Bug 57234

Summary:	Incorrect b-spline smoothing
Product:	LibreOffice	Reporter:	souradova
Component:	Chart	Assignee:	Not Assigned <libreoffice-bugs>
Status:	RESOLVED DUPLICATE
Severity:	normal
Priority:	medium
Version:	3.6.3.2 release
Hardware:	Other
OS:	All
Whiteboard:
Crash report or crash signature:		Regression By:

Description souradova 2012-11-17 21:04:43 UTC

Smoothing for XY graph is incorrect when b-spline is selected. It interpolates the data points with a polynome that goes through the points exactly which should generally not be the case for b-spline. See 

http://en.wikipedia.org/wiki/B-spline

for more info about the correct b-spline smoothing. Now it looks, on first look, more like hermitan polynome interpolation instead of B-spline smoothing.

Comment 1 Markus Mohrhard 2013-02-14 16:40:02 UTC

The B-Spline algorithm is specified by ODF 1.2 so we have to implement the algorithm mentioned there. However there is still an issue in the implementation and I was yet unable to spend enough time in fixing it.

*** This bug has been marked as a duplicate of bug 47787 ***