Bug 368697 - some float numbers raised to a power equal infinity
Summary: some float numbers raised to a power equal infinity
Status: RESOLVED UNMAINTAINED
Alias: None
Product: kcalc
Classification: Applications
Component: general (show other bugs)
Version: unspecified
Platform: RedHat Enterprise Linux Linux
: NOR major
Target Milestone: ---
Assignee: Evan Teran
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2016-09-12 14:50 UTC by Floren
Modified: 2016-09-14 16:00 UTC (History)
1 user (show)

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Description Floren 2016-09-12 14:50:44 UTC
Using Kcalc version 2.5 in KDE 4.3.4 If I raise a decimal number to a decimal power the result is sometimes infinity. For example this happens for e^8.4 or for pi^9.1. It does not happen for pi^9.0 or for 2.5^8.4.

Reproducible: Always

Steps to Reproduce:
1. Open Kcalc.
2. Load number "pi" from constants.
3. Raised the number "pi" to the power 8.4.

Actual Results:  
The result of the operation is incorrect, it gives infinity. 

Expected Results:  
I expect a final result, in particular pi^8.4 = 14998.883473768
Comment 1 Evan Teran 2016-09-12 16:41:50 UTC
I believe that this is an older version of kcalc as I cannot reproduce this on my version.

However, it it worth noting that for many floating point operations, kcalc, in its current implementation temporarily converts back and forth between the infinite precision and "long doubles" so that it can use libc's trig routines.

I would love to switch this to an infinite precision trig library (particularly MPFR is my preference), but this is not implemented yet.
Comment 2 Christoph Feck 2016-09-14 16:00:09 UTC
KDE 4.3 is long unmaintained.