Multiply block matrices with uneven blocks The Next CEO of Stack OverflowLinear Algebra: Block MultiplyHow to multiply a matrix of block matrices?Proofs of Determinants of Block matricesdiagonalize block matrices with special type of unitary matricesVery basic computations in determinants and matricesForming unitary matrices from identity relationJordan blocks, similarity classDeterminants of block tridiagonal matrices when off-diagonal blocks are not m*m matricesDo matrix multiplication rules apply when multiplying matrices made up of smaller matrices?Question about elementary row operations with block matrices

How long to clear the 'suck zone' of a turbofan after start is initiated?

Anatomically Correct Strange Women In Ponds Distributing Swords

How do I solve this limit?

How to make a variable always equal to the result of some calculations?

Does the Brexit deal have to be agreed by both Houses?

Is a stroke of luck acceptable after a series of unfavorable events?

Why doesn't a table tennis ball float on the surface? How do we calculate buoyancy here?

Opposite of a diet

Why do remote companies require working in the US?

I believe this to be a fraud - hired, then asked to cash check and send cash as Bitcoin

Can a caster that cast Polymorph on themselves stop concentrating at any point even if their Int is low?

How do we know the LHC results are robust?

Should I tutor a student who I know has cheated on their homework?

Only print output after finding pattern

Any way to transfer all permissions from one role to another?

The King's new dress

Visit to the USA with ESTA approved before trip to Iran

Describing a person. What needs to be mentioned?

Can a single photon have an energy density?

Is it my responsibility to learn a new technology in my own time my employer wants to implement?

Anatomically Correct Mesopelagic Aves

Return the Closest Prime Number

What is the difference between "behavior" and "behaviour"?

What is meant by a M next to a roman numeral?



Multiply block matrices with uneven blocks



The Next CEO of Stack OverflowLinear Algebra: Block MultiplyHow to multiply a matrix of block matrices?Proofs of Determinants of Block matricesdiagonalize block matrices with special type of unitary matricesVery basic computations in determinants and matricesForming unitary matrices from identity relationJordan blocks, similarity classDeterminants of block tridiagonal matrices when off-diagonal blocks are not m*m matricesDo matrix multiplication rules apply when multiplying matrices made up of smaller matrices?Question about elementary row operations with block matrices










1












$begingroup$


Is there a way to multiply matrices which are divided into blocks of the form



beginbmatrix
    A&B
endbmatrix



For some $ntimes n $ matrix A and $n times 1$ matrix B with its transpose from the left? Without having to multiply every entry.










share|cite|improve this question









$endgroup$
















    1












    $begingroup$


    Is there a way to multiply matrices which are divided into blocks of the form



    beginbmatrix
        A&B
    endbmatrix



    For some $ntimes n $ matrix A and $n times 1$ matrix B with its transpose from the left? Without having to multiply every entry.










    share|cite|improve this question









    $endgroup$














      1












      1








      1





      $begingroup$


      Is there a way to multiply matrices which are divided into blocks of the form



      beginbmatrix
          A&B
      endbmatrix



      For some $ntimes n $ matrix A and $n times 1$ matrix B with its transpose from the left? Without having to multiply every entry.










      share|cite|improve this question









      $endgroup$




      Is there a way to multiply matrices which are divided into blocks of the form



      beginbmatrix
          A&B
      endbmatrix



      For some $ntimes n $ matrix A and $n times 1$ matrix B with its transpose from the left? Without having to multiply every entry.







      linear-algebra






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked yesterday









      TwistTwist

      636




      636




















          1 Answer
          1






          active

          oldest

          votes


















          2












          $begingroup$

          I assume you mean $beginbmatrix A & B endbmatrix^Tbeginbmatrix A & B endbmatrix$.



          Then multiplication can be done using block matrices



          $beginbmatrix A & B endbmatrix^Tbeginbmatrix A & B endbmatrix=beginbmatrix A^T \ B^T endbmatrix beginbmatrix A & B endbmatrix =beginbmatrix A^TA & A^TB \ B^TA & B^TBendbmatrix $



          Operation is possible if dimensions of block matrices are appropriate for multiplication operation. In this case they are appropriate:



          $ A^TA: $ $n times n , n times n$ result $n times n $



          $ A^TB: $ $n times n , n times 1$ result $n times 1 $



          $ B^TA: $ $1 times n , n times n$ result $1 times n $



          $ B^TB: $ $1 times n , n times 1$ result $1 times 1 $.






          share|cite|improve this answer









          $endgroup$













            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%2f3164319%2fmultiply-block-matrices-with-uneven-blocks%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









            2












            $begingroup$

            I assume you mean $beginbmatrix A & B endbmatrix^Tbeginbmatrix A & B endbmatrix$.



            Then multiplication can be done using block matrices



            $beginbmatrix A & B endbmatrix^Tbeginbmatrix A & B endbmatrix=beginbmatrix A^T \ B^T endbmatrix beginbmatrix A & B endbmatrix =beginbmatrix A^TA & A^TB \ B^TA & B^TBendbmatrix $



            Operation is possible if dimensions of block matrices are appropriate for multiplication operation. In this case they are appropriate:



            $ A^TA: $ $n times n , n times n$ result $n times n $



            $ A^TB: $ $n times n , n times 1$ result $n times 1 $



            $ B^TA: $ $1 times n , n times n$ result $1 times n $



            $ B^TB: $ $1 times n , n times 1$ result $1 times 1 $.






            share|cite|improve this answer









            $endgroup$

















              2












              $begingroup$

              I assume you mean $beginbmatrix A & B endbmatrix^Tbeginbmatrix A & B endbmatrix$.



              Then multiplication can be done using block matrices



              $beginbmatrix A & B endbmatrix^Tbeginbmatrix A & B endbmatrix=beginbmatrix A^T \ B^T endbmatrix beginbmatrix A & B endbmatrix =beginbmatrix A^TA & A^TB \ B^TA & B^TBendbmatrix $



              Operation is possible if dimensions of block matrices are appropriate for multiplication operation. In this case they are appropriate:



              $ A^TA: $ $n times n , n times n$ result $n times n $



              $ A^TB: $ $n times n , n times 1$ result $n times 1 $



              $ B^TA: $ $1 times n , n times n$ result $1 times n $



              $ B^TB: $ $1 times n , n times 1$ result $1 times 1 $.






              share|cite|improve this answer









              $endgroup$















                2












                2








                2





                $begingroup$

                I assume you mean $beginbmatrix A & B endbmatrix^Tbeginbmatrix A & B endbmatrix$.



                Then multiplication can be done using block matrices



                $beginbmatrix A & B endbmatrix^Tbeginbmatrix A & B endbmatrix=beginbmatrix A^T \ B^T endbmatrix beginbmatrix A & B endbmatrix =beginbmatrix A^TA & A^TB \ B^TA & B^TBendbmatrix $



                Operation is possible if dimensions of block matrices are appropriate for multiplication operation. In this case they are appropriate:



                $ A^TA: $ $n times n , n times n$ result $n times n $



                $ A^TB: $ $n times n , n times 1$ result $n times 1 $



                $ B^TA: $ $1 times n , n times n$ result $1 times n $



                $ B^TB: $ $1 times n , n times 1$ result $1 times 1 $.






                share|cite|improve this answer









                $endgroup$



                I assume you mean $beginbmatrix A & B endbmatrix^Tbeginbmatrix A & B endbmatrix$.



                Then multiplication can be done using block matrices



                $beginbmatrix A & B endbmatrix^Tbeginbmatrix A & B endbmatrix=beginbmatrix A^T \ B^T endbmatrix beginbmatrix A & B endbmatrix =beginbmatrix A^TA & A^TB \ B^TA & B^TBendbmatrix $



                Operation is possible if dimensions of block matrices are appropriate for multiplication operation. In this case they are appropriate:



                $ A^TA: $ $n times n , n times n$ result $n times n $



                $ A^TB: $ $n times n , n times 1$ result $n times 1 $



                $ B^TA: $ $1 times n , n times n$ result $1 times n $



                $ B^TB: $ $1 times n , n times 1$ result $1 times 1 $.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered yesterday









                WidawensenWidawensen

                4,72831446




                4,72831446



























                    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%2f3164319%2fmultiply-block-matrices-with-uneven-blocks%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

                    Boston (Lincolnshire) Stedsbyld | Berne yn Boston | NavigaasjemenuBoston Borough CouncilBoston, Lincolnshire

                    Trouble understanding the speech of overseas colleaguesHow can I better understand manager or clients with strong accents?Adding more movement and speech at the fundamental level to a highly-sedentary job?Difficulty in understanding Manager's accent(language and communication)How to adjust yourself where your colleagues are not understanding to you?Understanding manager's expectationsForeigner and colleagues using slangHaving difficulty understanding meetingsHow do you breathe when giving a speech?Trouble Waking Up for Emergencies (On-Call)Problems with colleaguesColleagues feeling insecure when I do my work

                    Ballerup Komuun Stääden an saarpen | Futnuuten | Luke uk diar | Nawigatsjuunwww.ballerup.dkwww.statistikbanken.dk: Tabelle BEF44 (Folketal pr. 1. januar fordelt på byer)Commonskategorii: Ballerup Komuun55° 44′ N, 12° 22′ O