Tips for optimisation problem












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I have an optimization (minimize) problem which can be written down as:



$f(vec{x})=sum_1^m{(max(vec{a_1}*x_1,vec{a_2}*x_2,vec{a_3}*x_3,...,vec{a_n}*x_n)-vec{a_0})^2}$



Where $m$ is the size of those vectors $vec{a_i}$ and $n$ is the number of them. The max operation is across the ROWS of the matrix formed by tiling all the a_n column vectors. The sum is across all the components of the final vector containing the squared errors, I didn't know how to indicate that... Basically the result of the max operation is a vector which must be as close to a_0 as possible.



I need some tips in minimizing this, numerical solutions are completely fine, everything is already in a matlab code. $m$ is around 100 and $n$ around 1000.
I'm currently experimenting with Genetic Algorithms but I feel that there is a more clever way, given the simpleness of the function!
Thanks a lot,
Michele










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    0












    $begingroup$


    I have an optimization (minimize) problem which can be written down as:



    $f(vec{x})=sum_1^m{(max(vec{a_1}*x_1,vec{a_2}*x_2,vec{a_3}*x_3,...,vec{a_n}*x_n)-vec{a_0})^2}$



    Where $m$ is the size of those vectors $vec{a_i}$ and $n$ is the number of them. The max operation is across the ROWS of the matrix formed by tiling all the a_n column vectors. The sum is across all the components of the final vector containing the squared errors, I didn't know how to indicate that... Basically the result of the max operation is a vector which must be as close to a_0 as possible.



    I need some tips in minimizing this, numerical solutions are completely fine, everything is already in a matlab code. $m$ is around 100 and $n$ around 1000.
    I'm currently experimenting with Genetic Algorithms but I feel that there is a more clever way, given the simpleness of the function!
    Thanks a lot,
    Michele










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      I have an optimization (minimize) problem which can be written down as:



      $f(vec{x})=sum_1^m{(max(vec{a_1}*x_1,vec{a_2}*x_2,vec{a_3}*x_3,...,vec{a_n}*x_n)-vec{a_0})^2}$



      Where $m$ is the size of those vectors $vec{a_i}$ and $n$ is the number of them. The max operation is across the ROWS of the matrix formed by tiling all the a_n column vectors. The sum is across all the components of the final vector containing the squared errors, I didn't know how to indicate that... Basically the result of the max operation is a vector which must be as close to a_0 as possible.



      I need some tips in minimizing this, numerical solutions are completely fine, everything is already in a matlab code. $m$ is around 100 and $n$ around 1000.
      I'm currently experimenting with Genetic Algorithms but I feel that there is a more clever way, given the simpleness of the function!
      Thanks a lot,
      Michele










      share|cite|improve this question











      $endgroup$




      I have an optimization (minimize) problem which can be written down as:



      $f(vec{x})=sum_1^m{(max(vec{a_1}*x_1,vec{a_2}*x_2,vec{a_3}*x_3,...,vec{a_n}*x_n)-vec{a_0})^2}$



      Where $m$ is the size of those vectors $vec{a_i}$ and $n$ is the number of them. The max operation is across the ROWS of the matrix formed by tiling all the a_n column vectors. The sum is across all the components of the final vector containing the squared errors, I didn't know how to indicate that... Basically the result of the max operation is a vector which must be as close to a_0 as possible.



      I need some tips in minimizing this, numerical solutions are completely fine, everything is already in a matlab code. $m$ is around 100 and $n$ around 1000.
      I'm currently experimenting with Genetic Algorithms but I feel that there is a more clever way, given the simpleness of the function!
      Thanks a lot,
      Michele







      optimization numerical-linear-algebra least-squares






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      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Jan 7 at 12:53







      Michele

















      asked Dec 22 '18 at 11:41









      MicheleMichele

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