Albyn -
That's a very important fact that I overlooked in my
original response. Thanks for pointing it out.
- Phil
On Wed, 3 Mar 2010, Albyn Jones wrote:
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
spec...@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
Details:-------------------------------------------------------
Contact me: tal.gal...@gmail.com | 972-52-7275845
Read me: www.talgalili.com (Hebrew) | www.biostatistics.co.il (Hebrew) |
www.r-statistics.com (English)
----------------------------------------------------------------------------------------------
On Wed, Mar 3, 2010 at 9:14 PM, naama <nw...@technion.ac.il> wrote:
How can I perform cluster analysis using the mahalanobis distance instead
of
the euclidean distance?
thank you
Naama Wolf
--
View this message in context:
http://n4.nabble.com/cluster-with-mahalanobis-distance-tp1577038p1577038.html
Sent from the R help mailing list archive at Nabble.com.
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
[[alternative HTML version deleted]]
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
