Displaying 20 results from an estimated 7000 matches similar to: "Minimum Spanning Trees"
2009 Apr 07
2
Minimum Spanning Tree
Hi all, I'm very new to R and read a few tutorials, however I'm having
difficulty trying to figure out how to plot a minimum spanning tree. I have
a csv file that contains an n-by-n matrix of distances between strains of
bacteria called matrix.csv.
Looks like:
id,strain1, strain2,strain3
strain1,0,.2,.8
strain2,.3,0,.7
strain3,.4,.6,0
I've been messing around with some information
2006 Mar 01
2
Weighted networks and multigraphs
I would like to apply network measures (such as betweenness centrality,
upper boundedness, etc.) to a weighted graph with non-integer weights,
defined by a euclidean distance matrix. The package sna provides the
measures that I want to use, but seems only to operate on binary graphs.
I have read work by Mark Newman
(http://aps.arxiv.org/abs/cond-mat/0407503/), who suggests that a
weighted graph
2002 Jan 21
1
[R-1.4.0] minimum spanning tree of large ontology
Dear all,
I have an ontology which I would like to load in R to then compute the
minimum distance between elements.
Since this ontology is not only DAG, the problem is non trivial and
therefore decided to use R with the powerful e1071
library (allShortestPaths) to do that. That method requires to provide a
distance matrix between the
various objects. My ontology contains 32768 objects and
2010 May 13
2
need help in igraph package of R
hi
I am struck with a problem in igraph package of R. My problem is as follows
I want to plot a power law fit for my data (in .net format --- pajek format)
syntax for that in R is
g <- read.graph("filename.net", "pajek")
d <- degree (g, mode="in")
power.law.fit (d+1, 2)
it gives me desired out put if my if input a single file
but I want to use a variable
2009 Sep 11
2
Graph visualization
Hello,
I am working with graph and adjacency matrix, the package 'graph' seems to be appropriate for this.
An example in the package
> mat <- rbind(c(0, 0, 1, 1),
+ c(0, 0, 1, 1),
+ c(1, 1, 0, 1),
+ c(1, 1, 1, 0))
> rownames(mat) <- colnames(mat) <- letters[1:4]
> graph1 <- new("graphAM", adjMat=mat)
> graph1
A
2002 May 07
0
clustering: single linkage path in minimum spanning tree
My understanding is that single linkage clustering is equivalent to
finding the minimum spanning tree. Hclust works very nicely for finding
the clusters but I am unable to find enough information in its output to
construct the minimum spanning tree. In particular, I want to find a
minimum spanning tree path between two items in the tree. Is this
possible with hclust or is there another
2009 Nov 16
3
Discontinuous graph
Hi,
I wanted to make a graph with the following table (2 rows, 3 columns):
a b c
x 1 3 5
y 5 8 6
The first column represents the start cordinate, and the second column contains the end cordinate for the x-axis. The third column contains the y-axis co-ordinate. For example, the first row in the matrix above represents the points (1,5),(2,5), (3,5). How would I go about making a discontinuous graph
2004 Aug 19
3
Do you know if you can map a large minimum spanning tree in R?
Thanks Mike.
My data has longitude and latitude coords and I used distAB {clim.pact}
then mst {ape} to calculate my minimum spanning tree. The nodes are
telecoms sites from all over Australia. My goal is to determine the
minimum cost of linking them via cabling, and I'm starting by
calculating the distance "as the crow flies", but will probably
eventually need to calculate the
2011 Sep 05
2
Need more information about VGLM
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URL : <https://stat.ethz.ch/pipermail/r-help/attachments/20110905/43ff838a/attachment.pl>
2010 May 05
3
Symbolic eigenvalues and eigenvectors
Let's say I had a matrix like this:
library(Ryacas)
x<-Sym("x")
m<-matrix(c(cos (x), sin(x), -sin(x), cos(x)), ncol=2)
How can I use R to obtain the eigenvalues and eigenvectors?
Thanks,
John
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2011 Mar 24
2
Using C code in R
Hi,
I am new to R and I want to know how to use C code which contains two
functions one called inside another.I know that how to use C code in R if it
has only one function but dont know how to do it in above case. I want to
use the same in R .My C code is as follows.
//#include <R.h>
void sayHello();
void g();
void sayhello() {
Rprintf("Hello world %d\n",global);
}
void
2006 Mar 01
1
Drop1 and weights
Hi,
If I used drop1 in a weighted lm fit, it seems to ignore the weights
in the AIC calculation of the dropped terms, see the example below.
Can this be right?
Yan
--------------------
library(car)
> unweighted.model <- lm(trSex ~ (river+length +depth)^2-
length:depth, dno2)
> Anova(unweighted.model)
Anova Table (Type II tests)
Response: trSex
Sum Sq Df F value
2010 Jul 20
1
Servreg $loglik
Dear R-experts:
I am using survreg() to estimate the parameters of a Weibull density having
right-censored observations. Some observations are weighted. To do that I
regress the weighed observations against a column of ones.
When I enter the data as 37 weighted observations, the parameter estimates
are exactly the same as when I enter the data as the corresponding 70
unweighted observations.
2008 Aug 24
3
Igraph library: How to calculate APSP (shortest path matrix) matrix for a subset list of nodes.
Dear R Users,
I have a network of 25000 total nodes and a list of 500 node which is a
subset of all nodes. Now I want to calculate the APSP (all pair shortest
path) matrix only for these 500 nodes.
I would appreciate any help.
Thanks in advance
Dinesh
--
Dinesh Kumar Barupal
Research Associate
Metabolomics Fiehn Lab
UCD Genome Center
451 East Health Science Drive
GBSF Builidng
University of
2010 Jan 21
2
How to open .rda file in R
Hi,
I have a file containing gene expressions written using the tillingArray package. I used load() and attach() to get the data into R. Both of them works fine. Now I want to see the contents of the file. How can I see the contents of the file?
Thankyou for your time.
Regards,
Ambuj
The INTERNET now has a personality. YOURS! See your Yahoo! Homepage.
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2010 Jun 14
2
Multiple regressions
Hi,
Could you please tell me whether SVM can do multiple regression or not?
Cheers,
Amy
_________________________________________________________________
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2010 Sep 23
2
hdf-files
Dear All,
I have data in HDF file format and would like to read it into R.
I have tried the package hdf5 without success.
Any ideas and suggestions??
Kind regards,
Katrin
--
Katrin Fleischer
Vrije Universiteit Amsterdam
Faculty of Earth and Life Sciences
Subdepartment Hydrolgy and Geo-Environmental Sciences
Room E-360
De Boelelaan 1085
1081 HV AMSTERDAM
Tel: +31 20 59 87391
2012 Feb 20
2
R
Hello, just a couple of short questions that would be much appreciated.
Is there a way of putting a vectors inputs in size order from low to high?
And if I had a random list or TRUE and FALSE, is there a way of finding the 100th TRUE?
Thank you very much,
Elliot Welch
elliot.welch at virgin.net
Sent from my BlackBerry? smartphone
2012 Oct 10
2
history() does not work?
Hi,
> history()
gives Error in savehistory(file) : no history available to save
although I can scroll throu history with C^uparrow an C^downarrow.
How can I make history() work and/or show the current history in a file,
so that I can choose from previous commands?
The web did not throw up anything useful.
TIA --Christian
--
Christian W. Hoffmann,
CH - 8915 Hausen am Albis,
2010 Jun 16
2
Parallel computing on Windows (foreach) (Sergey Goriatchev)
foreach (or virtually anything you might use for concurrent programming)
only really makes sense if the work the "clients" are doing is substantial
enough to overwhelm the communication overhead. And there are many ways to
accomplish the same task more or less efficiently (for example, doing blocks
of tasks in chunks rather than passing each one as an individual job).
But more to the