Linearly independence after feature embedding












0












$begingroup$


Problem



If feature vectors $mathbf{x}_1, mathbf{x}_2,cdots,mathbf{x}_m$ are linearly independent, argue whether or not their embedding $psi(mathbf{x}_1), psi(mathbf{x}_2),cdots,psi(mathbf{x}_m)$ are linearly independent.



Some Thoughts



The complication here is that the choice of $psi(cdot)$ is not random and often requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable (or we could always do $psi:mathbf{x}_imapsto mathbf{0}$, but this is hardly useful). I am wondering whether this requirement could guarantee that the mapping keeps the linearly independence of original vectors $mathbf{x}_1, mathbf{x}_2,cdots,mathbf{x}_m$.










share|cite|improve this question









$endgroup$












  • $begingroup$
    Could you tell us more precisely what you mean by "requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable"?
    $endgroup$
    – Federico
    Dec 3 '18 at 18:01










  • $begingroup$
    @Federico My bad. Suppose $mathbf{x}_i$'s belongs to two classes, then in original space they are not separable by a hyperplane. But after transformation, i.e. $psi(mathbf{x}_i)$'s, they could be separated by a hyperplane.
    $endgroup$
    – Mr.Robot
    Dec 3 '18 at 18:30






  • 1




    $begingroup$
    Well then it's even more severe that what I wrote. For example, all points from the first class could be mapped to the same vector $v$ and all points from the second class to another vector $w$. From the point of view of machine learning, this is quite a perfect situation, but for sure the images are not linearly independent.
    $endgroup$
    – Federico
    Dec 3 '18 at 18:34






  • 1




    $begingroup$
    It seems to me that the linear independence of the images is not really relevant for the purpose of ML, but I might be wrong.
    $endgroup$
    – Federico
    Dec 3 '18 at 18:35










  • $begingroup$
    @Federico Thank you. I think your example is sufficient for my purpose. Since polynomial and RBF mapping are often used, I have always been struggling with these more complicated mappings but ignore the most straightforward case.
    $endgroup$
    – Mr.Robot
    Dec 3 '18 at 19:09
















0












$begingroup$


Problem



If feature vectors $mathbf{x}_1, mathbf{x}_2,cdots,mathbf{x}_m$ are linearly independent, argue whether or not their embedding $psi(mathbf{x}_1), psi(mathbf{x}_2),cdots,psi(mathbf{x}_m)$ are linearly independent.



Some Thoughts



The complication here is that the choice of $psi(cdot)$ is not random and often requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable (or we could always do $psi:mathbf{x}_imapsto mathbf{0}$, but this is hardly useful). I am wondering whether this requirement could guarantee that the mapping keeps the linearly independence of original vectors $mathbf{x}_1, mathbf{x}_2,cdots,mathbf{x}_m$.










share|cite|improve this question









$endgroup$












  • $begingroup$
    Could you tell us more precisely what you mean by "requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable"?
    $endgroup$
    – Federico
    Dec 3 '18 at 18:01










  • $begingroup$
    @Federico My bad. Suppose $mathbf{x}_i$'s belongs to two classes, then in original space they are not separable by a hyperplane. But after transformation, i.e. $psi(mathbf{x}_i)$'s, they could be separated by a hyperplane.
    $endgroup$
    – Mr.Robot
    Dec 3 '18 at 18:30






  • 1




    $begingroup$
    Well then it's even more severe that what I wrote. For example, all points from the first class could be mapped to the same vector $v$ and all points from the second class to another vector $w$. From the point of view of machine learning, this is quite a perfect situation, but for sure the images are not linearly independent.
    $endgroup$
    – Federico
    Dec 3 '18 at 18:34






  • 1




    $begingroup$
    It seems to me that the linear independence of the images is not really relevant for the purpose of ML, but I might be wrong.
    $endgroup$
    – Federico
    Dec 3 '18 at 18:35










  • $begingroup$
    @Federico Thank you. I think your example is sufficient for my purpose. Since polynomial and RBF mapping are often used, I have always been struggling with these more complicated mappings but ignore the most straightforward case.
    $endgroup$
    – Mr.Robot
    Dec 3 '18 at 19:09














0












0








0





$begingroup$


Problem



If feature vectors $mathbf{x}_1, mathbf{x}_2,cdots,mathbf{x}_m$ are linearly independent, argue whether or not their embedding $psi(mathbf{x}_1), psi(mathbf{x}_2),cdots,psi(mathbf{x}_m)$ are linearly independent.



Some Thoughts



The complication here is that the choice of $psi(cdot)$ is not random and often requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable (or we could always do $psi:mathbf{x}_imapsto mathbf{0}$, but this is hardly useful). I am wondering whether this requirement could guarantee that the mapping keeps the linearly independence of original vectors $mathbf{x}_1, mathbf{x}_2,cdots,mathbf{x}_m$.










share|cite|improve this question









$endgroup$




Problem



If feature vectors $mathbf{x}_1, mathbf{x}_2,cdots,mathbf{x}_m$ are linearly independent, argue whether or not their embedding $psi(mathbf{x}_1), psi(mathbf{x}_2),cdots,psi(mathbf{x}_m)$ are linearly independent.



Some Thoughts



The complication here is that the choice of $psi(cdot)$ is not random and often requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable (or we could always do $psi:mathbf{x}_imapsto mathbf{0}$, but this is hardly useful). I am wondering whether this requirement could guarantee that the mapping keeps the linearly independence of original vectors $mathbf{x}_1, mathbf{x}_2,cdots,mathbf{x}_m$.







linear-algebra machine-learning






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 3 '18 at 17:52









Mr.RobotMr.Robot

35019




35019












  • $begingroup$
    Could you tell us more precisely what you mean by "requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable"?
    $endgroup$
    – Federico
    Dec 3 '18 at 18:01










  • $begingroup$
    @Federico My bad. Suppose $mathbf{x}_i$'s belongs to two classes, then in original space they are not separable by a hyperplane. But after transformation, i.e. $psi(mathbf{x}_i)$'s, they could be separated by a hyperplane.
    $endgroup$
    – Mr.Robot
    Dec 3 '18 at 18:30






  • 1




    $begingroup$
    Well then it's even more severe that what I wrote. For example, all points from the first class could be mapped to the same vector $v$ and all points from the second class to another vector $w$. From the point of view of machine learning, this is quite a perfect situation, but for sure the images are not linearly independent.
    $endgroup$
    – Federico
    Dec 3 '18 at 18:34






  • 1




    $begingroup$
    It seems to me that the linear independence of the images is not really relevant for the purpose of ML, but I might be wrong.
    $endgroup$
    – Federico
    Dec 3 '18 at 18:35










  • $begingroup$
    @Federico Thank you. I think your example is sufficient for my purpose. Since polynomial and RBF mapping are often used, I have always been struggling with these more complicated mappings but ignore the most straightforward case.
    $endgroup$
    – Mr.Robot
    Dec 3 '18 at 19:09


















  • $begingroup$
    Could you tell us more precisely what you mean by "requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable"?
    $endgroup$
    – Federico
    Dec 3 '18 at 18:01










  • $begingroup$
    @Federico My bad. Suppose $mathbf{x}_i$'s belongs to two classes, then in original space they are not separable by a hyperplane. But after transformation, i.e. $psi(mathbf{x}_i)$'s, they could be separated by a hyperplane.
    $endgroup$
    – Mr.Robot
    Dec 3 '18 at 18:30






  • 1




    $begingroup$
    Well then it's even more severe that what I wrote. For example, all points from the first class could be mapped to the same vector $v$ and all points from the second class to another vector $w$. From the point of view of machine learning, this is quite a perfect situation, but for sure the images are not linearly independent.
    $endgroup$
    – Federico
    Dec 3 '18 at 18:34






  • 1




    $begingroup$
    It seems to me that the linear independence of the images is not really relevant for the purpose of ML, but I might be wrong.
    $endgroup$
    – Federico
    Dec 3 '18 at 18:35










  • $begingroup$
    @Federico Thank you. I think your example is sufficient for my purpose. Since polynomial and RBF mapping are often used, I have always been struggling with these more complicated mappings but ignore the most straightforward case.
    $endgroup$
    – Mr.Robot
    Dec 3 '18 at 19:09
















$begingroup$
Could you tell us more precisely what you mean by "requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable"?
$endgroup$
– Federico
Dec 3 '18 at 18:01




$begingroup$
Could you tell us more precisely what you mean by "requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable"?
$endgroup$
– Federico
Dec 3 '18 at 18:01












$begingroup$
@Federico My bad. Suppose $mathbf{x}_i$'s belongs to two classes, then in original space they are not separable by a hyperplane. But after transformation, i.e. $psi(mathbf{x}_i)$'s, they could be separated by a hyperplane.
$endgroup$
– Mr.Robot
Dec 3 '18 at 18:30




$begingroup$
@Federico My bad. Suppose $mathbf{x}_i$'s belongs to two classes, then in original space they are not separable by a hyperplane. But after transformation, i.e. $psi(mathbf{x}_i)$'s, they could be separated by a hyperplane.
$endgroup$
– Mr.Robot
Dec 3 '18 at 18:30




1




1




$begingroup$
Well then it's even more severe that what I wrote. For example, all points from the first class could be mapped to the same vector $v$ and all points from the second class to another vector $w$. From the point of view of machine learning, this is quite a perfect situation, but for sure the images are not linearly independent.
$endgroup$
– Federico
Dec 3 '18 at 18:34




$begingroup$
Well then it's even more severe that what I wrote. For example, all points from the first class could be mapped to the same vector $v$ and all points from the second class to another vector $w$. From the point of view of machine learning, this is quite a perfect situation, but for sure the images are not linearly independent.
$endgroup$
– Federico
Dec 3 '18 at 18:34




1




1




$begingroup$
It seems to me that the linear independence of the images is not really relevant for the purpose of ML, but I might be wrong.
$endgroup$
– Federico
Dec 3 '18 at 18:35




$begingroup$
It seems to me that the linear independence of the images is not really relevant for the purpose of ML, but I might be wrong.
$endgroup$
– Federico
Dec 3 '18 at 18:35












$begingroup$
@Federico Thank you. I think your example is sufficient for my purpose. Since polynomial and RBF mapping are often used, I have always been struggling with these more complicated mappings but ignore the most straightforward case.
$endgroup$
– Mr.Robot
Dec 3 '18 at 19:09




$begingroup$
@Federico Thank you. I think your example is sufficient for my purpose. Since polynomial and RBF mapping are often used, I have always been struggling with these more complicated mappings but ignore the most straightforward case.
$endgroup$
– Mr.Robot
Dec 3 '18 at 19:09










1 Answer
1






active

oldest

votes


















0












$begingroup$

It depends on what you mean by "requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable". If you mean that any of the points $psi(mathbf{x}_i)$ can be linearly separated from the others, then the answer is false.



For instance, the points $(0,0)$, $(1,0)$ and $(0,1)$ are linearly separable in this sense, but are not linearly independent.






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%2f3024431%2flinearly-independence-after-feature-embedding%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









    0












    $begingroup$

    It depends on what you mean by "requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable". If you mean that any of the points $psi(mathbf{x}_i)$ can be linearly separated from the others, then the answer is false.



    For instance, the points $(0,0)$, $(1,0)$ and $(0,1)$ are linearly separable in this sense, but are not linearly independent.






    share|cite|improve this answer









    $endgroup$


















      0












      $begingroup$

      It depends on what you mean by "requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable". If you mean that any of the points $psi(mathbf{x}_i)$ can be linearly separated from the others, then the answer is false.



      For instance, the points $(0,0)$, $(1,0)$ and $(0,1)$ are linearly separable in this sense, but are not linearly independent.






      share|cite|improve this answer









      $endgroup$
















        0












        0








        0





        $begingroup$

        It depends on what you mean by "requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable". If you mean that any of the points $psi(mathbf{x}_i)$ can be linearly separated from the others, then the answer is false.



        For instance, the points $(0,0)$, $(1,0)$ and $(0,1)$ are linearly separable in this sense, but are not linearly independent.






        share|cite|improve this answer









        $endgroup$



        It depends on what you mean by "requires that the resulting $psi(mathbf{x}_i)$'s being linearly separable". If you mean that any of the points $psi(mathbf{x}_i)$ can be linearly separated from the others, then the answer is false.



        For instance, the points $(0,0)$, $(1,0)$ and $(0,1)$ are linearly separable in this sense, but are not linearly independent.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Dec 3 '18 at 18:00









        FedericoFederico

        5,124514




        5,124514






























            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%2f3024431%2flinearly-independence-after-feature-embedding%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

            How to change which sound is reproduced for terminal bell?

            Title Spacing in Bjornstrup Chapter, Removing Chapter Number From Contents

            Can I use Tabulator js library in my java Spring + Thymeleaf project?