[
https://issues.apache.org/jira/browse/MATH-314?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12804667#action_12804667
]
Ted Dunning commented on MATH-314:
----------------------------------
I just asked Jake about this off-list and his reply was that this functionality
has been incorporated in the Mahout math package. This decreased his level of
urgency below the critical level required to get a patch into good shape and he
is reluctant to give you guys an 80% done patch since it would just increase
the work for you.
> New sparse vector implementation: int[] indices; double[] values;
> -----------------------------------------------------------------
>
> Key: MATH-314
> URL: https://issues.apache.org/jira/browse/MATH-314
> Project: Commons Math
> Issue Type: New Feature
> Affects Versions: 2.0
> Environment: all
> Reporter: Jake Mannix
> Priority: Minor
> Fix For: 2.1
>
>
> OpenMapRealVector is nice for fast random access, but if all you do with your
> sparse vectors is dot them together, add them onto dense vectors, and so
> forth, the representation as just an array of indices and an array of values
> is more compact, and faster (for these operations).
> It becomes prohibitive to do modification, however, so the usual thing is to
> have them be immutable - use an OpenMapRealVector while modifing, then seal
> them up into the constructor for an IntDoubleArrayVector form for fast
> iteration and so forth.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
