Bug 231816 - with fractionary exponents sometimes the correct domain is not calculated
Summary: with fractionary exponents sometimes the correct domain is not calculated
Status: RESOLVED FIXED
Alias: None
Product: analitza
Classification: Frameworks and Libraries
Component: analitzaplot (show other bugs)
Version: unspecified
Platform: unspecified Linux
: NOR normal
Target Milestone: ---
Assignee: Aleix Pol
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2010-03-22 19:21 UTC by Riccardo Iaconelli
Modified: 2013-10-29 00:52 UTC (History)
3 users (show)

See Also:
Latest Commit:
Version Fixed In: 4.12
Sentry Crash Report:


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Description Riccardo Iaconelli 2010-03-22 19:21:40 UTC
Version:           0.9 (using 4.4.1 (KDE 4.4.1), Chakra)
Compiler:          gcc
OS:                Linux (i686) release 2.6.32-ARCH

Try to insert a function like this:

http://www.wolframalpha.com/input/?i=%282x^2-x^3%29^%281%2F3%29

KAlgebra will stop drawing it for x = 4, while the function obviously has R as domain.
Comment 1 Aleix Pol 2010-05-02 05:40:44 UTC
Well, this is happening because std::power is returning nan, I'll have to investigate better why.

Thanks for the report :)
Comment 2 Aleix Pol 2010-05-02 05:44:32 UTC
And it's returning that because there's some imaginary part, of course...

I guess we'll have to wait until we support imaginary numbers to support such
feature
Comment 3 Riccardo Iaconelli 2010-05-29 14:57:09 UTC
On Sunday 02 May 2010 05:44:32 Aleix Pol wrote:
> And it's returning that because there's some imaginary part, of course...
> 
> I guess we'll have to wait until we support imaginary numbers to support
> such feature

Well, there's ALSO an imaginary part, but not just it... So I think that at 
least that the real part should be shown... :)

Bye,
-Riccardo
Comment 4 Aleix Pol 2010-12-14 05:15:21 UTC
Still to do!
Mental note: use complex class when pow(a,b) if a<0 and b is not an integer.
Comment 5 heena 2012-12-25 17:45:30 UTC
I guess the given equation is real for x belongs to (0,2) and for [2,infinity) U (-infinity,0] It will have imaginary components as well .
Comment 6 Aleix Pol 2013-10-28 20:28:19 UTC
Git commit fde6bdfb0114d384c1ad258fd351f4558ea63e09 by Aleix Pol.
Committed on 28/10/2013 at 20:28.
Pushed by apol into branch 'master'.

Support roots with an imaginary part
Related: bug 302813

M  +7    -3    analitza/operations.cpp
M  +5    -3    analitza/tests/analitzatest.cpp

http://commits.kde.org/analitza/fde6bdfb0114d384c1ad258fd351f4558ea63e09