Re: [jira] [Created] (MAHOUT-1298) SparseRowMatrix,SparseColMatrix: optimize transpose()
+1, we have type conversion anyway. On 29/07/2013 6:40 PM, Sebastian Schelter wrote: +1 2013/7/29 Dmitriy Lyubimov (JIRA) Dmitriy Lyubimov created MAHOUT-1298: Summary: SparseRowMatrix,SparseColMatrix: optimize transpose() Key: MAHOUT-1298 URL: https://issues.apache.org/jira/browse/MAHOUT-1298 Project: Mahout Issue Type: New Feature Components: Math Affects Versions: 0.8 Reporter: Dmitriy Lyubimov Assignee: Dmitriy Lyubimov Fix For: 0.9 these matrices lack optimized transpose and rely onto AbstractMatrix's O(mn) implementation which is not cool for very sparse subblocks. proposal is to implement a custom transpose with two things in mind: 1) transpose result to row sparse matrix should be col sparse matrix, and vice versa (and not from default like() as default implementation would take); 2) obviously, iterate only thru non-zero elements only of all rows(columns). -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
Re: [jira] [Created] (MAHOUT-1298) SparseRowMatrix,SparseColMatrix: optimize transpose()
+1 2013/7/29 Dmitriy Lyubimov (JIRA) > Dmitriy Lyubimov created MAHOUT-1298: > > > Summary: SparseRowMatrix,SparseColMatrix: optimize transpose() > Key: MAHOUT-1298 > URL: https://issues.apache.org/jira/browse/MAHOUT-1298 > Project: Mahout > Issue Type: New Feature > Components: Math > Affects Versions: 0.8 > Reporter: Dmitriy Lyubimov > Assignee: Dmitriy Lyubimov > Fix For: 0.9 > > > these matrices lack optimized transpose and rely onto AbstractMatrix's > O(mn) implementation which is not cool for very sparse subblocks. > > proposal is to implement a custom transpose with two things in mind: > > 1) transpose result to row sparse matrix should be col sparse matrix, and > vice versa (and not from default like() as default implementation would > take); > > 2) obviously, iterate only thru non-zero elements only of all > rows(columns). > > -- > This message is automatically generated by JIRA. > If you think it was sent incorrectly, please contact your JIRA > administrators > For more information on JIRA, see: http://www.atlassian.com/software/jira >
[jira] [Created] (MAHOUT-1298) SparseRowMatrix,SparseColMatrix: optimize transpose()
Dmitriy Lyubimov created MAHOUT-1298: Summary: SparseRowMatrix,SparseColMatrix: optimize transpose() Key: MAHOUT-1298 URL: https://issues.apache.org/jira/browse/MAHOUT-1298 Project: Mahout Issue Type: New Feature Components: Math Affects Versions: 0.8 Reporter: Dmitriy Lyubimov Assignee: Dmitriy Lyubimov Fix For: 0.9 these matrices lack optimized transpose and rely onto AbstractMatrix's O(mn) implementation which is not cool for very sparse subblocks. proposal is to implement a custom transpose with two things in mind: 1) transpose result to row sparse matrix should be col sparse matrix, and vice versa (and not from default like() as default implementation would take); 2) obviously, iterate only thru non-zero elements only of all rows(columns). -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
