# Help !! How to use Genetic Algorithm for maximisation process as it is used for minimisation process?

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ad aymen on 28 Aug 2020
Commented: ad aymen on 9 Sep 2020
How to use Genetic Algorithm for maximisation process as it is used for minimisation process?
There are those who tell you other than the sign equation
but I can't change it cos it is an equation preserved by neural networks
This work improves the linear actuator so that it is sandwiched between LB and LU
I want the most value for ' y '
fitness=@fen;
nvars=2; % Number of variables
LB=[... ...]; %LB Lower bound on x
UB=[... ...]; %UB Upper bound on x
[x,y] = ga(fitness,nvars,[],[],[],[],LB,UB)

Star Strider on 28 Aug 2020
Negate the fitness function to select for the maximum:
[x,y] = ga(@(x)-fitness(x),nvars,[],[],[],[],LB,UB)
Note that this assumes ‘fitness’ has only one argument.
If you are passing extra parameters, this works:
[x,y] = ga(@(x)-fitness(x,a,b),nvars,[],[],[],[],LB,UB)
where ‘a’ and ‘b’ (and perhaps others) are the extra parameters.

ad aymen on 28 Aug 2020
thank you. the problem is solved
Star Strider on 28 Aug 2020
As always, my pleasure!
ad aymen on 9 Sep 2020
Can the ''y'' value be improved to be the maximum value ?

### More Answers (1)

Gifari Zulkarnaen on 28 Aug 2020
Make the fitness function to be 1/f(x) where f(x) is your original maximization.

#### 1 Comment

ad aymen on 28 Aug 2020
thank you