Displaying 20 results from an estimated 300 matches similar to: "cluster analysis"
2008 Oct 09
2
vectorization instead of using loop
Dear all,
I've sent this question 2 days ago and got response from Sarah. Thanks for
that. But unfortunately, it did not really solve our problem. The main issue
is that we want to use our own (manipulated) covariance matrix in the
calculation of the mahalanobis distance. Does anyone know how to vectorize
the below code instead of using a loop (which slows it down)?
I'd really appreciate
2003 Sep 17
1
can't run swat
hello,
every time i'like to run swat i get this massage :
An error occured while loading http://localhost:901/:
Could not connect to host localhost (port 901)
i'have checked my /etc/servers,and it OK
But i have a wireless network card ,is that a problem !
help
2008 Oct 07
1
vectorization of a loop for mahalanobis distance calculation
Dear all,
We have a data frame x with n people as rows and k variables as columns.
Now, for each person (i.e., each row) we want to calculate a distance
between him/her and EACH other person in x. In other words, we want to
create a n x n matrix with distances (with zeros in the diagonal).
However, we do not want to calculate Euclidian distances. We want to calculate
Mahalanobis distances, which
2012 Apr 04
1
(no subject)
Hi Moray,
?
Thanks for your answer. It could help but only partially.
?
The script name logon%u.cmd was a bad example. Actually, a user can log on from WinXP , or Win 7 workstations, and I'like to run different logon scripts depending on the OS . So having logon script = logon%a.cmd in the smb.conf generally works thanks to variable substitution.
?
But for user accounts that have been
2023 Feb 06
1
[PATCH] Class-imposed login restrictions
On Sat, 5 Nov 2022 at 14:49, Ed Maste <emaste at freebsd.org> wrote:
>
> From: Yuichiro Naito <naito.yuichiro at gmail.com>
>
> If the following functions are available,
> add an additional check if users are allowed to login imposed by login class.
>
> * auth_hostok(3)
> * auth_timeok(3)
>
> These functions are implemented on FreeBSD.
>
> ---
>
2022 Nov 05
1
[PATCH] Class-imposed login restrictions
From: Yuichiro Naito <naito.yuichiro at gmail.com>
If the following functions are available,
add an additional check if users are allowed to login imposed by login class.
* auth_hostok(3)
* auth_timeok(3)
These functions are implemented on FreeBSD.
---
>From GitHub pull request https://github.com/openssh/openssh-portable/pull/262
auth.c | 18 ++++++++++++++++++
configure.ac |
2011 Sep 26
2
Mahalanobis Distance
Hello R helpers,
I'm trying to use Mahalanobis distance to calculate distance of two time
series, to make some comparations with euclidean distance, DTW, etc, but I'm
having some dificults.
I have, for example, two objects:
s.1 <- c( 5.6324702, 1.3994353, -3.2572327, -3.8311846, -1.2248719,
0.9894694, -2.2835332, -5.1969285, -5.2823988, -3.1499400, -1.7307950,
2.8221209,
2010 Jan 30
2
Questions on Mahalanobis Distance
Hello,
I am a new R user and trying to learn how to implement the mahalanobis
function to measure the distance between to 2 population centroids. I
have used STATISTICA to calculate these differences, but was hoping to learn
to do the analysis in R. I have implemented the code as below, but my
results are very different from that of STATISTICA, and I believe I may not
have interpreted the help
2004 Sep 12
2
mahalanobis distance
Is there a function that calculate the mahalanobis distance in R .
The dist function calculates "euclidean"', '"maximum"', '"manhattan"',
'"canberra"',
'"binary"' or '"minkowski"'.
Thanks ../Murli
2004 Mar 26
1
Mahalanobis
Dear all
Why isn'it possible to calculate Mahalanobis distances with R for a matrix
with 1 row (observations) more than the number of columns (variables)?
> mydata <- matrix(runif(12,-5,5), 4, 3)
> mahalanobis(x=mydata, center=apply(mydata,2,mean), cov=var(mydata))
[1] 2.25 2.25 2.25 2.25
> mydata <- matrix(runif(420,-5,5), 21, 20)
> mahalanobis(x=mydata,
2005 Jul 06
1
Help: Mahalanobis distances between 'Species' from iris
Dear R list,
I'm trying to calculate Mahalanobis distances for 'Species' of 'iris' data
as obtained below:
Squared Distance to Species From Species:
Setosa Versicolor Virginica
Setosa 0 89.86419 179.38471
Versicolor 89.86419 0 17.20107
Virginica 179.38471 17.20107 0
This distances above were obtained with proc
2011 Mar 22
1
Using the mahalanobis( ) function
Hello all,
I am a 2 month newbie to R and am stumped. I have a data set that I've run multivariate stats on using the manova function (I included the data set). Now it comes time for a table of effect sizes with significance. The univariate tests are easy. Where I run into trouble filling in the table of effect sizes is the Mahalanobis D as an effect size. I've included the table so
2005 Jun 24
1
Mahalanobis distances
Dear R community
Have just recently got back into R after a long break and have been amazed at
how much it has grown, and how active the list is! Thank you so much to all
those who contribute to this amazing project.
My question:
I am trying to calculate Mahalanobis distances for a matrix called "fgmatrix"
>dim(fgmatrix)
[1] 76 15
>fg.cov <- cov.wt(fgmatrix)
2011 Mar 20
1
Using the Mahalanobis Function
Hello all,
I am a 2 month newbie to R and am stumped. I have a data set that I've run multivariate stats on using the manova function (I included the data set). Now it comes time for a table of effect sizes with significance. The univariate tests are easy. Where I run into trouble filling in the table of effect sizes is the Mahalanobis D as an effect size. I've included the table so
2010 Jun 22
1
Mahalanobis distance
I am a new R user. i have a question about Mahalanobis distance.actually i have 300 rows and 7 columns. columns are different measurements, 300 rows are genes. since genes can
classify into 4 categories. i used dist() with euclidean distance and cmdscale to do MDS plot. but find out Mahalanobis distance may be
better. how do i use Mahalanobis() to generate similar dist object which i can use
2004 Jan 21
1
outlier identification: is there a redundancy-invariant substitution for mahalanobis distances?
Dear R-experts,
Searching the help archives I found a recommendation to do multivariate
outlier identification by mahalanobis distances based on a robustly estimated
covariance matrix and compare the resulting distances to a chi^2-distribution
with p (number of your variables) degrees of freedom. I understand that
compared to euclidean distances this has the advantage of being scale-invariant.
2005 Jul 08
5
Help with Mahalanobis
Dear R list,
I'm trying to calculate Mahalanobis distances for 'Species' of 'iris' data
as obtained below:
Squared Distance to Species From Species:
Setosa Versicolor Virginica
Setosa 0 89.86419 179.38471
Versicolor 89.86419 0 17.20107
Virginica 179.38471 17.20107 0
These distances were obtained with proc 'CANDISC'
2005 Aug 08
2
selecting outliers
Hi everybody,
I'd like to know if there's an easy way for extracting
outliers record from a dataset, in order to perform
further analysis on them.
Thanks
Alessandro
2009 Jul 20
2
mahalanobis distance
http://www.nabble.com/file/p24569511/mahalanobis.txt mahalanobis.txt
http://www.nabble.com/file/p24569511/concentrations.txt concentrations.txt
Dear Forum members,
I have a problem calculating mahalanobis distances. My data file
mahalanobis.txt and categories file concentrations.txt are attached. I do
the following steps:
x <- as.matrix(read.table("mahalanobis.txt", header=TRUE))
2007 Feb 20
1
Mahalanobis distance and probability of group membership using Hotelling's T2 distribution
I want to calculate the probability that a group will include a particular
point using the squared Mahalanobis distance to the centroid. I understand
that the squared Mahalanobis distance is distributed as chi-squared but that
for a small number of random samples from a multivariate normal population
the Hotellings T2 (T squared) distribution should be used.
I cannot find a function for