[R] cluster with mahalanobis distance

[Albyn Jones]

Note: this procedure assumes that all clusters have the same covariance matrix.

albyn

On Wed, Mar 03, 2010 at 01:23:37PM -0800, Phil Spector wrote:
> The manhattan distance and the Mahalanobis distances are quite different.  
> One of the main differences is that a covariance matrix is necessary to 
> calculate the Mahalanobis
> distance, so it's not easily accomodated by dist.  There is a function in 
> base R which does calculate the Mahalanobis
> distance -- mahalanobis().  So if you pass a distance matrix
> calculated by mahalanobis() to the clustering function, you'll
> get what you want.
> 					- Phil Spector
> 					 Statistical Computing Facility
> 					 Department of Statistics
> 					 UC Berkeley
> 					 spector at stat.berkeley.edu
>
>
> On Wed, 3 Mar 2010, Tal Galili wrote:
>
>> when you create the distance function to put into the hclust, use:
>>
>> dist(x, method = "manhattan")
>>
>>
>> Tal
>>
>>
>>
>> ----------------Contact
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>> ----------------------------------------------------------------------------------------------
>>
>>
>>
>>
>> On Wed, Mar 3, 2010 at 9:14 PM, naama <nwolf at technion.ac.il> wrote:
>>
>>>
>>> How can I perform cluster analysis using the mahalanobis distance instead
>>> of
>>> the euclidean distance?
>>> thank you
>>> Naama Wolf
>>>
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>
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>