Mahout wiht POI

2012-11-28 Thread Guillermo González Suárez
Hello: I’m a new user of Mahout library, I test his algorithms with good results, but I need information about who use of the recommender algorithm in POI recommendations for a geospatial applications, thanks, bests regards.

Re: Empty clusteredPoints after Dirichlet clustering

2012-11-28 Thread Jeff Eastman
The classification phase of Dirichlet uses a most-likely assignment of points to clusters by default. This means that, unlike the training phase where points are assigned statistically to likely clusters, the classification may result in empty clusters even though those clusters have nonzero

Mahout SGD - is it really descent?

2012-11-28 Thread David Kincaid
While trying to wrap my head around the Mahout code for SGD I noticed that the update to the beta terms seems to be doing gradient ascent and not descent. Could someone help me find the missing minus sign? The line of code in question from AbstractOnlineLogisticRegression.java, train() is:

Re: Mahout SGD - is it really descent?

2012-11-28 Thread David Arthur
My completely unfounded guess would be the sign is built into gradientBase On Nov 28, 2012, at 2:19 PM, David Kincaid wrote: While trying to wrap my head around the Mahout code for SGD I noticed that the update to the beta terms seems to be doing gradient ascent and not descent. Could someone

Re: Mahout SGD - is it really descent?

2012-11-28 Thread David Kincaid
I thought it might be too, but doesn't look like it to me. Of course, I really have a hard time following vector and matrix math done in Java. Does v.minus(r) mean v - r or r - v? On Wed, Nov 28, 2012 at 1:28 PM, David Arthur mum...@gmail.com wrote: My completely unfounded guess would be the

RE: Mahout SGD - is it really descent?

2012-11-28 Thread Lancaster, Robert (Orbitz)
graidentBase is coming from: double gradientBase = gradient.get(i); Prior to that: Vector gradient = this.gradient.apply(groupKey, actual, instance, this); this.gradient is an instance of DefaultGradient (in the same project). The last two lines of the apply function are: r.assign(v,

Re: Mahout SGD - is it really descent?

2012-11-28 Thread Ted Dunning
Robert's analysis is correct. This would be worthy of a comment at the least. On Wed, Nov 28, 2012 at 11:53 AM, Lancaster, Robert (Orbitz) robert.lancas...@orbitz.com wrote: graidentBase is coming from: double gradientBase = gradient.get(i); Prior to that: Vector gradient =

Re: Mahout SGD - is it really descent?

2012-11-28 Thread Jake Mannix
or maybe call the variable negativeGradient, instead? On Wed, Nov 28, 2012 at 12:50 PM, Ted Dunning ted.dunn...@gmail.com wrote: Robert's analysis is correct. This would be worthy of a comment at the least. On Wed, Nov 28, 2012 at 11:53 AM, Lancaster, Robert (Orbitz)

Re: Mahout SGD - is it really descent?

2012-11-28 Thread David Kincaid
Thanks much, Robert. I see it now. I think I've got the basics of the implementation down now. On Wed, Nov 28, 2012 at 1:53 PM, Lancaster, Robert (Orbitz) robert.lancas...@orbitz.com wrote: graidentBase is coming from: double gradientBase = gradient.get(i); Prior to that: Vector gradient =

Re: Mahout SGD - is it really descent?

2012-11-28 Thread Ted Dunning
+1 On Wed, Nov 28, 2012 at 12:56 PM, Jake Mannix jake.man...@gmail.com wrote: or maybe call the variable negativeGradient, instead?

Re: Visualizing class hierarchy of mahout

2012-11-28 Thread tuxdna
Please to be using UMLGraph [1]. It works very nicely. /tuxdna [1] http://www.umlgraph.org/ On Wed, Nov 28, 2012 at 8:12 PM, Ahmet Ylmaz ahmetyilmazefe...@yahoo.com wrote: Hi, I'm trying to learn the internals of Mahout. How can I visualize the class hierarchy in a UML style? Are there