Rectangular artifact when visualizing in 3D

nbfazel · March 17, 2014, 3:58pm

I see what seems like a rectangular artifact when visualizing positions of particles emerging from a target in 3D using ntuple->Draw(“x:y:z”). This feature doesn’t exist in the geometry of the simulation (20 MeV electrons scattering in thin layers of Mylar, phosphor, and ferrite) and doesn’t show up in the 2D visualization of the data using using ntuple->Draw(“x:y”).

I have attached a 4-panel image to show this. (I have used the same mm scale for all axes). The top rows show 2D data (original and magnified), where the position data have circular symmetry as expected and there is no rectangular feature. The bottom row show same data in 3D from 2 different angles. There is a feature which is 80 mm in extent in the X direction which doesn’t appear in the 2D data.

Where is this coming from?

Thank you for helping out.

Neil

Root commands used to create the atached images:

root [0] TFile f(“geant4_output_4_9_6_electron.root”)
root [1] c1=new TCanvas(“c1”, “geant4.9.6”)
root [11] c1->Divide(2,2)
root [12] c1->cd(1)
root [13] ntuple->Draw(“x:y”)
root [14] c1->cd(2)
root [15] ntuple->Draw(“x:y”,“x>-5 && x<5 && y>-5 && y<5”)
root [16] c1->cd(3)
root [17] ntuple->Draw(“x:y:z”)
root [18] c1->cd(4)
root [19] ntuple->Draw(“x:y:z”)
root [23] c1->SaveAs(“geant4.9.6_2D_vs_3D_4panels.png”)

couet · March 18, 2014, 8:31am

Can you provide an example ?

nbfazel · March 19, 2014, 3:35pm

An example in addition to the images I attached?
Did you mean the data used to create the images?

Neil

couet · March 19, 2014, 3:44pm

Yes, if possible. Or a subset reproducing this behavior.
We need them to understand from where the artefact is coming from.

nbfazel · March 19, 2014, 3:58pm

[quote=“couet”][quote]
Did you mean the data used to create the images?
[/quote]

Yes, if possible. Or a subset reproducing this behavior.
We need them to understand from where the artefact is coming from.[/quote]

Thanks. I have uploaded the .root file to my DropBox, and here’s the link for it:

dropbox.com/s/pohp4q7ctr4kv … ctron.root

Neil

couet · March 19, 2014, 4:05pm

Thanks,
I see the problem… I need time to investigate … Right now I have no idea where that come from

nbfazel · March 19, 2014, 4:30pm

[quote=“couet”]Thanks,
I see the problem… I need time to investigate … Right now I have no idea where that come from[/quote]

OK, thanks.

couet · March 19, 2014, 4:33pm

I have changed the marker type and the color of the markers
As you see it looks like something is plotted in addition.
It is a bug a TTree:Draw. We will investigate.

couet · March 20, 2014, 2:51pm

This bug is now fixed in 5.34-patches and in ROOT trunk.
Thanks for reporting.

nbfazel · March 20, 2014, 3:35pm

[quote=“couet”]This bug is now fixed in 5.34-patches and in ROOT trunk.
Thanks for reporting.[/quote]

Thanks very much!

nbfazel · April 2, 2014, 8:39pm

Has the new patch bundle with this patch included been released? We updated to ROOT 5.34, and apparently this is not included, according to our IT support. Could you please confirm that this has been released?

Thanks,
Neil

betterwang · April 2, 2014, 9:05pm

Has the new patch bundle with this patch included been released? We updated to ROOT 5.34, and apparently this is not included, according to our IT support. Could you please confirm that this has been released?

Thanks,
Neil[/quote]
I think he meant the fix is in the git repo.
You can either compile from the HEAD, or wait for the next release.

Cheers,

nbfazel · April 2, 2014, 9:46pm

Has the new patch bundle with this patch included been released? We updated to ROOT 5.34, and apparently this is not included, according to our IT support. Could you please confirm that this has been released?[/quote]
I think he meant the fix is in the git repo. You can either compile from the HEAD, or wait for the next release.[/quote]
Thanks. Is there a way to find out when the next release will be?

Neil

couet · April 3, 2014, 7:15am

You can get the 5.34 patches version from the root web site

nbfazel · April 3, 2014, 12:59pm

This is what the IT staff here told me (grad students can’t download software directly):

“as far as I can tell they’ve not yet released the new patch bundle with your patch included. So I would have to try to pull it out of their repository and manually include it.”

Does this make sense?

Thanks,
Neil

couet · April 3, 2014, 1:28pm

You can follow the the release here:
root.cern.ch/drupal/content/root … ease-notes
the last one was march 14
the patch I did was march 20
so it is in patches now … not in a stamped 5.34 version

nbfazel · April 3, 2014, 5:08pm

[quote=“couet”]You can follow the the release here:
root.cern.ch/drupal/content/root … ease-notes
the last one was march 14
the patch I did was march 20
so it is in patches now … not in a stamped 5.34 version[/quote]
Thanks for the info.