Displaying 20 results from an estimated 300 matches similar to: "Distance matrix by cosine?"
2002 Jan 27
1
DBM databases for R?
Hello!
Can I use DBM databases (as they are used in Perl) for the import of
large datasets in R?
Thanks in advance for your help,
Petra Steiner
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---------------------------------------------------
Petra Steiner
Arbeitsbereich Linguistik
Universitaet Muenster
Huefferstrasse 27
48149 Muenster
2002 Mar 26
1
comparing row by row in matrix
I don't know the Russell-Rao coefficient but maybe this will help:
You can compute the number of times y and x are both 1 (that's what your
function f does) by counting 1s in y*x, i.e., sum(y*x), aka t(y)%*%x.
Ordinary matrix multiplication does this row-by-column, so if M and N are
two binary matrices, M%*%t(N) will have (i,j) entry equal to the count of 1s
in common to row i of M and
2002 Jan 25
1
Fw: Summary for Distance matrix by cosine?
Dear all,
below you find enclosed my message from January 9th and my program
(attention: beginner).
Thanks for both answers! a. However, as far as I know the cosine is not the
same as the Pearson correlation (only in special cases).
b. Reid Huntsinger's hint was very useful, however I had to transpose the
matrix first, for I want to calculate the distance of the _rows_.
Regards,
Petra
2004 Jun 10
2
question about hierclust {multiv}
my major is bioinformatics, and i'm trying to cluster ( agglomerate
the closest pari of observations ) in R.
i have already got my own similarities metric, but do not know how to
clust it based on similarities instead of dissimilarities.
since the help document of hierclust mentions the parameter "sim",
which seems good to me, but it doesn't appear in the code of
hierclust()
2004 Jun 10
1
question about similarities cluster using hierclust
my major is bioinformatics, and i'm trying to cluster ( agglomerate
the closest pari of observations ) in R.
i have already got my own similarities metric, but do not know how to
clust it based on similarities instead of dissimilarities.
since the help document of hierclust mentions the parameter "sim",
which seems good to me, but it doesn't appear in the code of
hierclust()
2000 Aug 31
2
Multiv / hierclust / plclust
I use hierclust (hierarchical clustering) in multiv package. In the
documentation it is said that plclust (plotting a dendrogram) is
available in S-plus. Can I find it anywhere (I have searched through
http://lib.stat.cmu.edu/S and found only quotations of plclust in
multiv) or is it only part of the S package (which I don't have)?
Thanks
---------------
Charles RAUX,
Laboratoire
2003 Feb 09
3
Clustering partition and memory
Dear R-help list members
i would like to use R to produce clustering or partitioning of a dataset.
I am trying to use the functions:
- hierclust() of the package multiv
-pam(), agnes() and fanny() of the package cluster
But I cannot get any result because of lack of memory. Would you know any
clustering function not to greedy in memory?
I have tried to expand my memory limit with memory.limit()
2007 Oct 31
3
Find A, given B where B=A'A
Given a matrix B, where B=A'A, how can I find A?
In other words, if I have a matrix B which I know is another matrix A times
its transpose, can I find matrix A?
Thanks,
Mike
1998 May 29
1
R-beta: multiv package from CRAN
Hallo Friedrich,
I have read your announcement, downloaded and installed it in R-0.61.3.
But now I have problems :)
> hc <- hierclust(dist(t(pollen)), method=3)
Error in pmatch(x, table) : argument is not of mode character
> hc <- hclust(dist(t(pollen)))
> members(hc)
Error in .Fortran("assgn", n = as.integer(n), nplus1 =
as.integer(nplus1), : C/Fortran function not in
2003 Sep 26
1
a. crossing branches with hclust, b. plot.dendrogram
Hello,
a. when I use hclust with the methods media, centroid, and mcquitty,
and plot the results, the dendrograms have lines that are crossing each
other. Is this ok?
b. My next question refers to plot.dendrogram: How can I use parameters
as "hang" or "cex" here? E.g. for
st <- as.dendrogram(subtreeshc[[x]])
I would like to have something like this, where cex and hang
2003 Feb 13
2
How to solve A'A=S for A ?
Dear R helpers,
is there a function or way within R to solve A'A=S for A, where all
matrices have p x p order and S is a variance-covariance matrix?
Thank you,
Ralf Engelhorn
2003 Feb 14
2
How to solve A'A=S for A
It is not clear to me that one can. If the singular value decomposition
of A is the triple product P d Q', then the singular value decomposition
of A'A=S is Q d^2 Q'. The information about the orthonormal matrix P is
lost, is it not?
**********************************************************
Cliff Lunneborg, Professor Emeritus, Statistics &
Psychology, University of Washington,
2006 Jul 22
2
projection utility in ArcView
Hello to all, I am using ArcView 3.2 under Wine. For now I have been
able to do what I need, except for the projection utility... it seems
that I am missing some dll, but I have no clue which ones could be... If
somebody knows the solution, please let me know. I am new to Wine, and
have no clue how to search for the right dll...
Thanks a lot to all of you and to this great Wine-project!!!
Petra
2010 Nov 10
2
prcomp function
Hello,
I have a short question about the prcomp function. First I cite the
associated help page (help(prcomp)):
"Value:
...
SDEV the standard deviations of the principal components (i.e., the square
roots of the eigenvalues of the covariance/correlation matrix, though the
calculation is actually done with the singular values of the data matrix).
ROTATION the matrix of variable loadings
2012 Jan 10
4
Sum of a couple of variables of which a few have NA values
Dear everyone,
I have looked all over the internet but I cannot find a way to solve my problem.
In my data I want to sum a couple of variables. Some of these
variables have NA values, and when I add them together, the result is
NA
dat <- data.frame(
id = gl(5,1),
var1 = rnorm(5, 10),
var2 = rnorm(5, 7),
var3 = rnorm(5, 6),
var4 = rnorm(5, 3),
var5 = rnorm(5, 8)
)
dat[3,3] <- NA
dat[4,5]
2005 Aug 25
1
box m-test
Hello everybody,
Is there in R a so called box m-test for testing the equality of the
variance/cov. matrix for checking on homoscedasticity? I could not find
it among the traditional packages for multivariate statistics...
Petra
--
Petra Wallem
Centro de Estudios Avanzados en Ecolog伱伃a & Biodiversidad (CASEB)
Departamento de Ecolog伱伃a
Facultad de Ciencias Biol伱伋gicas
Pontificia
2005 Dec 26
3
factorial anova
Hello every body, I am trying to do a factorial anova analysis
following this model:
model<-anova(lm(responsevariable~factorA*factorB))
model<-anova(lm(luz$dosel~luz$estado*luz$Bosque))
Df Sum Sq Mean Sq F value Pr(>F)
estado 1 6931.1 6931.1 41.6455 7.974e-06 ***
Bosque 1 36.6 36.6 0.2197 0.6456
estado:Bosque 1 36.6 36.6 0.2197 0.6456
Residuals
2002 Apr 07
3
German umlaut in xlab
Dear all,
which font do I have to choose to use German umlauts at x/ylab in plot? Do I
have to change Rdevga; and how? Or should I use these Hershey vectors?
I looked quite a long time for a solution, which should be easy, so I
thought I'd better ask here.
Maybe some other people have already solved this problem.
Regards,
Petra
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Petra
2003 Jan 17
2
Linux permissions vs Samba permissions
Okay, admittedly I'm running an old version 2.0.5, but, why do I have to set
the eXecute permission in Linux before Samba will let a Windows client see
any files? Why would execute have anything to do with read and/or write? I
would think I could set -rw-rw---- or -rw-rw-rw- and be just fine, but oh
no, you get an empty list and cannot create new files until I change it
to -rwxrwx--- or
2001 Nov 29
2
memory issue trying to solve too large a problem using hclust
Hi, all.
I'm trying to cluster 12,500 objects using hclust from package mva. The
distance matrix takes up nearly 600 MB. The distance matrix also needs to
be copied when being passed to the fortran routine that actually does the
clustering (it's modified during the clustering), so that's 1200 MB. I'm
actually on a machine with 2.5 GB of memory (and nothing else running), so I