commons-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Mark R. Diggory" <mdigg...@latte.harvard.edu>
Subject Re: [math] UnivariateImpl - when sumsq ~ xbar*xbar*((double) n)
Date Tue, 03 Jun 2003 19:00:52 GMT
Yes, I'm working my way through all the bug patches and trying apply 
them in order. Hopefully this shouldn't take too long, but I'm in and 
out of the office today, so it might not be til this evening.

-Mark

Phil Steitz wrote:

>--- "Mark R. Diggory" <mdiggory@latte.harvard.edu> wrote:
>  
>
>>Phil Steitz wrote:
>>
>>    
>>
>>>Al Chou wrote:
>>>
>>>      
>>>
>>>>Uh, did we drop the idea of using the "corrected two-pass" algorithm 
>>>>for the
>>>>variance in the non-rolling case?  I excerpted that thread below.
>>>>        
>>>>
>>>I was going to mention that.  The discussion above regards the 
>>>"non-stored vector" approach (UnivariateImpl).  I submitted some 
>>>patches to the "stored" classes 
>>>(StoredUnivariate,AbstractStoreUnivariate) last weekend (adding 
>>>percentiles -- 
>>>http://issues.apache.org/bugzilla/show_bug.cgi?id=20377) and I was 
>>>waiting for them to get committed before suggesting this 
>>>change/submitting the patch.
>>>
>>>Given our recent NR entanglements, we need to make sure that if and 
>>>when we apply that patch we document using the original source of the 
>>>formula.
>>>
>>>Thanks for the remider.
>>>
>>>What is relevant to the UnivariateImpl computations is Brent's 
>>>suggestion re: making "running" error corrections.  Have you 
>>>investigated this further? 
>>>      
>>>
>>I'll pick up this patch and apply it before any of my changes to 
>>UnivariateImpl. Thanks for redirecting my attention to it, I'm still 
>>getting used to going into bugzilla.
>>
>>    
>>
>
>Thanks, Mark.
>
>While you're in the neighborhood, can you also commit the patch that I
>submitted adding MathUtils: 
>http://nagoya.apache.org/bugzilla/show_bug.cgi?id=20390
>
>It occurs to me now that MathUtils, a simple utility class extending the basic
>computing functions in java.lang.Math would make a nice place to encapsulate
>our array-based mean, variance and standard deviation computations, using Al's
>suggested improvements.  Users would likely find simple double[] |- > double
>functions to compute means, variances, std dev, min and max directly useful and
>the various Univariate implementations could leverage them.
>
>Phil
>  
>
>>-Mark
>>
>>
>>
>>
>>---------------------------------------------------------------------
>>To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
>>For additional commands, e-mail: commons-dev-help@jakarta.apache.org
>>
>>    
>>
>
>
>__________________________________
>Do you Yahoo!?
>Yahoo! Calendar - Free online calendar with sync to Outlook(TM).
>http://calendar.yahoo.com
>
>---------------------------------------------------------------------
>To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
>For additional commands, e-mail: commons-dev-help@jakarta.apache.org
>
>  
>



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


Mime
View raw message