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From deneche abdelhakim <adene...@gmail.com>
Subject Re: Decision Forest/Partial Implementation TestForest Error
Date Sat, 08 Sep 2012 09:05:18 GMT
Could you copy/paste the exact commands you used to run the training and
the testing ?

On Fri, Sep 7, 2012 at 11:10 PM, Nick Jordan <nick@influen.se> wrote:

> Any thoughts here?
>
> On Thu, Sep 6, 2012 at 7:00 AM, Nick Jordan <nick@influen.se> wrote:
> > Same problem with the sequential classifier.  My guess is that this
> > "corruption" is happening because of that particular setting as it is
> > the only thing that I'm changing, but I have no idea how to
> > investigate further.
> >
> > Nick
> >
> > On Thu, Sep 6, 2012 at 2:22 AM, Abdelhakim Deneche <adeneche@gmail.com>
> wrote:
> >> Hi Nick,
> >>
> >> This is not a memory problem, the classifier tries to load the trained
> forest but it's getting some unexpected values. This problem never occured
> before! Could the forest files be corrupted ?
> >>
> >> Try training the forest once again, and this time use the sequential
> classifier (don't use the -mr parameter) and see if the problem still
> occurs.
> >>
> >>
> >> On 5 sept. 2012, at 23:00, Nick Jordan <nick@influen.se> wrote:
> >>
> >>> Hello All,
> >>>
> >>> I'm playing around with decision forests using the partial
> >>> implementation and my own data set.  I am getting an error with
> >>> TestForest, but only for certain forests that I'm building with
> >>> BuildForest.  Using the same descriptor and same build and test data
> >>> sets I get no error if I set mapred.max.split.size=1890528 which is
> >>> roughly 1/100th the size of the build data set.  I can build the
> >>> forest and test the remaining data and get the results with no
> >>> problem.  When I change the split size to 18905280, everything still
> >>> appears to work fine when building the forest, but when I then try to
> >>> test the remaining data I get the error below.
> >>>
> >>> I've dug around the code a little, but nothing stood out as to why the
> >>> array would go out of bounds at that specific value.  One solution is
> >>> to obviously not create partitions that large, but if it was a problem
> >>> with me running out of memory I would have expected an out of memory
> >>> error and not an index past the size the bounds of an array.  I'd
> >>> obviously prefer larger partitions and thus less of them and can move
> >>> running this job to something like EMR which should allow me to have
> >>> more memory, but I want to understand the nature of the error.
> >>>
> >>> For what it is worth I'm running this on hadoop-1.0.3 and
> mahout-0.8-SNAPSHOT
> >>>
> >>> Thanks.
> >>>
> >>> --
> >>>
> >>> 12/09/05 17:52:09 INFO mapred.JobClient: Task Id :
> >>> attempt_201209031756_0008_m_000000_0, Status : FAILED
> >>> java.lang.ArrayIndexOutOfBoundsException: 946827879
> >>>        at org.apache.mahout.classifier.df.node.Node.read(Node.java:58)
> >>>        at
> org.apache.mahout.classifier.df.DecisionForest.readFields(DecisionForest.java:197)
> >>>        at
> org.apache.mahout.classifier.df.DecisionForest.read(DecisionForest.java:203)
> >>>        at
> org.apache.mahout.classifier.df.DecisionForest.load(DecisionForest.java:225)
> >>>        at
> org.apache.mahout.classifier.df.mapreduce.Classifier$CMapper.setup(Classifier.java:212)
> >>>        at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:142)
> >>>        at
> org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:764)
> >>>        at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370)
> >>>        at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
> >>>        at java.security.AccessController.doPrivileged(Native Method)
> >>>        at javax.security.auth.Subject.doAs(Subject.java:416)
> >>>        at
> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1121)
> >>>        at org.apache.hadoop.mapred.Child.main(Child.java:249)
>

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