I saw a similar guide for C but not for python, so I just assumed that it
didn't exist. Thanks for pointing this out. I want a clarification about
the indentation. I'm so used to using tab to indent in python. I wonder if
its ok if I keep using tabs instead of the specified 2 spaces.


On Tue, Feb 25, 2014 at 4:52 AM, Matthew Taylor <[email protected]> wrote:

> Hey Kevin,
>
> Thanks so much for taking this task on. I like the direction this
> tutorial is going. Once complete, we should be able to create a nice
> reference document to describe it. You should take a look at our
> python coding conventions[1], as we'll need to make sure all code
> within nupic adheres to the same standard. I'd eventually like to get
> your tutorial into the nupic repo, so reviewing the python style guide
> and running pylint now will probably save you some trouble later. :)
>
>
> [1] https://github.com/numenta/nupic/wiki/Python-Style-Guide
> ---------
> Matt Taylor
> OS Community Flag-Bearer
> Numenta
>
>
> On Mon, Feb 24, 2014 at 2:35 PM, Subutai Ahmad <[email protected]>
> wrote:
> >
> > It is great to see this taking shape. I've left comments in the issue
> that
> > is tracking this work:
> >
> > https://github.com/numenta/nupic/issues/654
> >
> > Note that we are actually in the process of removing FlatSpatialPooler
> (see
> > https://github.com/numenta/nupic/issues/627). The high tier stuff was a
> hack
> > for tiny datasets, and we don't seem to need it anymore.
> >
> > --Subutai
> >
> >
> > On Mon, Feb 24, 2014 at 11:05 AM, Scott Purdy <[email protected]> wrote:
> >>
> >> Thanks for raising these issues. I understand how that could be
> confusing
> >> and part of it is why we have separated the FlatSpatialPooler from the
> more
> >> general SpatialPooler class.
> >>
> >> Hopefully Subutai can chime in since he understands high tier much
> better
> >> than me but here are my suspicions for the behavior:
> >>
> >> 1. The FlatSpatialPooler implementation includes high tier which causes
> it
> >> to try to memorize the initial patterns it sees. It will try to uniquely
> >> represent the initial patterns. Since the first set of columns hasn't
> had
> >> time to adjust to connect to all of the active bits in its potential
> pool,
> >> there is an opportunity for other columns with high initial boost (part
> of
> >> high tier) to win instead. This is my suspicion but not 100% sure.
> >>
> >> High tier solves some problems but causes others. When we were designing
> >> the new SP implementations we had an explicit goal of separating it
> from the
> >> general SpatialPooler class.
> >>
> >> 2. The FlatSpatialPooler has an optimized path for no topology. This
> could
> >> result in a noticeable difference in speed, even when you specify no
> >> topology in the SpatialPooler. We could have included the optimization
> in
> >> the regular SpatialPooler class but decided that special-casing made
> more
> >> sense in a subclass. We wanted to keep the code really simple and clean
> in
> >> the generic version.
> >>
> >>
> >> On Sun, Feb 23, 2014 at 11:28 PM, Kevin Martin
> >> <[email protected]> wrote:
> >>>
> >>> Tinkering a bit, I came to notice that if I used the SpatialPooler
> class
> >>> instead of FlatSpatialPooler, I get the same set of active columns for
> the
> >>> same input. But it takes much longer to get the results and the 'busy'
> light
> >>> of my computer stays on for a really long time. From what I read, I had
> >>> assumed that the only real difference between the normal spatial
> pooler and
> >>> the flat spatial pooler was the lack of topology. But since both of
> them
> >>> returned different results I think FSP is minimalistic in much more
> ways
> >>> (the SP returns the expected result, while the FSP returns a new
> result for
> >>> the same input vector which was not what I had expected). But I'd
> still like
> >>> to know why the Flat SP returned different set of active columns for
> the
> >>> same input.
> >>>
> >>> On Sun, Feb 23, 2014 at 11:19 AM, Kevin Martin
> >>> <[email protected]> wrote:
> >>>>
> >>>> I'm on my way to writing a 'hello world' equivalent for nupic. I
> decided
> >>>> to work with a flat spatial pooler since it has no topology. I was
> able to
> >>>> send in an input vector and get the list of active columns. The
> source code
> >>>> is hosted here :
> >>>>
> >>>>
> https://github.com/lonesword/nupichelloworld/blob/master/helloworld.py
> >>>>
> >>>> I was under the assumption that similar inputs to the spatial pooler
> >>>> results in similar SDRs. That is, if I give the same input twice, it
> is
> >>>> expected to produce the same SDRs.
> >>>>
> >>>> However, sending the same input vector to the compute() function
> returns
> >>>> a different set of active columns every time. I'm pasting the code
> snippet
> >>>> here :
> >>>>
> >>>> for i in range(10):
> >>>>   example.flat.compute(testinput,True,active)
> >>>>   for i in range(4096):
> >>>>     if active[i]!=0:
> >>>>       print i,
> >>>>   print " "
> >>>>   active[0:]=0
> >>>>
> >>>> flat is an object of FlatSpatialPooler,
> >>>> testinput is the input array,
> >>>> active is the active list of columns.
> >>>>
> >>>> I got a different set of active columns for each iteration. Why is
> this
> >>>> so? I'm feeding the pooler the same input vector each time.
> >>>
> >>>
> >>>
> >>> _______________________________________________
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> >>> [email protected]
> >>> http://lists.numenta.org/mailman/listinfo/nupic_lists.numenta.org
> >>>
> >>
> >>
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> >>
> >
> >
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