[ https://issues.apache.org/jira/browse/MAHOUT-300?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12836817#action_12836817 ]
Ted Dunning commented on MAHOUT-300: ------------------------------------ These are getting respectable! As a quick hack, the fact that dot is commutative should make it possible to get identical results for dense.dot(seq) as for seq.dot(dense). Likewise for dense.dot(rand). A similar, but less dramatic win might come from rnd.dot(seq) being redone as seq.dot(rnd). > Solve performance issues with Vector Implementations > ---------------------------------------------------- > > Key: MAHOUT-300 > URL: https://issues.apache.org/jira/browse/MAHOUT-300 > Project: Mahout > Issue Type: Improvement > Affects Versions: 0.3 > Reporter: Robin Anil > Fix For: 0.3 > > Attachments: MAHOUT-300.patch, MAHOUT-300.patch, MAHOUT-300.patch, > MAHOUT-300.patch, MAHOUT-300.patch, MAHOUT-300.patch, MAHOUT-300.patch, > MAHOUT-300.patch, MAHOUT-300.patch > > > AbstractVector operations like times > public Vector times(double x) { > Vector result = clone(); > Iterator<Element> iter = iterateNonZero(); > while (iter.hasNext()) { > Element element = iter.next(); > int index = element.index(); > result.setQuick(index, element.get() * x); > } > return result; > } > should be implemented as follows > public Vector times(double x) { > Vector result = clone(); > Iterator<Element> iter = result.iterateNonZero(); > while (iter.hasNext()) { > Element element = iter.next(); > element.set(element.get() * x); > } > return result; > } -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.