How to find a matrix closest to a given matrix in a Inner product space?











up vote
0
down vote

favorite












Consider $M_2(mathbb{C})$ with the inner product $$langle A, B rangle = trace(B^*A)$$ where $*$ is conjugate transpose.
Find the closest element of the complex symmetric $2times 2$ matrices to $$A = begin{bmatrix}1&-i\ i&1end{bmatrix}$$How to approach this problem?










share|cite|improve this question


























    up vote
    0
    down vote

    favorite












    Consider $M_2(mathbb{C})$ with the inner product $$langle A, B rangle = trace(B^*A)$$ where $*$ is conjugate transpose.
    Find the closest element of the complex symmetric $2times 2$ matrices to $$A = begin{bmatrix}1&-i\ i&1end{bmatrix}$$How to approach this problem?










    share|cite|improve this question
























      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      Consider $M_2(mathbb{C})$ with the inner product $$langle A, B rangle = trace(B^*A)$$ where $*$ is conjugate transpose.
      Find the closest element of the complex symmetric $2times 2$ matrices to $$A = begin{bmatrix}1&-i\ i&1end{bmatrix}$$How to approach this problem?










      share|cite|improve this question













      Consider $M_2(mathbb{C})$ with the inner product $$langle A, B rangle = trace(B^*A)$$ where $*$ is conjugate transpose.
      Find the closest element of the complex symmetric $2times 2$ matrices to $$A = begin{bmatrix}1&-i\ i&1end{bmatrix}$$How to approach this problem?







      matrices inner-product-space least-squares






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Nov 24 at 7:35









      Mittal G

      1,192515




      1,192515






















          1 Answer
          1






          active

          oldest

          votes

















          up vote
          1
          down vote



          accepted











          1. Pick a basis $(e_1,e_2,e_3)$ of the space of all $2times2$ matrices.

          2. Use Gram-Schmidt to create from it an orthnormal basis $(f_1,f_2,f_3)$.

          3. The answer to your problem will be $langle A,f_1rangle f_1+langle A,f_2rangle f_2+langle A,f_3rangle f_3$






          share|cite|improve this answer





















            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%2f3011284%2fhow-to-find-a-matrix-closest-to-a-given-matrix-in-a-inner-product-space%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes








            up vote
            1
            down vote



            accepted











            1. Pick a basis $(e_1,e_2,e_3)$ of the space of all $2times2$ matrices.

            2. Use Gram-Schmidt to create from it an orthnormal basis $(f_1,f_2,f_3)$.

            3. The answer to your problem will be $langle A,f_1rangle f_1+langle A,f_2rangle f_2+langle A,f_3rangle f_3$






            share|cite|improve this answer

























              up vote
              1
              down vote



              accepted











              1. Pick a basis $(e_1,e_2,e_3)$ of the space of all $2times2$ matrices.

              2. Use Gram-Schmidt to create from it an orthnormal basis $(f_1,f_2,f_3)$.

              3. The answer to your problem will be $langle A,f_1rangle f_1+langle A,f_2rangle f_2+langle A,f_3rangle f_3$






              share|cite|improve this answer























                up vote
                1
                down vote



                accepted







                up vote
                1
                down vote



                accepted







                1. Pick a basis $(e_1,e_2,e_3)$ of the space of all $2times2$ matrices.

                2. Use Gram-Schmidt to create from it an orthnormal basis $(f_1,f_2,f_3)$.

                3. The answer to your problem will be $langle A,f_1rangle f_1+langle A,f_2rangle f_2+langle A,f_3rangle f_3$






                share|cite|improve this answer













                1. Pick a basis $(e_1,e_2,e_3)$ of the space of all $2times2$ matrices.

                2. Use Gram-Schmidt to create from it an orthnormal basis $(f_1,f_2,f_3)$.

                3. The answer to your problem will be $langle A,f_1rangle f_1+langle A,f_2rangle f_2+langle A,f_3rangle f_3$







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Nov 24 at 7:49









                José Carlos Santos

                147k22117218




                147k22117218






























                    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.





                    Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


                    Please pay close attention to the following guidance:


                    • 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.


                    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%2f3011284%2fhow-to-find-a-matrix-closest-to-a-given-matrix-in-a-inner-product-space%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

                    Probability when a professor distributes a quiz and homework assignment to a class of n students.

                    Aardman Animations

                    Are they similar matrix