Bug 126441 - 1. Spreadsheet chart cannot draw trendline correctly
Summary: 1. Spreadsheet chart cannot draw trendline correctly
Status: RESOLVED INSUFFICIENTDATA
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Calc (show other bugs)
Version:
(earliest affected)
6.2.5.2 release
Hardware: All Linux (All)
: medium normal
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2019-07-17 12:51 UTC by MD
Modified: 2021-06-05 04:27 UTC (History)
5 users (show)

See Also:
Crash report or crash signature:


Attachments
ods spreadsheet showing faulty chart (17.01 KB, application/vnd.oasis.opendocument.spreadsheet)
2019-07-17 12:55 UTC, MD
Details
copy of original example sheet with chart showing how trend lines should look (17.01 KB, application/vnd.oasis.opendocument.spreadsheet)
2020-05-13 00:18 UTC, MD
Details
How it looks in LibreOffice 4.4 (41.73 KB, image/png)
2020-05-13 10:38 UTC, Xisco Faulí
Details

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Description MD 2019-07-17 12:51:03 UTC
Description:
XY Chart has two sets of x,y data. 3 points in each set.
The x data in each set is different.
One set was use to create the chart. 
The second set was added by editing the data series.
A trend line was added to each set.
The trend line is shown incorrectly for the second set - It does not pass through all the points.

Actual Results:
a line drawn between 2 points

Expected Results:
A line drawn through all 3 points


Reproducible: Always


User Profile Reset: No



Additional Info:
[Information automatically included from LibreOffice]
Locale: en-US
Module: SpreadsheetDocument
[Information guessed from browser]
OS: Linux (All)
OS is 64bit: yes

Version: 6.2.5.2
Build ID: 1ec314fa52f458adc18c4f025c545a4e8b22c159
CPU threads: 4; OS: Linux 4.4; UI render: default; VCL: gtk3;
Comment 1 MD 2019-07-17 12:55:31 UTC
Created attachment 152831 [details]
ods spreadsheet showing faulty chart
Comment 2 Gregor 2019-08-03 09:51:38 UTC
I believe the problem is in the second data set. Calc draws a regression line from the point with lowest x to the highest x, but because of the scale it looks faulty. Try plotting the second set only for explanation




Version: 6.2.5.2 (x64)
Build ID: 1ec314fa52f458adc18c4f025c545a4e8b22c159
CPU threads: 4; OS: Windows 10.0; UI render: GL; VCL: win; 
Locale: en-GB (sl_SI); UI-Language: en-GB
Calc: threaded
Comment 3 MD 2019-08-06 16:08:49 UTC
I modified the upper and lower limits on the x axis to zoom in on the problem data. When you do that the line is drawn correctly. 6.7735 to 6.7745

It looks like the line is drawn incorrectly at a larger scale. 
connecting the 1st and third points. This looks very obvious when the scale limits are 6.772 to 6.777
Comment 4 Timur 2020-02-05 08:02:20 UTC
This is still Unconfirmed, although I understand that Gregor reproduced, so it was supposed to mark New and set as All OS in Hardware. 
I kindly ask both to test with fresh LO master from https://dev-builds.libreoffice.org/daily/master/ (installed separately).
Comment 5 Buovjaga 2020-05-09 11:15:32 UTC
Can you include screenshots of the correct and incorrect results, so we can confirm even if we do not understand anything about trendlines?
Comment 6 MD 2020-05-13 00:18:48 UTC
Created attachment 160736 [details]
copy of original example sheet with chart showing how trend lines should look

attached a copy of original example sheet with chart showing how trend lines should look
Comment 7 QA Administrators 2020-05-13 03:51:46 UTC Comment hidden (obsolete)
Comment 8 Xisco Faulí 2020-05-13 10:38:18 UTC
Hello MD,
Was the trendline drawn correctly for you with older versions of LibreOffice?
I've tried with 

Version 4.1.0.0.alpha0+ (Build ID: efca6f15609322f62a35619619a6d5fe5c9bd5a)

and the line is not even displayed
Comment 9 Xisco Faulí 2020-05-13 10:38:41 UTC
Created attachment 160746 [details]
How it looks in LibreOffice 4.4
Comment 10 QA Administrators 2021-05-05 03:45:57 UTC Comment hidden (obsolete)
Comment 11 QA Administrators 2021-06-05 04:27:27 UTC
Dear MD,

Please read this message in its entirety before proceeding.

Your bug report is being closed as INSUFFICIENTDATA due to inactivity and
a lack of information which is needed in order to accurately
reproduce and confirm the problem. We encourage you to retest
your bug against the latest release. If the issue is still
present in the latest stable release, we need the following
information (please ignore any that you've already provided):

a) Provide details of your system including your operating
   system and the latest version of LibreOffice that you have
   confirmed the bug to be present

b) Provide easy to reproduce steps – the simpler the better

c) Provide any test case(s) which will help us confirm the problem

d) Provide screenshots of the problem if you think it might help

e) Read all comments and provide any requested information

Once all of this is done, please set the bug back to UNCONFIRMED
and we will attempt to reproduce the issue. Please do not:

a) respond via email 

b) update the version field in the bug or any of the other details
   on the top section of our bug tracker

Warm Regards,
QA Team

MassPing-NeedInfo-FollowUp