[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Octave-bug-tracker] [bug #56537] marcumq can return impossible values o
From: |
anonymous |
Subject: |
[Octave-bug-tracker] [bug #56537] marcumq can return impossible values or hang completely |
Date: |
Fri, 21 Jun 2019 12:25:22 -0400 (EDT) |
User-agent: |
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:67.0) Gecko/20100101 Firefox/67.0 |
URL:
<https://savannah.gnu.org/bugs/?56537>
Summary: marcumq can return impossible values or hang
completely
Project: GNU Octave
Submitted by: None
Submitted on: Fri 21 Jun 2019 04:25:20 PM UTC
Category: None
Severity: 3 - Normal
Priority: 5 - Normal
Item Group: None
Status: None
Assigned to: None
Originator Name: Jerry W. Lewis
Originator Email: address@hidden
Open/Closed: Open
Discussion Lock: Any
Release: 4.4.1
Operating System: Microsoft Windows
_______________________________________________________
Details:
The marcumq function calculates a probability and therefore should be bounded
by zero and one. However, the implementation in the Octave 4.4.1
communications package running under Windows (W10) can return Inf without
detecting any problems. Also, it can get into what appears to be an infinite
loop.
To illustrate these problems, consider the calculation
marcumq(sqrt(0.2*m), sqrt(2.1*ma), m)
implemented as an anonymous function
pkg load communications
f = @(m) marcumq(sqrt(0.2*m), sqrt(2.1*m), m)
f([1,10,100,604]) % essentially machine accuracy for m<=604
f([605,634]) % Inf with no warnings for 605<=m<=634 (should be
[0.87004,0.87573])
f(635) % Inf with warnings for 635<=m<=1033 (should be 0.87592)
f(1033) % Inf with warnings for 635<=m<=1033 (should be 0.93048)
f(1034) % hangs (infinite loop?) for m>=1034 (should be 0.93058)
_______________________________________________________
Reply to this item at:
<https://savannah.gnu.org/bugs/?56537>
_______________________________________________
Message sent via Savannah
https://savannah.gnu.org/
- [Octave-bug-tracker] [bug #56537] marcumq can return impossible values or hang completely,
anonymous <=