[ 
https://issues.apache.org/jira/browse/MAHOUT-1729?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Dmitriy Lyubimov updated MAHOUT-1729:
-------------------------------------
    Description: 
SparseMatrix in particular does iterateNonEmpty() instead of iterating over all 
rows in default iterator. This creates contract inconsistency leading to 
computational errors.

so... this fixes to guarantee that 

for (row <- mxA)  

visits ALL rows in the mxA (even if they are totally empty). 

If it is ok not to process completely 0ed rows, then the following form should 
be used: 

for (row <- mxA.iterateNonEmpty) ... 

PR https://github.com/apache/mahout/pull/135


  was:
SparseMatrix in particular does iterateNonEmpty() instead of iterating over all 
rows in default iterator. This creates contract inconsistency leading to 
computational errors.

so... this fixes to guarantee that 

for (row <- mxA)  

visits ALL rows in the mxA (even if they are totally empty). 

If it is ok not to process completely 0ed rows, then the following form should 
be used: 

for (row <- mxA.iterateNonEmpty) ... 



> Straighten out behavior of Matrix.iterator() and iterateNonEmpty()
> ------------------------------------------------------------------
>
>                 Key: MAHOUT-1729
>                 URL: https://issues.apache.org/jira/browse/MAHOUT-1729
>             Project: Mahout
>          Issue Type: Bug
>            Reporter: Dmitriy Lyubimov
>            Assignee: Dmitriy Lyubimov
>             Fix For: 0.10.2
>
>
> SparseMatrix in particular does iterateNonEmpty() instead of iterating over 
> all rows in default iterator. This creates contract inconsistency leading to 
> computational errors.
> so... this fixes to guarantee that 
> for (row <- mxA)  
> visits ALL rows in the mxA (even if they are totally empty). 
> If it is ok not to process completely 0ed rows, then the following form 
> should be used: 
> for (row <- mxA.iterateNonEmpty) ... 
> PR https://github.com/apache/mahout/pull/135



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to