commons-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From sebb <seb...@gmail.com>
Subject Re: svn commit: r1060917 - /commons/proper/math/branches/MATH_2_X/src/main/java/org/apache/commons/math/util/FastMath.java
Date Thu, 20 Jan 2011 01:20:54 GMT
On 20 January 2011 01:16, Mikkel Meyer Andersen <mikl@mikl.dk> wrote:
> Hi,
>
> Just a quick question: when a == 0.0f or NA, then a is returned. Why not
> just put a special isNA() in the beginning and 0.0f in the existing code?

Because we want to return -0.0 if a == -0.0 and +0.0 if a == +0.0

> Wouldn't it save a tiny bit not loading a?
>
> Cheers, Mikkel.
> Den 19/01/2011 20.26 skrev <sebb@apache.org>:
>> Author: sebb
>> Date: Wed Jan 19 19:26:19 2011
>> New Revision: 1060917
>>
>> URL: http://svn.apache.org/viewvc?rev=1060917&view=rev
>> Log:
>> MATH-478 FastMath is not an exact replacement for StrictMath
>> Add signum(float)
>>
>> Modified:
>>
> commons/proper/math/branches/MATH_2_X/src/main/java/org/apache/commons/math/util/FastMath.java
>>
>> Modified:
> commons/proper/math/branches/MATH_2_X/src/main/java/org/apache/commons/math/util/FastMath.java
>> URL:
> http://svn.apache.org/viewvc/commons/proper/math/branches/MATH_2_X/src/main/java/org/apache/commons/math/util/FastMath.java?rev=1060917&r1=1060916&r2=1060917&view=diff
>>
> ==============================================================================
>> ---
> commons/proper/math/branches/MATH_2_X/src/main/java/org/apache/commons/math/util/FastMath.java
> (original)
>> +++
> commons/proper/math/branches/MATH_2_X/src/main/java/org/apache/commons/math/util/FastMath.java
> Wed Jan 19 19:26:19 2011
>> @@ -582,6 +582,15 @@ public class FastMath {
>> return (a < 0.0) ? -1.0 : ((a > 0.0) ? 1.0 : a);
>> }
>>
>> + /** Compute the signum of a number.
>> + * The signum is -1 for negative numbers, +1 for positive numbers and 0
> otherwise
>> + * @param a number on which evaluation is done
>> + * @return -1, 0, +1 or NaN depending on sign of a
>> + */
>> + public static float signum(final float a) {
>> + return (a < 0.0f) ? -1.0f : ((a > 0.0f) ? 1.0f : a);
>> + }
>> +
>> /** Compute next number towards positive infinity.
>> * @param a number to which neighbor should be computed
>> * @return neighbor of a towards positive infinity
>>
>>
>

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@commons.apache.org
For additional commands, e-mail: dev-help@commons.apache.org


Mime
View raw message