i have function file i want put limit in variables

Question

Pratik Anandpara 2017-3-17

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https://ww2.mathworks.cn/matlabcentral/answers/330364-i-have-function-file-i-want-put-limit-in-variables

评论： Steven Lord 2017-3-17

function y=myfitness(x)
y= x(1)+x(2)+x(3);
end

this is function file and i want 2<x1<11 ,3<x2<12, 4<x3<12 in this range and want y minimum answer in this range with help of genetic algorithm, i use 'ga' instruction also

   fitfcn=@myfitness;
    nvars=3;
    [x fval]=  ga(fitfcn,nvars);

i want minimize the function output value with this range with the help of Genetic algorithm

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Answer 1

Jan 2017-3-17

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https://ww2.mathworks.cn/matlabcentral/answers/330364-i-have-function-file-i-want-put-limit-in-variables#answer_259147

编辑：Jan 2017-3-17

在 MATLAB Online 中打开

You can limit the values using inputs for ga() - see doc ga:

 x = ga(fitnessfcn,nvars,A,b) finds a local minimum x to fitnessfcn,
 subject to the linear inequalities A*x ≤ b. ga evaluates the matrix
 product A*x as if x is transposed (A*x').

Or better use the lower and upper bounds:

 x = ga(fitnessfcn,nvars,A,b,Aeq,beq,LB,UB) defines a set of lower and
 upper bounds on the design variables, x, so that a solution is found
 in the range LB ≤ x ≤ UB.

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Pratik Anandpara 2017-3-17

2<x1<11 ,3<x2<12, 4<x3<12 for this three unknown variables..how to write instruction for this

Steven Lord 2017-3-17

See the first Example on the documentation page to which Jan linked. It constrains the two variables to be greater than 0 using the variable lb. Just specify a three element vector for lb instead of a two element vector and specify a three element vector for ub as well. [The example didn't have an upper bound on the variable value, so it didn't need to specify ub and didn't specify it.]

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