Issue 91617 - Calc chart could not perform exponential regression correctly
Summary: Calc chart could not perform exponential regression correctly
Status: CLOSED IRREPRODUCIBLE
Alias: None
Product: General
Classification: Code
Component: chart (show other issues)
Version: 3.3.0 or older (OOo)
Hardware: All All
: P3 Trivial (vote)
Target Milestone: ---
Assignee: kla
QA Contact: issues@graphics
URL:
Keywords: oooqa
Depends on:
Blocks:
 
Reported: 2008-07-13 18:38 UTC by nimit
Modified: 2013-02-24 21:19 UTC (History)
3 users (show)

See Also:
Issue Type: DEFECT
Latest Confirmation in: ---
Developer Difficulty: ---

Attachments
Data example for exponential regression (18.53 KB, application/vnd.oasis.opendocument.spreadsheet)
2008-07-16 22:52 UTC, nimit 		no flags Details
same example but with trend line (21.20 KB, application/vnd.oasis.opendocument.spreadsheet)
2008-07-17 00:28 UTC, Regina Henschel 		no flags Details
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Description nimit 2008-07-13 18:38:52 UTC 
In performing chart exponential regression, calc gives a correct trend line 
but only in a linearized power equation form. I cannot set (or plot) it to 
show trend equation in exponential form.
Comment 1 frank 2008-07-14 08:57:46 UTC 
wrong component, changed to Chart and re-assigned
Comment 2 Stefan Weigel 2008-07-15 15:47:11 UTC 
I can not reproduce your observation. Can you please give an example in a
spreadsheet document?
Comment 3 nimit 2008-07-16 22:52:04 UTC 
Created attachment 55159 [details]
Data example for exponential regression
Comment 4 nimit 2008-07-16 22:57:59 UTC 
Hello sweigel ,

I have attached a spreadsheet that contains x-y data (in an exponential 
trend). Please try to fit this curve. What I want to do is that I want a chart 
with an expoential trend and a regression line/equation passing through as 
many datapoints as possible. When I tried to do that ods gave a straight trend 
line passing through few data points. 

Should I did something wrong and the program has no defect on this please let 
me know how to do it correctly.

Thanks,
Nimit
Comment 5 Regina Henschel 2008-07-17 00:27:06 UTC 
I cannot confirm it. Doubleclick the chart > Insert > Statistic. From the
"regression"-pictures choose 'Exponential Regression' which is forth, count from
left. I'll attach your document including trend line.

Do you use an original OOo version?

You cannot determine how accuracy a trend line is by counting how many points it
hits. In most cases it will not hit any of the data points.

You should try OOo3.0 beta. There you get the equation in addition.
Comment 6 Regina Henschel 2008-07-17 00:28:11 UTC 
Created attachment 55160 [details]
same example but with trend line
Comment 7 Stefan Weigel 2008-07-17 05:38:14 UTC 
Please note: regression curve (trend line) and showing it´s equation both is
possible with OOo 2.4 as well as OOo 3.0

The difference between 2.4 and 3.0 is only the user interface.
Comment 8 kla 2008-07-22 07:45:42 UTC 
As regina has written and the attached doc shows, it works fine. So i will close
this issue.