Le 15/03/2013 21:21, Becksfort, Jared a écrit :
> 
> 
> -----Original Message----- From: Becksfort, Jared Sent: Monday, March
> 11, 2013 12:28 PM To: Commons Developers List Subject: RE: [math]
> Scaling arrays. .
> 
> On 3/11/13 8:21 AM, Becksfort, Jared wrote:
>> Hi Phil,
>> 
>>> What exactly *is* it and what are the use cases?
>> Just a method to multiply each element in an array by a number and
>> return either a copy of the array or do it in place.  Maybe there
>> can be one method for either way:
>> 
>> public static double[] scale(double val, final double[] arr) { 
>> double[] newArr = new double[arr.length]; for (int i = 0; i <
>> arr.length; i++) { newArr[i] = arr[i] * val; } return newArr; }
>> 
>> public static void scaleInPlace(double val, final double[] arr) { 
>> for (int i = 0; i < arr.length; i++) { arr[i] *= val; } }
>> 
>>> ...use cases
>> I imagine they are pretty varied.  These methods could be used any
>> time you want to multiply all elements in an array by a number
>> without writing a loop each time.  I am using this in some
>> optimization code that I am submitting but figured it would be
>> broadly applicable enough to just be put in the MathArrays class.
>> 
>> Jared
>> 
>> -----Original Message----- From: Phil Steitz
>> [mailto:phil.ste...@gmail.com] Sent: Sunday, March 10, 2013 2:19
>> PM To: Commons Developers List Subject: Re: [math] Scaling arrays.
>> .
>> 
>> On 3/8/13 12:14 PM, Becksfort, Jared wrote:
>>> Hello,
>>> 
>>> I may be missing it somewhere, but I am surprised there is no
>>> function for scaling arrays in MathArrays.java or somewhere
>>> else.
>>> 
>>> -          Am I stupidly missing it?
>> Probably not.  Closest thing is probably normalize in MathArrays.
>>> -          Is there a reason it is not in there?
>> Probably no; though you will find that most vector / array
>> algebraic operations are implemented on the objects in the linear
>> package, rather than directly on double[]s.
>>> -          Shall I add it?
> 
>> +1 to add this
> 
>> Created an issue and submitted patches for MathArrays.java and
>> MathArraysTest.java
> 
>> https://issues.apache.org/jira/browse/MATH-946
> 
>> Jared
> 
>> Phil What exactly *is* it and what are the use cases?
>> 
>> Phil
>>> Thanks, Jared
> 
> Hello,
> 

Hi Jared,

> Does anyone know if these changes might be committed to the
> repository?  Some upcoming changes I am submitting for another issue
> rely on it.  It is not too much trouble for me to remove the
> dependencies, but if this is going in then I may as well use it.

I will look at this tomorrow morning (European time) and will probably
commit it if nobody does it before.

best regards,
Luc

> 
> https://issues.apache.org/jira/browse/MATH-946
> 
> Thanks, Jared
> 
> 
> 
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