United StatesChange Country, Oracle Worldwide Web Sites Communities I am a... I want to...
Bug ID: JDK-4900189 Refine spec requirements for tanh, expm1
JDK-4900189 : Refine spec requirements for tanh, expm1

Details
Type:
Bug
Submit Date:
2003-08-01
Status:
Resolved
Updated Date:
2003-08-30
Project Name:
JDK
Resolved Date:
2003-08-30
Component:
core-libs
OS:
generic
Sub-Component:
java.lang
CPU:
generic
Priority:
P4
Resolution:
Fixed
Affected Versions:
5.0
Fixed Versions:
5.0 (tiger)

Related Reports
Relates:
Relates:

Sub Tasks

Description
The math functions tanh and expm1 approach limit values for suffiently large arguments.  The specifications of those functions should impose more explic it constraints on how the limits may be approached as well as bounding the functions' results to stay within the true functions' bounds.

                                    

Comments
EVALUATION

A fine idea.

###@###.### 2003-08-01
                                     
2003-08-01
SUGGESTED FIX

src/share/classes/java/lang>sccs sccsdiff -r1.61 -r1.62 Math.java

------- Math.java -------
54,55c54,55
<  * important.  Therefore, methods with more than 0.5 ulp errors are
<  * required to be <i>semi-monotonic</i>: whenever the mathematical
---
>  * important.  Therefore, most methods with more than 0.5 ulp errors
>  * are required to be <i>semi-monotonic</i>: whenever the mathematical
1105c1105,1109
<      * result.
---
>      * result.  The result of <code>tanh</code> for any finite input
>      * must have an absolute value less than or equal to 1.  Note that
>      * once the exact result of tanh is within 1/2 of an ulp of the
>      * limit value of &plusmn;1, correctly signed
>      * &plusmn;<code>1.0</code> should be returned.
1165c1169,1174
<      * result.  Results must be semi-monotonic.
---
>      * result.  Results must be semi-monotonic.  The result of
>      * <code>expm1</code> for any finite input must be greater than or
>      * equal to <code>-1.0</code>.  Note that once the exact result of
>      * <i>e</i><sup><code>x</code></sup>&nbsp;-&nbsp;1 is within 1/2
>      * ulp of the limit value -1, <code>-1.0</code> should be
>      * returned.

###@###.### 2003-08-15
                                     
2003-08-15
CONVERTED DATA

BugTraq+ Release Management Values

COMMIT TO FIX:
tiger

FIXED IN:
tiger

INTEGRATED IN:
tiger
tiger-b18


                                     
2004-06-14



Hardware and Software, Engineered to Work Together