On Mon, Apr 15, 2013 at 12:14 PM, Robin Anil <[email protected]> wrote:

> Another crazy idea for the future is to kill the usage of
> OpenIntDoubleHashMap entirely and copy parts of it inside RASV which will
> only deal with nonzero keys and non zero values. RASV can then keep track
> of non-zero elements in a variable to speed up those lookups.
>
>
> Robin Anil | Software Engineer | +1 312 869 2602 | Google Inc.
>
>
> On Mon, Apr 15, 2013 at 2:11 PM, Robin Anil <[email protected]> wrote:
>
> > The point 3 is coming from the philosophy that all Vectors behave the
> same
> > way and numNonDefaultElements of a DenseVector is same as that of a
> > SparseVector. Eg, if PersonSimilarity relies upon it for document length,
> > it should be behave the same way.
> >
> > The point 4 can be solved by killing the iterator interface entirely and
> > creating forEachNonZero(function()) method which will only call if the
> > element is nonzero.
>

Killing iteration would be really really bad, from a useability standpoint.
 In fact,
I've been moving in the other direction: https://reviews.apache.org/r/9867/
adds iterators to the basic collection interface!



>  >
> >
> >
> > On Mon, Apr 15, 2013 at 2:08 PM, Jake Mannix <[email protected]
> >wrote:
> >
> >> On Mon, Apr 15, 2013 at 11:58 AM, Robin Anil <[email protected]>
> >> wrote:
> >>
> >> > This is what I propose:
> >> >
> >> > 1) Allow setting value to zero while iterating (e.set(0.0)).
> >> >
> >>
> >> This is in addition to the fact that we already allow setting nonzero
> >> values
> >> while iterating, right?
> >>
> >>
> >> > 2) Do not allow callers to use vector.set(index, 0.0) during
> iterating).
> >> > This can cause re-hashing. (Can set a dirty bit in the hashmap during
> >> > rehash to throw a concurrent modified exception)
> >> >
> >>
> >> Agreed - this is a commonly accepted requirement: I think in fact we
> >> should pro-actively throw ConcurrentModificationException if someone
> >> tries to call vector.set / vector.assign while iterating.
> >>
> >>
> >> > 3) Update the numNonDefaultElements to iterate over the array to
> >> discount
> >> > 0.0 instead of returning the hashMap values.
> >> > 4) IterateNonZero may iterate over a few zeros if you did set the
> >> dimension
> >> > to 0. Most of the statistics code should handle 0 values correctly.
> >> >
> >>
> >> Yeah, are we really strict about getNumNonDefaultElements really always
> >> returning exactly the number of nonzeroes?  I was under the impression
> >> that
> >> for e.g. DenseVector, it would give the overal size, even if some were
> 0,
> >> and that it was basically tracking the amount of space the vector was
> >> taking
> >> up.  But I can see the argument that it really should return what it
> says
> >> it
> >> returns, if that is relied upon.
> >>
> >>
> >> >
> >> >
> >> >
> >> > Robin Anil | Software Engineer | +1 312 869 2602 | Google Inc.
> >> >
> >> >
> >> > On Mon, Apr 15, 2013 at 1:50 PM, Jake Mannix <[email protected]>
> >> > wrote:
> >> >
> >> > > Ah, this was the one corner case I was worried about - we do
> >> special-case
> >> > > setting to 0,
> >> > > as meaning remove from the hashmap, yes.
> >> > >
> >> > > What's the TL;DR of what you did to work around this?  Should we
> allow
> >> > > this?  Even
> >> > > if it's through the Vector.Element instance, should it be ok?  If
> so,
> >> how
> >> > > to handle?
> >> > >
> >> > >
> >> > > On Mon, Apr 15, 2013 at 11:04 AM, Robin Anil <[email protected]>
> >> > wrote:
> >> > >
> >> > > > I am adding the tests and updating the patch.
> >> > > >
> >> > > > Robin Anil | Software Engineer | +1 312 869 2602 | Google Inc.
> >> > > >
> >> > > >
> >> > > > On Mon, Apr 15, 2013 at 1:03 PM, Robin Anil <[email protected]
> >
> >> > > wrote:
> >> > > >
> >> > > > > You can re-iterate if the state is in iteration. But you cannot
> >> > write.
> >> > > > >
> >> > > > > This is what is happening:
> >> > > > >
> >> > > > > One of the values are becoming 0. So Vector tries to remove it
> >> from
> >> > the
> >> > > > > underlying hashmap. This changes the layout, if a vector has to
> be
> >> > > > mutated
> >> > > > > while iterating, we have to set 0 value in the hashmap and not
> >> remove
> >> > > it
> >> > > > > like what the Vector layer is doing. This adds another
> complexity,
> >> > the
> >> > > > > vector iterator has to deal with skipping over elements with 0
> >> value.
> >> > > > >
> >> > > > >
> >> > > > > Try this
> >> > > > >
> >> > > > > Create a vector of length 13 and set the following values.
> >> > > > >
> >> > > > >
> >> > > > >    1.     double[] val = new double[] { 0, 2, 0, 0, 8, 3, 0, 6,
> >> 0, 1,
> >> > > 1,
> >> > > > >    2, 1 };
> >> > > > >    2.     for (int i = 0; i < val.length; ++i) {
> >> > > > >    3.       vector.set(i, val[i]);
> >> > > > >    4.     }
> >> > > > >
> >> > > > > Iterate again and while iterating set one of the values as zero.
> >> > > > >
> >> > > > > On Mon, Apr 15, 2013 at 12:56 PM, Dan Filimon <
> >> > > > [email protected]
> >> > > > > > wrote:
> >> > > > >
> >> > > > >> What kind of Vector is failing to set() in that code?
> >> > > > >>
> >> > > > >> About the state enum, what if (for whatever reason, not
> >> > > > >> multi-threaded-ness) there are multiple iterators to that
> vector?
> >> > > > >> Something like a reference count (how many iterators point to
> it)
> >> > > would
> >> > > > >> probably be needed, and keeping it sane would only be possible
> in
> >> > one
> >> > > > >> thread. Although this seems kind of brittle.
> >> > > > >>
> >> > > > >> +1 for numNonDefault.
> >> > > > >>
> >> > > > >>
> >> > > > >> On Mon, Apr 15, 2013 at 8:36 PM, Robin Anil <
> >> [email protected]>
> >> > > > wrote:
> >> > > > >>
> >> > > > >>> Another behavior difference.
> >> > > > >>>
> >> > > > >>> The numNonDefaultElement for a DenseVector returns the total
> >> > length.
> >> > > > >>> This causes Pearson Correlation Similarity to differ from if
> it
> >> was
> >> > > > >>> implemented using on of the SparseVector.
> >> > > > >>> I am proposing to fix the numNonDefaultElement to correctly
> >> iterate
> >> > > > over
> >> > > > >>> the dense vector to figure out non zero values ? Sounds ok
> >> > > > >>>
> >> > > > >>> Robin Anil | Software Engineer | +1 312 869 2602 | Google
> Inc.
> >> > > > >>>
> >> > > > >>>
> >> > > > >>> On Mon, Apr 15, 2013 at 12:32 PM, Robin Anil <
> >> [email protected]
> >> > > > >wrote:
> >> > > > >>>
> >> > > > >>>> Found the bug PearsonCorrelationSimilarity was trying to
> mutate
> >> > the
> >> > > > >>>> object while iterating.
> >> > > > >>>>
> >> > > > >>>>
> >> > > > >>>>    1.     while (it.hasNext()) {
> >> > > > >>>>    2.       Vector.Element e = it.next();
> >> > > > >>>>    3.       *vector.set(e.index(),* e.get() - average);
> >> > > > >>>>    4.     }
> >> > > > >>>>
> >> > > > >>>> This has a side effect of causing the underlying hash-map or
> >> > object
> >> > > to
> >> > > > >>>> change.
> >> > > > >>>>
> >> > > > >>>> The right behavior is to set the value of the index while
> >> > iterating.
> >> > > > >>>>
> >> > > > >>>>    1.     while (it.hasNext()) {
> >> > > > >>>>    2.       Vector.Element e = it.next();
> >> > > > >>>>    3.       *e.set(e.get()* - average);
> >> > > > >>>>    4.     }
> >> > > > >>>>
> >> > > > >>>> I am sure we are incorrectly doing the first style across the
> >> code
> >> > > at
> >> > > > >>>> many places.
> >> > > > >>>>
> >> > > > >>>> I am proposing this
> >> > > > >>>>
> >> > > > >>>> When iterating, we lock the set interface on the vector
> using a
> >> > > State
> >> > > > >>>> enum. If anyone tries to mutate, we throw an exception.
> >> > > > >>>> We flip the state when we complete iterating (hasNext =
> false)
> >> or
> >> > > when
> >> > > > >>>> we explicitly close the iterator (adding a close method on
> the
> >> > > > iterator).
> >> > > > >>>>
> >> > > > >>>> Again this is all a single thread fix. if a vector is being
> >> > mutated
> >> > > > and
> >> > > > >>>> iterated across multiple threads, all hell can break loose.
> >> > > > >>>>
> >> > > > >>>> Robin
> >> > > > >>>>
> >> > > > >>>>
> >> > > > >>>>
> >> > > > >>>> On Mon, Apr 15, 2013 at 12:56 AM, Robin Anil <
> >> > [email protected]
> >> > > > >wrote:
> >> > > > >>>>
> >> > > > >>>>> Spoke too soon still failure.  I am uploading the latest
> >> patch.
> >> > > These
> >> > > > >>>>> are the current failing tests.
> >> > > > >>>>>
> >> > > > >>>>>
> >> > > >
> >> > >
> >> >
> >>
>  
> ClusterClassificationDriverTest.testVectorClassificationWithOutlierRemovalMR:103->assertVectorsWithOutlierRemoval:189->checkClustersWithOutlierRemoval:239->Assert.assertTrue:41->Assert.fail:88
> >> > > > >>>>> not expecting cluster:{0:1.0,1:1.0}
> >> > > > >>>>>
> >> > > > >>>>>
> >> > > >
> >> > >
> >> >
> >>
> ClusterClassificationDriverTest.testVectorClassificationWithOutlierRemoval:139->assertVectorsWithOutlierRemoval:189->checkClustersWithOutlierRemoval:239->Assert.assertTrue:41->Assert.fail:88
> >> > > > >>>>> not expecting cluster:{0:1.0,1:1.0}
> >> > > > >>>>>
> >> > > > >>>>>
> >> > > >
> >> > >
> >> >
> >>
> ClusterClassificationDriverTest.testVectorClassificationWithoutOutlierRemoval:121->assertVectorsWithoutOutlierRemoval:193->assertFirstClusterWithoutOutlierRemoval:218->Assert.assertTrue:52->Assert.assertTrue:41->Assert.fail:86
> >> > > > >>>>> null
> >> > > > >>>>>
> >> > > > >>>>>
> >> > > >
> >> > >
> >> >
> >>
> ClusterOutputPostProcessorTest.testTopDownClustering:102->assertPostProcessedOutput:188->assertTopLevelCluster:115->assertPointsInSecondTopLevelCluster:134->Assert.assertTrue:52->Assert.assertTrue:41->Assert.fail:86
> >> > > > >>>>> null
> >> > > > >>>>>
> >> > > > >>>>>
> >> > > >
> >> > >
> >> >
> >>
> VectorSimilarityMeasuresTest.testPearsonCorrelationSimilarity:109->Assert.assertEquals:592->Assert.assertEquals:494->Assert.failNotEquals:743->Assert.fail:88
> >> > > > >>>>> expected:<0.5303300858899108> but was:<0.38729833462074176>
> >> > > > >>>>>
> >> > > > >>>>>
> >> > > > >>>>> Robin Anil | Software Engineer | +1 312 869 2602 | Google
> >> Inc.
> >> > > > >>>>>
> >> > > > >>>>>
> >> > > > >>>>> On Mon, Apr 15, 2013 at 12:24 AM, Robin Anil <
> >> > [email protected]
> >> > > > >wrote:
> >> > > > >>>>>
> >> > > > >>>>>> Found it, fixed it. I am submitting soon.
> >> > > > >>>>>>
> >> > > > >>>>>> Robin Anil | Software Engineer | +1 312 869 2602 | Google
> >> Inc.
> >> > > > >>>>>>
> >> > > > >>>>>>
> >> > > > >>>>>> On Sun, Apr 14, 2013 at 11:56 PM, Ted Dunning <
> >> > > > [email protected]>wrote:
> >> > > > >>>>>>
> >> > > > >>>>>>> Robin,
> >> > > > >>>>>>>
> >> > > > >>>>>>> Can you make sure that the patches are somewhere that Dan
> >> can
> >> > > pick
> >> > > > >>>>>>> up this
> >> > > > >>>>>>> work?  He is in GMT+2 and is probably about to appear on
> the
> >> > > scene.
> >> > > > >>>>>>>
> >> > > > >>>>>>>
> >> > > > >>>>>>>
> >> > > > >>>>>>> On Sun, Apr 14, 2013 at 9:34 PM, Robin Anil <
> >> > > [email protected]>
> >> > > > >>>>>>> wrote:
> >> > > > >>>>>>>
> >> > > > >>>>>>> > Strike that there are still failures. Investigating. if
> I
> >> > cant
> >> > > > fix
> >> > > > >>>>>>> it in
> >> > > > >>>>>>> > the next hour, I will submit them sometime in the
> evening
> >> > > > tomorrow.
> >> > > > >>>>>>> >
> >> > > > >>>>>>> > Robin Anil | Software Engineer | +1 312 869 2602 |
> Google
> >> > Inc.
> >> > > > >>>>>>> >
> >> > > > >>>>>>> >
> >> > > > >>>>>>> > On Sun, Apr 14, 2013 at 11:33 PM, Robin Anil <
> >> > > > [email protected]>
> >> > > > >>>>>>> wrote:
> >> > > > >>>>>>> >
> >> > > > >>>>>>> > > Tests pass. Submitting the patches.
> >> > > > >>>>>>> > >
> >> > > > >>>>>>> > > Robin Anil | Software Engineer | +1 312 869 2602 |
> >> Google
> >> > > Inc.
> >> > > > >>>>>>> > >
> >> > > > >>>>>>> > >
> >> > > > >>>>>>> > > On Sun, Apr 14, 2013 at 11:17 PM, Robin Anil <
> >> > > > >>>>>>> [email protected]>
> >> > > > >>>>>>> > wrote:
> >> > > > >>>>>>> > >
> >> > > > >>>>>>> > >> Added a few more tests. Throw NoSuchElementException
> >> like
> >> > > Java
> >> > > > >>>>>>> > >> Collections when iterating past the end. Things look
> >> > solid,
> >> > > > >>>>>>> performance
> >> > > > >>>>>>> > is
> >> > > > >>>>>>> > >> 2x. All Math tests pass. I am now waiting for the
> >> entire
> >> > > test
> >> > > > >>>>>>> suites to
> >> > > > >>>>>>> > run
> >> > > > >>>>>>> > >> before submitting.
> >> > > > >>>>>>> > >>
> >> > > > >>>>>>> > >> Robin Anil | Software Engineer | +1 312 869 2602 |
> >> Google
> >> > > > Inc.
> >> > > > >>>>>>> > >>
> >> > > > >>>>>>> > >>
> >> > > > >>>>>>> > >> On Sun, Apr 14, 2013 at 9:49 PM, Robin Anil <
> >> > > > >>>>>>> [email protected]>
> >> > > > >>>>>>> > wrote:
> >> > > > >>>>>>> > >>
> >> > > > >>>>>>> > >>> I am not sure what I did. But removing Guava
> Abstract
> >> > > > iterator
> >> > > > >>>>>>> actually
> >> > > > >>>>>>> > >>> sped up the dot, cosine, euclidean by another 60%.
> >> Things
> >> > > are
> >> > > > >>>>>>> now 2x
> >> > > > >>>>>>> > faster
> >> > > > >>>>>>> > >>> than trunk. While also correcting the behavior (I
> >> hope)
> >> > > > >>>>>>> > >>>
> >> > > > >>>>>>> > >>>
> >> > > > >>>>>>> > >>>
> >> > > > >>>>>>> >
> >> > > > >>>>>>>
> >> > > >
> >> > >
> >> >
> >>
> https://docs.google.com/spreadsheet/ccc?key=0AhewTD_ZgznddGFQbWJCQTZXSnFULUYzdURfWDRJQlE#gid=1
> >> > > > >>>>>>> > >>>
> >> > > > >>>>>>> > >>> Robin Anil | Software Engineer | +1 312 869 2602 |
> >> > Google
> >> > > > Inc.
> >> > > > >>>>>>> > >>>
> >> > > > >>>>>>> > >>>
> >> > > > >>>>>>> > >>> On Sun, Apr 14, 2013 at 8:56 PM, Robin Anil <
> >> > > > >>>>>>> [email protected]
> >> > > > >>>>>>> > >wrote:
> >> > > > >>>>>>> > >>>
> >> > > > >>>>>>> > >>>> Also note that this is code gen, I have to create
> >> > > > >>>>>>> > Element$keyType$Value
> >> > > > >>>>>>> > >>>> for each and every combination not just int double.
> >> and
> >> > > also
> >> > > > >>>>>>> update
> >> > > > >>>>>>> > all
> >> > > > >>>>>>> > >>>> callers to user ElementIntDouble instead of
> Element.
> >> Is
> >> > it
> >> > > > >>>>>>> worth it ?
> >> > > > >>>>>>> > >>>>
> >> > > > >>>>>>> > >>>> Robin Anil | Software Engineer | +1 312 869 2602 |
> >> > Google
> >> > > > >>>>>>> Inc.
> >> > > > >>>>>>> > >>>>
> >> > > > >>>>>>> > >>>>
> >> > > > >>>>>>> > >>>> On Sun, Apr 14, 2013 at 8:46 PM, Ted Dunning <
> >> > > > >>>>>>> [email protected]
> >> > > > >>>>>>> > >wrote:
> >> > > > >>>>>>> > >>>>
> >> > > > >>>>>>> > >>>>> Collections (no longer colt collections) are now
> >> part
> >> > of
> >> > > > >>>>>>> mahout math.
> >> > > > >>>>>>> > >>>>>  No
> >> > > > >>>>>>> > >>>>> need to keep them separate.  The lower iterator
> can
> >> > > > reference
> >> > > > >>>>>>> > >>>>> Vector.Element
> >> > > > >>>>>>> > >>>>>
> >> > > > >>>>>>> > >>>>>
> >> > > > >>>>>>> > >>>>> On Sun, Apr 14, 2013 at 6:24 PM, Robin Anil <
> >> > > > >>>>>>> [email protected]>
> >> > > > >>>>>>> > >>>>> wrote:
> >> > > > >>>>>>> > >>>>>
> >> > > > >>>>>>> > >>>>> > I would have loved to but Element is a sub
> >> interface
> >> > in
> >> > > > >>>>>>> Vector. If
> >> > > > >>>>>>> > >>>>> we want
> >> > > > >>>>>>> > >>>>> > to keep colt collections separate we have to
> keep
> >> > this
> >> > > > >>>>>>> separation.
> >> > > > >>>>>>> > >>>>> >
> >> > > > >>>>>>> > >>>>>
> >> > > > >>>>>>> > >>>>
> >> > > > >>>>>>> > >>>>
> >> > > > >>>>>>> > >>>
> >> > > > >>>>>>> > >>
> >> > > > >>>>>>> > >
> >> > > > >>>>>>> >
> >> > > > >>>>>>>
> >> > > > >>>>>>
> >> > > > >>>>>>
> >> > > > >>>>>
> >> > > > >>>>
> >> > > > >>>
> >> > > > >>
> >> > > > >
> >> > > >
> >> > >
> >> > >
> >> > >
> >> > > --
> >> > >
> >> > >   -jake
> >> > >
> >> >
> >>
> >>
> >>
> >> --
> >>
> >>   -jake
> >>
> >
> >
>



-- 

  -jake

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