vertex indices missing after simplification

[kamakshidasan]

hi,

I'm currently using TTK's master branch for running experiments. I perform the same tasks as issue #126

There, you can verify that for all the nodes of the split tree, there exists
a unique corresponding point in the diagram such that:

• the PointData field "VertexId" of the split tree equals the PointData
  field "VertexIdentifier" in the diagram

I cannot verify the above statement. There are vertex indices that are present in the contour tree as nodes but not present in the thresholded persistent diagram. I'm attaching a screenshot and the state file.

bug.pvsm.zip

Cheers,

Adhitya

[julien-tierny]

hi, can you please provide the file "tv_1.vtk" mentioned in your state file. thanks -- Dr Julien Tierny CNRS Researcher Sorbonne Universite http://lip6.fr/Julien.Tierny

…

On Saturday, July 7, 2018 8:30:14 PM CEST Kamakshidasan wrote: hi, I'm currently using TTK's master branch for running experiments. I perform the same tasks as issue #126 > There, you can verify that for all the nodes of the split tree, there > exists a unique corresponding point in the diagram such that: > - the PointData field "VertexId" of the split tree equals the PointData > field "VertexIdentifier" in the diagram I cannot verify the above statement. There are vertex indices that are present in the contour tree as nodes but not present in the thresholded persistent diagram. I'm attaching a screenshot and the state file. <img width="1440" alt="missing-issue" src="https://user-images.githubusercontent.com/9362064/42413618-4a4710c8-82 24-11e8-8b8e-3ca196d7e265.png"> [bug.pvsm.zip](https://github.com/topology-tool-kit/ttk/files/2172991/bug.pv sm.zip) Cheers, Adhitya

[kamakshidasan]

Sorry about that. Here you go.

tv_1.vtk.zip

[julien-tierny]

hi, there's a mismatch indeed for a few of them. the mismatches seem to involve boundary saddles which are not constrained by the algorithm. a work around would consist in computing a second persistence diagram after the topological simplification, there you should have the fixed matching by construction (which seems to do the trick here). thanks for letting us know if that fixes your issue. best, -- Dr Julien Tierny CNRS Researcher Sorbonne Universite http://lip6.fr/Julien.Tierny

…

On Saturday, July 7, 2018 8:51:54 PM CEST Kamakshidasan wrote: Sorry about that. Here you go. [tv_1.vtk.zip](https://github.com/topology-tool-kit/ttk/files/2173004/tv_1.v tk.zip)

[kamakshidasan]

there's a mismatch indeed for a few of them.

the mismatches seem to involve boundary saddles which are not constrained by

the algorithm.

Thanks for acknowledging this. Will this be fixed in the future? a work around would consist in computing a second persistence

diagram after the topological simplification, there you should have the fixed matching by construction (which seems to do the trick here).

This is exactly the work around I use as well! On Sat, Jul 7, 2018 at 9:23 PM, Julien Tierny <notifications@github.com> wrote:

…

hi, there's a mismatch indeed for a few of them. the mismatches seem to involve boundary saddles which are not constrained by the algorithm. a work around would consist in computing a second persistence diagram after the topological simplification, there you should have the fixed matching by construction (which seems to do the trick here). thanks for letting us know if that fixes your issue. best, -- Dr Julien Tierny CNRS Researcher Sorbonne Universite http://lip6.fr/Julien.Tierny On Saturday, July 7, 2018 8:51:54 PM CEST Kamakshidasan wrote: > Sorry about that. Here you go. > > > [tv_1.vtk.zip](https://github.com/topology-tool-kit/ttk/ files/2173004/tv_1.v > tk.zip) — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#130 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AI7akLRqcCouynIrsVyON14JU9q4RKPkks5uEQqmgaJpZM4VGc3C> .

[julien-tierny]

Will this be fixed in the future?

if you come up with an algorithm that enforces constraints on boundary saddles and you're willing to share its implementation, then probably :)

This is exactly the work around I use as well!

good. I'll go ahead and close this one then. best, -- Dr Julien Tierny CNRS Researcher Sorbonne Universite http://lip6.fr/Julien.Tierny

…

On Saturday, July 7, 2018 9:26:58 PM CEST Kamakshidasan wrote: > there's a mismatch indeed for a few of them. the mismatches seem to involve boundary saddles which are not constrained by > the algorithm. Thanks for acknowledging this. Will this be fixed in the future? a work around would consist in computing a second persistence > diagram after the topological simplification, there you should have the > fixed > matching by construction (which seems to do the trick here). This is exactly the work around I use as well! On Sat, Jul 7, 2018 at 9:23 PM, Julien Tierny ***@***.***> wrote: > hi, > there's a mismatch indeed for a few of them. > the mismatches seem to involve boundary saddles which are not constrained > by > the algorithm. a work around would consist in computing a second > persistence > diagram after the topological simplification, there you should have the > fixed > matching by construction (which seems to do the trick here). > thanks for letting us know if that fixes your issue. > best, > -- > Dr Julien Tierny > CNRS Researcher > Sorbonne Universite > http://lip6.fr/Julien.Tierny > > On Saturday, July 7, 2018 8:51:54 PM CEST Kamakshidasan wrote: > > Sorry about that. Here you go. > > > > > > [tv_1.vtk.zip](https://github.com/topology-tool-kit/ttk/ > > files/2173004/tv_1.v > > > tk.zip) > > — > You are receiving this because you authored the thread. > Reply to this email directly, view it on GitHub > <#130 (comment) > 7>, or mute the thread > <https://github.com/notifications/unsubscribe-auth/AI7akLRqcCouynIrsVyON14 > JU9q4RKPkks5uEQqmgaJpZM4VGc3C> .