[jira] Issue Comment Edited: (MAHOUT-45) Matrix QR decomposition

["Sergey Chickin (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/MAHOUT-45?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12591245#action_12591245 ] 

corr edited comment on MAHOUT-45 at 4/22/08 3:50 AM:
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Seems like Givens rotations can be easily parallelized cause each rotation affects only 2 rows. Should I try implementing it for Hadoop? It could be useful for huge matrices

Givens rotations are not more difficult to implement than Gram-Schmidt. I've just implemented it and it seems to get more accurate values than Gram-Schmidt. Still, what is the best practice to calculate Q matrix? From A=QR?

      was (Author: corr):
    Seems like Givens rotations can be easily parallelized cause each rotation affects only 2 rows. Should I try implementing it for Hadoop? It could be useful for huge matrices
  
> Matrix QR decomposition
> -----------------------
>
>                 Key: MAHOUT-45
>                 URL: https://issues.apache.org/jira/browse/MAHOUT-45
>             Project: Mahout
>          Issue Type: Improvement
>          Components: Matrix
>            Reporter: Sergey Chickin
>            Priority: Minor
>         Attachments: MAHOUT-45.patch
>
>
> Matrix QR decomposition and appropriate determinant calculator

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