Hi Andy & Ken,

Thanks Ken for the alternative but I am using a cosine distance.
Andy, concerning the computation of the mean, the function has to be 
configurable too but the default function mean is also good for cosine & 
bregman divergence (http://www-users.cs.umn.edu/~kumar/dmbook/ch8.pdf  see 
table 8.2 page 501). Yes I could implement easily k-means but I will lose lot 
of benefits from sklearn frameworks such as the ability to compare easily 
several unsupervised algorithms.  I was simply expected the distance function 
to be configurable as it is with many other sklearn functions.

On the other hand, do you know why 
metrics.cluster.unsupervised.silhouette_score required the labels? I understand 
that we can compute the supervised version of the silhouette score but was 
looking for the unsupervised version. Even the help doesn’t mention anywhere 
the labels.

I am trying to push for sklearn in my team, quite impress so far.
Thanks,
Francis



From: Kenneth C. Arnold [mailto:[email protected]]
Sent: April-02-13 3:32 PM
To: [email protected]
Subject: Re: [Scikit-learn-general] kmeans distance function not configurable

If you want a Mahalanobis distance, though, you can instead just transform your 
data using the Cholesky decomposition of the distance matrix.

-Ken

On Tue, Apr 2, 2013 at 3:09 PM, Andreas Mueller 
<[email protected]<mailto:[email protected]>> wrote:
Hi Francis.
No. It is highly non-trivial for most distance functions to do k-means as
the computation of the mean has to be replaced by a different computation.

If you know how to do that, implementing k-means in pure numpy is not all that 
hard.

This question comes up quite a lot. Maybe we should do a faq or something.

Cheers,
Andy


On 04/02/2013 09:05 PM, Pieraut, Francis wrote:
Hi guys,

Is there is simple way to change the distance function used in the kmeans 
implementation?

Thanks,
Francis



------------------------------------------------------------------------------

Minimize network downtime and maximize team effectiveness.

Reduce network management and security costs.Learn how to hire

the most talented Cisco Certified professionals. Visit the

Employer Resources Portal

http://www.cisco.com/web/learning/employer_resources/index.html


_______________________________________________

Scikit-learn-general mailing list

[email protected]<mailto:[email protected]>

https://lists.sourceforge.net/lists/listinfo/scikit-learn-general


------------------------------------------------------------------------------
Minimize network downtime and maximize team effectiveness.
Reduce network management and security costs.Learn how to hire
the most talented Cisco Certified professionals. Visit the
Employer Resources Portal
http://www.cisco.com/web/learning/employer_resources/index.html
_______________________________________________
Scikit-learn-general mailing list
[email protected]<mailto:[email protected]>
https://lists.sourceforge.net/lists/listinfo/scikit-learn-general

------------------------------------------------------------------------------
Minimize network downtime and maximize team effectiveness.
Reduce network management and security costs.Learn how to hire 
the most talented Cisco Certified professionals. Visit the 
Employer Resources Portal
http://www.cisco.com/web/learning/employer_resources/index.html
_______________________________________________
Scikit-learn-general mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/scikit-learn-general

Reply via email to