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From Jake Mannix <jake.man...@gmail.com>
Subject Re: understanding vectors
Date Mon, 14 Jan 2013 21:35:24 GMT
We don't have a way to add the code to 0.7, it would just go in trunk.


On Mon, Jan 14, 2013 at 1:19 PM, Koert Kuipers <koert@tresata.com> wrote:

> since trunk behaves properly, where do you want unit test? in version 0.7?
>
> On Mon, Jan 14, 2013 at 3:59 PM, Jake Mannix <jake.mannix@gmail.com>
> wrote:
>
> > I could have sworn we've seen and fixed this bug before, but I guess not.
> >  Let's get a (failing) unit test in there, and then it should be an easy
> > fix.
> >
> > I think nobody runs into this because it's really rare to want to iterate
> > over all of the entries in a sparse vector - iterateNonZero() is used
> > almost exclusively for these.
> >
> >
> > On Mon, Jan 14, 2013 at 12:51 PM, Koert Kuipers <koert@tresata.com>
> wrote:
> >
> > > not the same behavior in trunk. SequentialAccessVector.iterator seems
> to
> > > behave properly there.
> > >
> > > On Mon, Jan 14, 2013 at 3:07 PM, Koert Kuipers <koert@tresata.com>
> > wrote:
> > >
> > > > sorry yes i meant 0.7
> > > >
> > > > On Mon, Jan 14, 2013 at 12:58 PM, Jake Mannix <jake.mannix@gmail.com
> > > >wrote:
> > > >
> > > >> I think you mean 0.7, right?  Can you see if you get the same
> behavior
> > > in
> > > >> svn trunk?
> > > >>
> > > >>
> > > >> On Mon, Jan 14, 2013 at 9:21 AM, Koert Kuipers <koert@tresata.com>
> > > wrote:
> > > >>
> > > >> > i am using version mahout 7.0
> > > >> >
> > > >> > On Mon, Jan 14, 2013 at 10:15 AM, Ted Dunning <
> > ted.dunning@gmail.com>
> > > >> > wrote:
> > > >> >
> > > >> > > Which version are you using?
> > > >> > >
> > > >> > > (this misbehavior sounds familiar)
> > > >> > >
> > > >> > > iterator() should return all values.
> > > >> > >
> > > >> > > iterateNonZero() is allowed to skip zeros.
> > > >> > >
> > > >> > > On Mon, Jan 14, 2013 at 6:11 AM, Koert Kuipers <
> koert@tresata.com
> > >
> > > >> > wrote:
> > > >> > >
> > > >> > > > i am looking at the iterators for DenseVector,
> > > >> > RandomAcccessSparseVector
> > > >> > > > and SequentialAccessSparseVector.
> > > >> > > >
> > > >> > > > for both DenseVector and RandomAcccessSparseVector
the
> iterator
> > > >> seems
> > > >> > to
> > > >> > > > return all values, including the missing zero values.
> > > >> > > > for SequentialAccessSparseVector the iterator also
returns all
> > > >> values,
> > > >> > > but
> > > >> > > > only up to the last non-missing value!
> > > >> > > >
> > > >> > > > is this by design? what is a vector iterator supposed
to
> return
> > > >> > exactly?
> > > >> > > i
> > > >> > > > can't see a logical pattern/consistency. see examples
below.
> > > >> > > > thanks! koert
> > > >> > > >
> > > >> > > > scala> val x = new
> > > >> org.apache.mahout.math.RandomAccessSparseVector(5)
> > > >> > > > x: org.apache.mahout.math.RandomAccessSparseVector
= {}
> > > >> > > >
> > > >> > > > scala> x.set(3, 1.0)
> > > >> > > >
> > > >> > > > scala> for (item <- x.iterator.asScala) println((item.index,
> > > >> item.get))
> > > >> > > > (0,0.0)
> > > >> > > > (1,0.0)
> > > >> > > > (2,0.0)
> > > >> > > > (3,1.0)
> > > >> > > > (4,0.0)
> > > >> > > >
> > > >> > > > scala> val y = new
> > > >> > org.apache.mahout.math.SequentialAccessSparseVector(5)
> > > >> > > > y: org.apache.mahout.math.SequentialAccessSparseVector
= {
> > > >> > > >
> > > >> > > > scala> y.set(3, 1.0)
> > > >> > > >
> > > >> > > > scala> for (item <- y.iterator.asScala) println((item.index,
> > > >> item.get))
> > > >> > > > (0,0.0)
> > > >> > > > (1,0.0)
> > > >> > > > (2,0.0)
> > > >> > > > (3,1.0)
> > > >> > > >
> > > >> > >
> > > >> >
> > > >>
> > > >>
> > > >>
> > > >> --
> > > >>
> > > >>   -jake
> > > >>
> > > >
> > > >
> > >
> >
> >
> >
> > --
> >
> >   -jake
> >
>



-- 

  -jake

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