Hi Mark,

We haven’t had too much discussion about the TP on this list but you ask
some interesting questions below. We don’t really know a huge amount but we
do know it can learn extremely long sequences. Consider that each
transition in a sequence is represented by a number of segments. Each step
at a minimum would consume at least activationThreshold segments since you
need that many active columns to go on to the next step.  So, one limit
with our typical configuration is (128 segments per cell * 32 cells per
column * 2048)/activationThreshold. That’s a sequence about 1/2 million
steps long! We could theoretically “hand construct” a sequence that long
and it should work.

In practice the length is likely to be a lot lower but it’s still probably
pretty long (it would be interesting to try this out with random SDR’s).
 The length is not really the problem. The difficulty of the sequences
(like the one you have below) is more interesting. We have some tests
already in NuPIC of lower order vs high order sequences. Please take a look
at this file:

nupic/tests/integration/py2/nupic/algorithms/tp_test.py

It would be really cool to expand on this type of test.   There’s a lot
more we could do to understand the TP better!

—Subutai


On Sun, Nov 17, 2013 at 3:00 PM, Marek Otahal <[email protected]> wrote:

> I'm about to create and carry out some benchmarks of the CLA.
>
>
> -for TP: given n-sequences, what's the max length f the sequences it can
> recall?
> -test with hardest sequences? (AAAAAAAAAAAAAAAAAAAAAAAAAAAAB)
> -resistance to noice (I think Subutai did these? Could we have the graphs,
> scripts, please?)
>
>
>
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