View Issue Details [ Jump to Notes ] [ Print ]
IDProjectCategoryView StatusDate SubmittedLast Update
0015686ParaView(No Category)public2015-08-26 11:502016-08-12 09:59
ReporterVadim SANDLER 
Assigned ToJoachim Pouderoux 
PrioritynormalSeverityminorReproducibilityhave not tried
StatusclosedResolutionmoved 
PlatformOSOS Version
Product Version4.3 
Target VersionFixed in Version 
Summary0015686: Extract bag plot filter is not using the most adequate 2D kernel density estimation.
DescriptionIn Paraview, HDR plot uses a 2D kernel density estimation in the plane associated to the first 2 principal components. In Paraview, a symmetrical normal kernel is used and its width, given by the user, is by default equal to 1. This 2D density approximation is not accurate.

In the Rainbow package, the method used is the kernel density estimation is based on a generic Gaussian not necessarily symmetrical. In addition, kernel's parameters (i.e. the covariance matrix) are determined by crosschecking (implying a optimization)

To validate this functionality, the "gaussian sine" case can be used.
TagsNo tags attached.
ProjectParaViS
Topic Name
Typeincorrect functionality
Attached Filescsv file icon gaussiansine.csv [^] (226,137 bytes) 2015-08-26 11:50

 Relationships

  Notes
(0035066)
Vadim SANDLER (reporter)
2015-08-26 12:15

 Please find more pieces of information about the reasons of the improper use of a symmetrical normal kernel in the following:

- a symmetrical kernel implies density is approximate by the kernel with the same variance in the two principal components. In general, the data variance will be different according to the direction. Indeed, the variance of the first component will be greater than the variance of the second by definition of the PCA.

- the user must choose a parameter implying that the estimation will be actually, either too large (smoothing too strong of the desnity), either too small (discontinuities in the kernel estimation).
(0035817)
Joachim Pouderoux (developer)
2016-03-03 08:42

 https://gitlab.kitware.com/paraview/paraview/merge_requests/580 [^]
(0038879)
Kitware Robot (administrator)
2016-08-12 09:59

 Resolving issue as `moved`.

This issue tracker is no longer used. Further discussion of this issue may take place in the current ParaView Issues page linked in the banner at the top of this page.

 Issue History
Date Modified Username Field Change
2015-08-26 11:50 Vadim SANDLER New Issue
2015-08-26 11:50 Vadim SANDLER File Added: gaussiansine.csv
2015-08-26 12:15 Vadim SANDLER Note Added: 0035066
2016-03-03 08:42 Joachim Pouderoux Note Added: 0035817
2016-03-03 08:42 Joachim Pouderoux Assigned To => Joachim Pouderoux
2016-03-03 08:43 Joachim Pouderoux Status backlog => active development
2016-08-12 09:59 Kitware Robot Note Added: 0038879
2016-08-12 09:59 Kitware Robot Status active development => closed
2016-08-12 09:59 Kitware Robot Resolution open => moved

Copyright © 2000 - 2018 MantisBT Team