[ https://issues.apache.org/jira/browse/MAHOUT-945?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13201399#comment-13201399 ]
Wang Yue commented on MAHOUT-945: --------------------------------- Hi, Mukai Thanks for your efforts. I feel it is ok for your modification. I have a question about the decision tree building. Do you know the meaning of option "complementary" using mahout to build the random forest? On Mon, Jan 23, 2012 at 6:55 AM, Ikumasa Mukai (Updated) (JIRA) < -- Regards, Wang Yue PhD Starts From 08 Fall NUS Graduate School for Integrative Sciences and Engineering, NUS Email: wang...@nus.edu.sg Homepage: https://sites.google.com/site/fayue1015/ HP: +65 81022515 > The variance calculation of Random forest regression tree > --------------------------------------------------------- > > Key: MAHOUT-945 > URL: https://issues.apache.org/jira/browse/MAHOUT-945 > Project: Mahout > Issue Type: Improvement > Components: Classification > Affects Versions: 0.6 > Reporter: Wang Yue > Labels: Regressionsplit.java > Attachments: MAHOUT-945.patch, MAHOUT-945.patch > > Original Estimate: 48h > Remaining Estimate: 48h > > Hi, Mukai > Thanks for your efforts in expand the RF to regression. However, I have a > doubt about your implementation regarding to Regressionsplit.java. The > variance method > " > private static double variance(double[] s, double[] ss, double[] dataSize) { > double var = 0; > for (int i = 0; i < s.length; i++) { > if (dataSize[i] > 0) { > var += ss[i] - ((s[i] * s[i]) / dataSize[i]); > } > } > return var; > } > " > While the variance in my mind should be something like > var += ss[i]/dataSize[i] - ((s[i] * s[i]) / (dataSize[i]*dataSize[i])); > Please help correct me if I am wrong. Thanks -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira