optimization, as shown in the example Solving a Mixed Integer Engineering Design Problem Using the Genetic Algorithm.
Alan Weiss
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