Clustering efficiency in a discrete time-series












5












$begingroup$


Is it possible to identify the point in time where the cluster separation is at its most in a discrete time series clustering?



Say I have 4 clusters of discrete time series and I want to pick a point in time where I can tell with the least bias which cluster it belongs to after a kmeans clustering, what other criteria than classification success can U use to identify my cluster separation performance?










share|improve this question











$endgroup$




bumped to the homepage by Community 9 mins ago


This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.




















    5












    $begingroup$


    Is it possible to identify the point in time where the cluster separation is at its most in a discrete time series clustering?



    Say I have 4 clusters of discrete time series and I want to pick a point in time where I can tell with the least bias which cluster it belongs to after a kmeans clustering, what other criteria than classification success can U use to identify my cluster separation performance?










    share|improve this question











    $endgroup$




    bumped to the homepage by Community 9 mins ago


    This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.


















      5












      5








      5


      1



      $begingroup$


      Is it possible to identify the point in time where the cluster separation is at its most in a discrete time series clustering?



      Say I have 4 clusters of discrete time series and I want to pick a point in time where I can tell with the least bias which cluster it belongs to after a kmeans clustering, what other criteria than classification success can U use to identify my cluster separation performance?










      share|improve this question











      $endgroup$




      Is it possible to identify the point in time where the cluster separation is at its most in a discrete time series clustering?



      Say I have 4 clusters of discrete time series and I want to pick a point in time where I can tell with the least bias which cluster it belongs to after a kmeans clustering, what other criteria than classification success can U use to identify my cluster separation performance?







      clustering time-series k-means






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Jan 12 '17 at 8:47









      Kasra Manshaei

      3,7991135




      3,7991135










      asked Apr 11 '16 at 5:22









      WazaaWazaa

      261




      261





      bumped to the homepage by Community 9 mins ago


      This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.







      bumped to the homepage by Community 9 mins ago


      This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
























          1 Answer
          1






          active

          oldest

          votes


















          0












          $begingroup$

          Let me start with an important point; what other criteria than classification success can U use to identify my cluster separation performance?:




          1. Classification as an indicator for clustering performance has an internal paradox. If you have the classification the clustering question does not apply anymore. These two concept are coming form two totally different philosophies so I would say be careful if you have already understood the concepts (what you say may make sense in semi-supervised learning which is not in your tags so I assume there is a misunderstanding).

          2. Clustering has no performance evaluation! this is the problem I see most of data scientists struggling with. In practice you may define a good criterion (but honestly, what is good?!!) and deliver your solution, but in research schema there is no evaluation for clustering as the question itself is not well-defined i.e. you never have label to be sure who is who so you need to define closeness of points from which the problem starts; how close is called closeness?!!

          3. Be careful about Curse of Dimensionality while using k-means for time-series clustering (I'm not sure how you do it).


          After these points let's have a look at your question.



          What are time-series? If time-series are pretty non-stationary or simply speaking is the dynamic behind variation is complicated enough, then there is not a one-to-one map for time-series characteristics and time points (imagine a simple ECG signal. It's pretty simple but if you explore research community you will find super sophisticated methods for feature extraction on ECGs. I'm pretty confident finding a time point at which ECGs differ is almost impossible.). You may extract features from your time series or embed it into some n-dimensional manifolds and look at it. In best case you may find some time-related features which describe your time-series and you may find some time-related criteria at which time-series differ (however I'd say it's not likely to find them).



          Assuming time-series are pretty well-behaved (!!) with a simple dynamic (should be super simple). Then a solution might be to define a distance function of time-series which outputs the pair-wise distances of all time-series as a single score. Then the maximum of this function returns the time-point at which these time-series are pretty distinguishable.



          If you provide more information on your data I might be able to give a more detailed precise answer.



          Good Luck!






          share|improve this answer









          $endgroup$














            Your Answer








            StackExchange.ready(function() {
            var channelOptions = {
            tags: "".split(" "),
            id: "557"
            };
            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: false,
            noModals: true,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: null,
            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
            },
            onDemand: true,
            discardSelector: ".discard-answer"
            ,immediatelyShowMarkdownHelp:true
            });


            }
            });














            draft saved

            draft discarded


















            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fdatascience.stackexchange.com%2fquestions%2f11131%2fclustering-efficiency-in-a-discrete-time-series%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












            $begingroup$

            Let me start with an important point; what other criteria than classification success can U use to identify my cluster separation performance?:




            1. Classification as an indicator for clustering performance has an internal paradox. If you have the classification the clustering question does not apply anymore. These two concept are coming form two totally different philosophies so I would say be careful if you have already understood the concepts (what you say may make sense in semi-supervised learning which is not in your tags so I assume there is a misunderstanding).

            2. Clustering has no performance evaluation! this is the problem I see most of data scientists struggling with. In practice you may define a good criterion (but honestly, what is good?!!) and deliver your solution, but in research schema there is no evaluation for clustering as the question itself is not well-defined i.e. you never have label to be sure who is who so you need to define closeness of points from which the problem starts; how close is called closeness?!!

            3. Be careful about Curse of Dimensionality while using k-means for time-series clustering (I'm not sure how you do it).


            After these points let's have a look at your question.



            What are time-series? If time-series are pretty non-stationary or simply speaking is the dynamic behind variation is complicated enough, then there is not a one-to-one map for time-series characteristics and time points (imagine a simple ECG signal. It's pretty simple but if you explore research community you will find super sophisticated methods for feature extraction on ECGs. I'm pretty confident finding a time point at which ECGs differ is almost impossible.). You may extract features from your time series or embed it into some n-dimensional manifolds and look at it. In best case you may find some time-related features which describe your time-series and you may find some time-related criteria at which time-series differ (however I'd say it's not likely to find them).



            Assuming time-series are pretty well-behaved (!!) with a simple dynamic (should be super simple). Then a solution might be to define a distance function of time-series which outputs the pair-wise distances of all time-series as a single score. Then the maximum of this function returns the time-point at which these time-series are pretty distinguishable.



            If you provide more information on your data I might be able to give a more detailed precise answer.



            Good Luck!






            share|improve this answer









            $endgroup$


















              0












              $begingroup$

              Let me start with an important point; what other criteria than classification success can U use to identify my cluster separation performance?:




              1. Classification as an indicator for clustering performance has an internal paradox. If you have the classification the clustering question does not apply anymore. These two concept are coming form two totally different philosophies so I would say be careful if you have already understood the concepts (what you say may make sense in semi-supervised learning which is not in your tags so I assume there is a misunderstanding).

              2. Clustering has no performance evaluation! this is the problem I see most of data scientists struggling with. In practice you may define a good criterion (but honestly, what is good?!!) and deliver your solution, but in research schema there is no evaluation for clustering as the question itself is not well-defined i.e. you never have label to be sure who is who so you need to define closeness of points from which the problem starts; how close is called closeness?!!

              3. Be careful about Curse of Dimensionality while using k-means for time-series clustering (I'm not sure how you do it).


              After these points let's have a look at your question.



              What are time-series? If time-series are pretty non-stationary or simply speaking is the dynamic behind variation is complicated enough, then there is not a one-to-one map for time-series characteristics and time points (imagine a simple ECG signal. It's pretty simple but if you explore research community you will find super sophisticated methods for feature extraction on ECGs. I'm pretty confident finding a time point at which ECGs differ is almost impossible.). You may extract features from your time series or embed it into some n-dimensional manifolds and look at it. In best case you may find some time-related features which describe your time-series and you may find some time-related criteria at which time-series differ (however I'd say it's not likely to find them).



              Assuming time-series are pretty well-behaved (!!) with a simple dynamic (should be super simple). Then a solution might be to define a distance function of time-series which outputs the pair-wise distances of all time-series as a single score. Then the maximum of this function returns the time-point at which these time-series are pretty distinguishable.



              If you provide more information on your data I might be able to give a more detailed precise answer.



              Good Luck!






              share|improve this answer









              $endgroup$
















                0












                0








                0





                $begingroup$

                Let me start with an important point; what other criteria than classification success can U use to identify my cluster separation performance?:




                1. Classification as an indicator for clustering performance has an internal paradox. If you have the classification the clustering question does not apply anymore. These two concept are coming form two totally different philosophies so I would say be careful if you have already understood the concepts (what you say may make sense in semi-supervised learning which is not in your tags so I assume there is a misunderstanding).

                2. Clustering has no performance evaluation! this is the problem I see most of data scientists struggling with. In practice you may define a good criterion (but honestly, what is good?!!) and deliver your solution, but in research schema there is no evaluation for clustering as the question itself is not well-defined i.e. you never have label to be sure who is who so you need to define closeness of points from which the problem starts; how close is called closeness?!!

                3. Be careful about Curse of Dimensionality while using k-means for time-series clustering (I'm not sure how you do it).


                After these points let's have a look at your question.



                What are time-series? If time-series are pretty non-stationary or simply speaking is the dynamic behind variation is complicated enough, then there is not a one-to-one map for time-series characteristics and time points (imagine a simple ECG signal. It's pretty simple but if you explore research community you will find super sophisticated methods for feature extraction on ECGs. I'm pretty confident finding a time point at which ECGs differ is almost impossible.). You may extract features from your time series or embed it into some n-dimensional manifolds and look at it. In best case you may find some time-related features which describe your time-series and you may find some time-related criteria at which time-series differ (however I'd say it's not likely to find them).



                Assuming time-series are pretty well-behaved (!!) with a simple dynamic (should be super simple). Then a solution might be to define a distance function of time-series which outputs the pair-wise distances of all time-series as a single score. Then the maximum of this function returns the time-point at which these time-series are pretty distinguishable.



                If you provide more information on your data I might be able to give a more detailed precise answer.



                Good Luck!






                share|improve this answer









                $endgroup$



                Let me start with an important point; what other criteria than classification success can U use to identify my cluster separation performance?:




                1. Classification as an indicator for clustering performance has an internal paradox. If you have the classification the clustering question does not apply anymore. These two concept are coming form two totally different philosophies so I would say be careful if you have already understood the concepts (what you say may make sense in semi-supervised learning which is not in your tags so I assume there is a misunderstanding).

                2. Clustering has no performance evaluation! this is the problem I see most of data scientists struggling with. In practice you may define a good criterion (but honestly, what is good?!!) and deliver your solution, but in research schema there is no evaluation for clustering as the question itself is not well-defined i.e. you never have label to be sure who is who so you need to define closeness of points from which the problem starts; how close is called closeness?!!

                3. Be careful about Curse of Dimensionality while using k-means for time-series clustering (I'm not sure how you do it).


                After these points let's have a look at your question.



                What are time-series? If time-series are pretty non-stationary or simply speaking is the dynamic behind variation is complicated enough, then there is not a one-to-one map for time-series characteristics and time points (imagine a simple ECG signal. It's pretty simple but if you explore research community you will find super sophisticated methods for feature extraction on ECGs. I'm pretty confident finding a time point at which ECGs differ is almost impossible.). You may extract features from your time series or embed it into some n-dimensional manifolds and look at it. In best case you may find some time-related features which describe your time-series and you may find some time-related criteria at which time-series differ (however I'd say it's not likely to find them).



                Assuming time-series are pretty well-behaved (!!) with a simple dynamic (should be super simple). Then a solution might be to define a distance function of time-series which outputs the pair-wise distances of all time-series as a single score. Then the maximum of this function returns the time-point at which these time-series are pretty distinguishable.



                If you provide more information on your data I might be able to give a more detailed precise answer.



                Good Luck!







                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Jan 12 '17 at 9:14









                Kasra ManshaeiKasra Manshaei

                3,7991135




                3,7991135






























                    draft saved

                    draft discarded




















































                    Thanks for contributing an answer to Data Science 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%2fdatascience.stackexchange.com%2fquestions%2f11131%2fclustering-efficiency-in-a-discrete-time-series%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

                    Ponta tanko

                    Tantalo (mitologio)

                    Erzsébet Schaár