Bug 188617

Summary:	Substraction gives erroneous result
Product:	[Plasma] krunner	Reporter:	Hervé Fache <herve>
Component:	general	Assignee:	Plasma Bugs List <plasma-bugs>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	dominik.tritscher
Priority:	NOR
Version:	unspecified
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Hervé Fache 2009-04-01 21:14:35 UTC

Version:            (using KDE 4.2.1)
OS:                Linux
Installed from:    Ubuntu Packages

I type Alt-F2 to start krunner. Then I type my calculation: '=66.02 -25.37'
It gives me the following result: '40.64999999999999'

Same if I type '66.02 - 25.37 ='

Comment 1 Hervé Fache 2009-04-03 09:43:57 UTC

This is also the case in:
Version:            (using KDE 4.2.2)
OS:                Linux
Installed from:    Ubuntu Packages

Comment 2 Fábio Firmo 2009-04-03 23:03:19 UTC

This is a expected rounding error, due the hardware representation of real numbers. The result is the same in the python interpreter, for example.

This report can be closed, I think. A more sophisticated calculator engine can be requested by a wish.

Comment 3 Dominik Tritscher 2009-04-03 23:10:38 UTC


*** This bug has been marked as a duplicate of bug 167986 ***

Comment 4 Hervé Fache 2009-04-04 16:21:01 UTC

Fábio, rounding errors are for divisions. This is a substraction and no rounding is necessary.

This is a bug, and a big one, as can be seen in the examples in https://bugs.kde.org/show_bug.cgi?id=167986 (the original bug of which mine is a duplicate).