Tips for optimisation problem












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












    $begingroup$


    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






      share|cite|improve this question















      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

      12




      12






















          0






          active

          oldest

          votes











          Your Answer





          StackExchange.ifUsing("editor", function () {
          return StackExchange.using("mathjaxEditing", function () {
          StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
          StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
          });
          });
          }, "mathjax-editing");

          StackExchange.ready(function() {
          var channelOptions = {
          tags: "".split(" "),
          id: "69"
          };
          initTagRenderer("".split(" "), "".split(" "), channelOptions);

          StackExchange.using("externalEditor", function() {
          // Have to fire editor after snippets, if snippets enabled
          if (StackExchange.settings.snippets.snippetsEnabled) {
          StackExchange.using("snippets", function() {
          createEditor();
          });
          }
          else {
          createEditor();
          }
          });

          function createEditor() {
          StackExchange.prepareEditor({
          heartbeatType: 'answer',
          autoActivateHeartbeat: false,
          convertImagesToLinks: true,
          noModals: true,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: 10,
          bindNavPrevention: true,
          postfix: "",
          imageUploader: {
          brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
          contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
          allowUrls: true
          },
          noCode: true, onDemand: true,
          discardSelector: ".discard-answer"
          ,immediatelyShowMarkdownHelp:true
          });


          }
          });














          draft saved

          draft discarded


















          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3049345%2ftips-for-optimisation-problem%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown

























          0






          active

          oldest

          votes








          0






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes
















          draft saved

          draft discarded




















































          Thanks for contributing an answer to Mathematics Stack Exchange!


          • Please be sure to answer the question. Provide details and share your research!

          But avoid



          • Asking for help, clarification, or responding to other answers.

          • Making statements based on opinion; back them up with references or personal experience.


          Use MathJax to format equations. MathJax reference.


          To learn more, see our tips on writing great answers.




          draft saved


          draft discarded














          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3049345%2ftips-for-optimisation-problem%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown





















































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown

































          Required, but never shown














          Required, but never shown












          Required, but never shown







          Required, but never shown







          Popular posts from this blog

          Mario Kart Wii

          What does “Dominus providebit” mean?

          Antonio Litta Visconti Arese