Bug 130761

Summary:	Calc Floating point number
Product:	LibreOffice	Reporter:	Thomas <info>
Component:	Calc	Assignee:	Not Assigned <libreoffice-bugs>
Status:	CLOSED WONTFIX
Severity:	normal	CC:	info, xiscofauli
Priority:	medium
Version:	Inherited From OOo
Hardware:	All
OS:	All
Whiteboard:
Crash report or crash signature:		Regression By:
Attachments:	sample file

Description Thomas 2020-02-18 19:20:16 UTC

in A1 type 8
in A2 type =A1+0.1
copy this formula down to A3:A21, A21 then shows 10. In B21 type =ROUNDDOWN(A21). The result is 9.

Might be same problem as in id=130202, but not sure, because autofill gives other values than iterated formulas.

Comment 1 Xisco Faulí 2020-02-18 20:29:00 UTC

Created attachment 157989 [details]
sample file

Comment 2 Xisco Faulí 2020-02-18 20:30:05 UTC

I can reproduce it in

Version: 7.0.0.0.alpha0+
Build ID: 28d844a589e52abfe62dc66b888e78665221ba28
CPU threads: 4; OS: Linux 4.19; UI render: default; VCL: x11; 
Locale: en-US (en_US.UTF-8); UI-Language: en-US
Calc: threaded

and back to

LibreOffice 3.3.0 
OOO330m19 (Build:6)
tag libreoffice-3.3.0.4

Comment 3 Xisco Faulí 2020-02-18 20:35:34 UTC

I get the same result in Google Sheets, so I'm wondering if 9 is the correct result.
What would be the expected result for you ?

Comment 4 Eike Rathke 2020-02-18 20:53:14 UTC

As usual. Adding floating point 0.1 repeatedly gives inaccurate results as 0.1 is not precisely representable as IEEE 754 double. Don't do that.

If you're interested in details for why 0.1 + 0.2 ≠ 0.3 see links under
https://erack.de/bookmarks/D.html#010203