Re: [Qgis-user] Draw Ellipse/Polygons for areas of maximum concentration
As you mention degree as unit for the distance, I assume that you are working with unprojected data. 1 degree is a huge distance, so consequently, all points will fall into this area and form one cluster. You'll have to project your data and find some meaningful value for the distance to get different clusters. On 30.04.21 02:02, krishna Ayyala wrote: Nyall, Thanks for your reply. I have used the "dbscan clustering". In this, the default values for "Minimum Cluster Size" is 5 and Max distance between cluster points is 1 degrees. I ran with the same default values. I am getting output with the layer name "Clusters". This has generated a new field "Cluster_ID". All the points have same Cluster_ID i.e. 1. This has also generated new field called "Cluster_Size". All the points have same cluster size i.e. 1699. Can you please help me on how to get 4 different cluster ID's. Regards. On Thu, Apr 29, 2021 at 4:29 PM Nyall Dawson wrote: On Fri, 30 Apr 2021 at 08:25, krishna Ayyala wrote: Chris, Thanks for the reply. Yes, I did run k-means clustering for 4 clusters. It is creating a new layer called "clusters". This layer has a field called Cluster_id, ranging from 1 to 4. But, this method is considering all the points within the circle. I am looking for the points outside the ellipses to be omitted (should not be considered) In this case "dbscan clustering" is more appropriate. . Also K-means clustering is not generating any polygons/ellipses. We have to identify a cluster based on the Cluster_ID. I am curious if there is any tool within Qgis that can produce results similar to the circle with ellipses? What you could do is dissolve the points based on the cluster_id field, and then generate convex (or concave) hulls enclosing each set of points. You won't get ellipses, but you'll get polygons describing the boundaries. (And it would be relatively straightforward to wrap up these steps into a single graphical model so that you have one tool which gives the desired output!). Nyall Regards. On Thu, Apr 29, 2021 at 3:56 PM chris hermansen wrote: Krishna and list, On Thu, Apr 29, 2021 at 2:51 PM krishna Ayyala wrote: Hello, I have a circle in which there are randomly distributed points as below. Each point is a customer. [image: image.png] Is there a tool within QGIS that can automatically generate four polygons or four ellipses such as below. These polygons are the areas of maximum concentration of the customers? [image: image.png] You could try k-means clustering https://docs.qgis.org/3.4/en/docs/user_manual/processing_algs/qgis/vectoranalysis.html#k-means-clustering -- Chris Hermansen · clhermansen "at" gmail "dot" com C'est ma façon de parler. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Draw Ellipse/Polygons for areas of maximum concentration
On Fri, 30 Apr 2021 at 15:01, chris hermansen wrote: > > Krishna and list, > > On Thu, Apr 29, 2021 at 7:45 PM chris hermansen wrote: >> >> Krishna and list >> >> On Thu, Apr 29, 2021, 15:24 krishna Ayyala wrote: >>> >>> Chris, >>> Thanks for the reply. Yes, I did run k-means clustering for 4 clusters. It >>> is creating a new layer called "clusters". This layer has a field called >>> Cluster_id, ranging from 1 to 4. But, this method is considering all the >>> points within the circle. I am looking for the points outside the ellipses >>> to be omitted (should not be considered). Also K-means clustering is not >>> generating any polygons/ellipses. We have to identify a cluster based on >>> the Cluster_ID. I am curious if there is any tool within Qgis that can >>> produce results similar to the circle with ellipses? >> >> >> If you symbolize your points by colour according to the cluster_id does the >> clustering look acceptable to you? >> >>> > > Thinking about your diagram, maybe you want to fit ellipses to point > clusters. If that's the case, maybe this paper is of some help: > > https://www.researchgate.net/publication/276433770_Multiple_ellipse_fitting_by_center-based_clustering/fulltext/56293cc208aef25a243d5d3a/Multiple-ellipse-fitting-by-center-based-clustering.pdf You could try this plugin : https://plugins.qgis.org/plugins/SDEllipse/ Nyall > > I imagine you'd need to program this yourself. > > > -- > Chris Hermansen · clhermansen "at" gmail "dot" com > > C'est ma façon de parler. > ___ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Draw Ellipse/Polygons for areas of maximum concentration
Krishna and list, On Thu, Apr 29, 2021 at 7:45 PM chris hermansen wrote: > Krishna and list > > On Thu, Apr 29, 2021, 15:24 krishna Ayyala > wrote: > >> Chris, >> Thanks for the reply. Yes, I did run k-means clustering for 4 clusters. >> It is creating a new layer called "clusters". This layer has a field called >> Cluster_id, ranging from 1 to 4. But, this method is considering all the >> points within the circle. I am looking for the points outside the ellipses >> to be omitted (should not be considered). Also K-means clustering is not >> generating any polygons/ellipses. We have to identify a cluster based on >> the Cluster_ID. I am curious if there is any tool within Qgis that can >> produce results similar to the circle with ellipses? >> > > If you symbolize your points by colour according to the cluster_id does > the clustering look acceptable to you? > > >> Thinking about your diagram, maybe you want to fit ellipses to point clusters. If that's the case, maybe this paper is of some help: https://www.researchgate.net/publication/276433770_Multiple_ellipse_fitting_by_center-based_clustering/fulltext/56293cc208aef25a243d5d3a/Multiple-ellipse-fitting-by-center-based-clustering.pdf I imagine you'd need to program this yourself. -- Chris Hermansen · clhermansen "at" gmail "dot" com C'est ma façon de parler. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Draw Ellipse/Polygons for areas of maximum concentration
Krishna and list On Thu, Apr 29, 2021, 15:24 krishna Ayyala wrote: > Chris, > Thanks for the reply. Yes, I did run k-means clustering for 4 clusters. It > is creating a new layer called "clusters". This layer has a field called > Cluster_id, ranging from 1 to 4. But, this method is considering all the > points within the circle. I am looking for the points outside the ellipses > to be omitted (should not be considered). Also K-means clustering is not > generating any polygons/ellipses. We have to identify a cluster based on > the Cluster_ID. I am curious if there is any tool within Qgis that can > produce results similar to the circle with ellipses? > If you symbolize your points by colour according to the cluster_id does the clustering look acceptable to you? > ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Draw Ellipse/Polygons for areas of maximum concentration
Nyall, Thanks for your reply. I have used the "dbscan clustering". In this, the default values for "Minimum Cluster Size" is 5 and Max distance between cluster points is 1 degrees. I ran with the same default values. I am getting output with the layer name "Clusters". This has generated a new field "Cluster_ID". All the points have same Cluster_ID i.e. 1. This has also generated new field called "Cluster_Size". All the points have same cluster size i.e. 1699. Can you please help me on how to get 4 different cluster ID's. Regards. On Thu, Apr 29, 2021 at 4:29 PM Nyall Dawson wrote: > > > On Fri, 30 Apr 2021 at 08:25, krishna Ayyala > wrote: > >> Chris, >> Thanks for the reply. Yes, I did run k-means clustering for 4 clusters. >> It is creating a new layer called "clusters". This layer has a field called >> Cluster_id, ranging from 1 to 4. But, this method is considering all the >> points within the circle. I am looking for the points outside the ellipses >> to be omitted (should not be considered) >> > > In this case "dbscan clustering" is more appropriate. > > >> . Also K-means clustering is not generating any polygons/ellipses. We >> have to identify a cluster based on the Cluster_ID. I am curious if there >> is any tool within Qgis that can produce results similar to the circle with >> ellipses? >> > > What you could do is dissolve the points based on the cluster_id field, > and then generate convex (or concave) hulls enclosing each set of points. > You won't get ellipses, but you'll get polygons describing the boundaries. > (And it would be relatively straightforward to wrap up these steps into a > single graphical model so that you have one tool which gives the desired > output!). > > Nyall > > > > >> >> Regards. >> >> On Thu, Apr 29, 2021 at 3:56 PM chris hermansen >> wrote: >> >>> Krishna and list, >>> >>> On Thu, Apr 29, 2021 at 2:51 PM krishna Ayyala >>> wrote: >>> Hello, I have a circle in which there are randomly distributed points as below. Each point is a customer. [image: image.png] Is there a tool within QGIS that can automatically generate four polygons or four ellipses such as below. These polygons are the areas of maximum concentration of the customers? [image: image.png] You could try k-means clustering >>> >>> >>> https://docs.qgis.org/3.4/en/docs/user_manual/processing_algs/qgis/vectoranalysis.html#k-means-clustering >>> >>> -- >>> Chris Hermansen · clhermansen "at" gmail "dot" com >>> >>> C'est ma façon de parler. >>> >> ___ >> Qgis-user mailing list >> Qgis-user@lists.osgeo.org >> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user >> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user >> > ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Draw Ellipse/Polygons for areas of maximum concentration
On Fri, 30 Apr 2021 at 08:25, krishna Ayyala wrote: > Chris, > Thanks for the reply. Yes, I did run k-means clustering for 4 clusters. It > is creating a new layer called "clusters". This layer has a field called > Cluster_id, ranging from 1 to 4. But, this method is considering all the > points within the circle. I am looking for the points outside the ellipses > to be omitted (should not be considered) > In this case "dbscan clustering" is more appropriate. > . Also K-means clustering is not generating any polygons/ellipses. We have > to identify a cluster based on the Cluster_ID. I am curious if there is any > tool within Qgis that can produce results similar to the circle with > ellipses? > What you could do is dissolve the points based on the cluster_id field, and then generate convex (or concave) hulls enclosing each set of points. You won't get ellipses, but you'll get polygons describing the boundaries. (And it would be relatively straightforward to wrap up these steps into a single graphical model so that you have one tool which gives the desired output!). Nyall > > Regards. > > On Thu, Apr 29, 2021 at 3:56 PM chris hermansen > wrote: > >> Krishna and list, >> >> On Thu, Apr 29, 2021 at 2:51 PM krishna Ayyala >> wrote: >> >>> Hello, >>> I have a circle in which there are randomly distributed points as below. >>> Each point is a customer. >>> >>> [image: image.png] >>> >>> >>> Is there a tool within QGIS that can automatically generate four >>> polygons or four ellipses such as below. These polygons are the areas of >>> maximum concentration of the customers? >>> >>> [image: image.png] >>> >>> You could try k-means clustering >> >> >> https://docs.qgis.org/3.4/en/docs/user_manual/processing_algs/qgis/vectoranalysis.html#k-means-clustering >> >> -- >> Chris Hermansen · clhermansen "at" gmail "dot" com >> >> C'est ma façon de parler. >> > ___ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Draw Ellipse/Polygons for areas of maximum concentration
Chris, Thanks for the reply. Yes, I did run k-means clustering for 4 clusters. It is creating a new layer called "clusters". This layer has a field called Cluster_id, ranging from 1 to 4. But, this method is considering all the points within the circle. I am looking for the points outside the ellipses to be omitted (should not be considered). Also K-means clustering is not generating any polygons/ellipses. We have to identify a cluster based on the Cluster_ID. I am curious if there is any tool within Qgis that can produce results similar to the circle with ellipses? Regards. On Thu, Apr 29, 2021 at 3:56 PM chris hermansen wrote: > Krishna and list, > > On Thu, Apr 29, 2021 at 2:51 PM krishna Ayyala > wrote: > >> Hello, >> I have a circle in which there are randomly distributed points as below. >> Each point is a customer. >> >> [image: image.png] >> >> >> Is there a tool within QGIS that can automatically generate four polygons >> or four ellipses such as below. These polygons are the areas of maximum >> concentration of the customers? >> >> [image: image.png] >> >> You could try k-means clustering > > > https://docs.qgis.org/3.4/en/docs/user_manual/processing_algs/qgis/vectoranalysis.html#k-means-clustering > > -- > Chris Hermansen · clhermansen "at" gmail "dot" com > > C'est ma façon de parler. > ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Draw Ellipse/Polygons for areas of maximum concentration
Krishna and list, On Thu, Apr 29, 2021 at 2:51 PM krishna Ayyala wrote: > Hello, > I have a circle in which there are randomly distributed points as below. > Each point is a customer. > > [image: image.png] > > > Is there a tool within QGIS that can automatically generate four polygons > or four ellipses such as below. These polygons are the areas of maximum > concentration of the customers? > > [image: image.png] > > You could try k-means clustering https://docs.qgis.org/3.4/en/docs/user_manual/processing_algs/qgis/vectoranalysis.html#k-means-clustering -- Chris Hermansen · clhermansen "at" gmail "dot" com C'est ma façon de parler. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
[Qgis-user] Draw Ellipse/Polygons for areas of maximum concentration
Hello, I have a circle in which there are randomly distributed points as below. Each point is a customer. [image: image.png] Is there a tool within QGIS that can automatically generate four polygons or four ellipses such as below. These polygons are the areas of maximum concentration of the customers? [image: image.png] Regards. ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
