FP-Growth

[Yarco Hayduk <ya...@gmail.com>]

Hi,

I'm having trouble understanding some of the code in the FP-Growth
algorithm.

What is the purpose of the

minSupportValue = Math.max(minSupportValue,
                            minSupport.longValue() / 2);

line. When exactly can the minsup value change?

yarco;)

Re: FP-Growth

[Yarco Hayduk <ya...@gmail.com>]

Not really,

We don't need to change the minsup at any point really. But I will
investigate some more.

I'm currently testing a different technique for building conditional trees
(trying to remove the bonsai pruning completely) and collecting/outputting
closed FP's. The current  implementation uses way too many heaps to collect
patterns (their creation is expensive, and this is a bottleneck as we are
creating a new heap (where the PriorityQueue creation takes lots of time)
every time we are mining a single-path tree). We can limit ourselves to
having just N heaps, where N is the number of frequent singleton patterns.

Seems like I can even use a different thread for pattern collection
purposes, as the mining and pattern collection can overlap.

If I get any significant results, will let you know.

yarco;)

On Mon, Jun 27, 2011 at 5:38 PM, Robin Anil <ro...@gmail.com> wrote:

> I dont remember about the (/2) part. But the line was supposed to get the
> min support of the mined conditional tree and raise the minSupportValue for
> subsequent mining of conditional trees up the header table. Does that make
> sense?
>
> Robin
>
> On Tue, Jun 28, 2011 at 3:32 AM, Yarco Hayduk <ya...@gmail.com> wrote:
>
> > Hi,
> >
> > I'm having trouble understanding some of the code in the FP-Growth
> > algorithm.
> >
> > What is the purpose of the
> >
> > minSupportValue = Math.max(minSupportValue,
> >                            minSupport.longValue() / 2);
> >
> > line. When exactly can the minsup value change?
> >
> > yarco;)
> >
>

Re: FP-Growth

[Robin Anil <ro...@gmail.com>]

I dont remember about the (/2) part. But the line was supposed to get the
min support of the mined conditional tree and raise the minSupportValue for
subsequent mining of conditional trees up the header table. Does that make
sense?

Robin

On Tue, Jun 28, 2011 at 3:32 AM, Yarco Hayduk <ya...@gmail.com> wrote:

> Hi,
>
> I'm having trouble understanding some of the code in the FP-Growth
> algorithm.
>
> What is the purpose of the
>
> minSupportValue = Math.max(minSupportValue,
>                            minSupport.longValue() / 2);
>
> line. When exactly can the minsup value change?
>
> yarco;)
>