Issue 77932

Summary: Regression Curves - force through zero
Product: General Reporter: vabijou <vabijou>
Component: chartAssignee: AOO issues mailing list <issues>
Status: CONFIRMED --- QA Contact:
Severity: Trivial    
Priority: P3 CC: issues, rb.henschel, stefan.weigel, tony.galmiche.ooo
Version: 3.3.0 or older (OOo)Keywords: ms_interoperability, oooqa
Target Milestone: ---   
Hardware: PC   
OS: Windows XP   
Issue Type: ENHANCEMENT Latest Confirmation in: ---
Developer Difficulty: ---
Issue Depends on:    
Issue Blocks: 15522    

Description vabijou 2007-05-30 12:30:55 UTC
When adding a regression curve to data in a chart, there does not appear to be 
any way to force the curves to run through the origin.  Sometimes you want your 
your curve to be a true best fit, but sometimes you want the curve to intersect 
the origin, especially when performing a regression on a set of data from a 
physical system that theoretically should pass through the origin.
Comment 1 Regina Henschel 2007-05-30 13:49:07 UTC
For linear regression it is in issue 34093. Do you think of other types beyond
linear?
Comment 2 vabijou 2007-05-30 20:59:00 UTC
Yes, forcing the y-axis intercept to zero is applicable exponential curves as 
well as the polynomial regression I proposed in Issue 77930.
Comment 3 Regina Henschel 2007-05-30 21:16:01 UTC
Forcing to zero makes no sense for me for exponential curves. But if we get
polynomial regressions, it might be a useful feature.
Comment 4 Regina Henschel 2007-05-30 21:17:53 UTC
Hope, it goes to chart now.
Comment 5 vabijou 2007-05-30 23:53:59 UTC
I am sorry.  You are correct about forcing to zero not making sense for 
exponential curves.  However, Excel allows the user to force exponential curves 
through values greater than zero, so including that option in Chart would be 
appropriate.
Comment 6 kla 2007-05-31 15:16:21 UTC
@Iha: maybe a good idea.
Comment 7 paul8paul 2008-07-03 13:18:13 UTC
I agree.  This is very important function for me as a science student. I can't
stop using Microsoft Office until I can do this in Open Office - at least for
linear regression.  In fact in the interest of flexibility I think you should be
able to choose exactly where it intersects either axis.

I know there are scientific arguments for and against this function but what
difference does it make who is scientifically right or wrong.  If this is a
function that users want to use then Open Office should be able to do it as
simply and quickly as possible.
Comment 8 paul8paul 2008-07-03 13:25:42 UTC
Its also necessary to be able to extrapolate the line as much as desired in
either direction.