PDL::OpenCV wraps a kmeans function, so that might also help.

Best regards,
Ed
________________________________
From: Boyd Duffee <boyd.duf...@gmail.com>
Sent: Wednesday, November 22, 2023 12:19 PM
To: Aldobranti <aldobra...@gmail.com>
Cc: pdl-general@lists.sourceforge.net <pdl-general@lists.sourceforge.net>
Subject: Re: [Pdl-general] getting started with K-means

Hi Aldo,
The documentation is pretty good.  You can change the number of clusters like so

my $k = $pdl->kmeans( {NCLUS => 10} );

There are also a few blog posts that show some of the process from a learners' 
perspective
https://blogs.perl.org/users/enkidu/2019/12/its-beginning-to-look-a-lot-like-k-means.html
There's not a lot of examples out there, so if you can blog your experience 
(good or bad), that'll add to the available docs for the next person.  
dev.to<http://dev.to> gets a lot of exposure these days.

best of luck,
Boyd

On Wed, 22 Nov 2023 at 10:48, Aldobranti 
<aldobra...@gmail.com<mailto:aldobra...@gmail.com>> wrote:

my problem area is to analyse electrical power switching events and tie back 
readings of reactive and resistive loads aiming to point back at specific items 
of plant hardware.

So I thought cluster analysis and got a steer towards PDL

In a perl script I write

use PDL::Stats::KMeans;

...
my $sql = "select resistv_chg,reactv_chg from metered_events where 
matched_event_id is not null";
my $pdl = rdbi2D( $dbh, $sql );  # pdl info tells me that i have a 2D array of 
~ 1400 x 2
my $k = $pdl->kmeans( {} );

First up I see that this is not unrestrained -- the default of NCLUS is 3 and 
[seems to me] that I am being defeated in trying to identify between 10 and 20 
clusters associated with the electrical characteristics of the 10 - 20 items in 
my plant

being a simple minded chap all I want is an array[10] of mean and stdvars for 
the data set

Could anybody spare the time to get me started?
Aldo
--
Aldobranti: A performance in digital social media and large sheets of
photographic film https://aldobranti.org



_______________________________________________
pdl-general mailing list
pdl-general@lists.sourceforge.net<mailto:pdl-general@lists.sourceforge.net>
https://lists.sourceforge.net/lists/listinfo/pdl-general


--
Boyd Duffee
  No pain, no French bread - Teresa Monachino
_______________________________________________
pdl-general mailing list
pdl-general@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/pdl-general

Reply via email to