Thread: PGSQL: Fuzzy C means algorithms in MAdlib

PGSQL: Fuzzy C means algorithms in MAdlib

From
Akansha Singh
Date:
HI
 I would like to know can this algorithm be implemented on MAdlIB
In the K-means algorithm, each vector is classified as belonging to a single cluster (hard clustering), and the
centroidsare updated based on the classified samples. In a variation of this approach known as fuzzy c-means [2, 29],
allvectors have a degree of membership for each cluster, and the respective centroids are calculated based on these
membershipdegrees. 

Whereas the K-means algorithm computes the average of the vectors in a cluster as the center, fuzzy c-means finds the
centeras a weighted average of all points, using the membership probabilities for each point as weights. Vectors with a
highprobability of belonging to the class have larger weights, and more influence on the centroid. 

Regards
Akansha Singh


Re: PGSQL: Fuzzy C means algorithms in MAdlib

From
Atri Sharma
Date:

Sent from my iPad

On 27-Apr-2013, at 16:04, Akansha Singh <akansha.singh@oracle.com> wrote:

> HI
> I would like to know can this algorithm be implemented on MAdlIB
> In the K-means algorithm, each vector is classified as belonging to a single cluster (hard clustering), and the
centroidsare updated based on the classified samples. In a variation of this approach known as fuzzy c-means [2, 29],
allvectors have a degree of membership for each cluster, and the respective centroids are calculated based on these
membershipdegrees. 
>
> Whereas the K-means algorithm computes the average of the vectors in a cluster as the center, fuzzy c-means finds the
centeras a weighted average of all points, using the membership probabilities for each point as weights. Vectors with a
highprobability of belonging to the class have larger weights, and more influence on the centroid. 

I would suggest marking the MADlib devel list as well.

This seems like an easy to do variation of k means, and should be doable and built over the existing k means resources
inMADLib. 

Regards,

Atri