Displaying 20 results from an estimated 1000 matches similar to: "power law"
2009 Apr 06
5
Search for a graph package - see link
Hi to all,
does anybody knows whether there is a package to plot those
http://www.equine-science.de/temp/graph.jpg
graphs.
the thickness of the points and/or the lines should be represent the
numbers of behaviours
With kind regards Knut
2007 Jul 18
2
maximum likelihood estimation
Hello!
I need to perform maximum likelihood estimation on R, but I am not sure
which command to use. I searched on google, and found an example using the
function mlogl, but I couldn't find the package on R. Is there such
function? Or how should i perform my mle?
Thank you very much.
--
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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
2007 Sep 21
2
duplicated names and values
Dear list,
I am sorry about this simple question, but somehow I can not figure out
how to solve my problem, may be you could help?
I have a vector mir3:
> length(mir3)
[1] 220671
>head(mir3)
rno-miR-30c rno-miR-30c rno-miR-30d
rno-miR-30e "ENSRNOT00000049288" "ENSRNOT00000049288"
"ENSRNOT00000049288"
2009 Jan 18
1
about power.law.fit
Dear all,
I'm using igraph for some analysis about the network I have. I have a
question about the function "power.law.fit".
I wonder if there is any test for checking whether the "power.law.fit" is
good for the input, i.e., under which situation, could we use this function
to get a reliable result. I'm afraid even I input a random graph without any
property of
2007 Feb 09
1
extract submatrix with unique names
Dear list,
I have a table where first 3 columns are identical if the name in the
first column is the same, and
the number in N4 is slightly different for all identical names, like
this:
-------------------------------------------------------------------
29 Mm.1_at 3 + 93649936
30 Mm.1_at 3 + 93649990
31 Mm.1_at 3 + 93649993
32
2006 Feb 16
1
how to save the picture with par(mfrow = c(1, 3), pty='s') setti ngs?
Dear list,
I am trying to place 3 density functions in one Figure, 1 row by 3 columns:
-------------------------------------------------------
op <- par(mfrow = c(1, 3),pty='s')
pdf(file="Fig_den.pdf")
barplot2(tab.in,plot.grid=TRUE,xlab="number of HGT_in",ylab="density")
lines(dneg,col="red",lwd=2)
2006 Apr 28
1
Checking Goodness of Fit With Kolmogorov-Smirnov
Hi,
I'm using the power.law.fit function from the igraph package to fit a
power law distribution to some data. This function returns the power
law exponent as it's only result. I would like to have some sort of
goodness-of-fit and/or error estimate of the exponent returned. This
paper:
http://www.edpsciences.org/articles/epjb/pdf/2004/18/b04111.pdf
suggests using the
2007 May 09
3
Removing a list of Objects
Hi,
I have a simple beginner's question on removing a list of
objects. Say I have objects C243.Daily1, C243.Daily2...C243.Daily5 in my
workspace. I'd like to remove these without using rm five times.
So I write.
> a <- list(paste("C243.Daily",sep="",1:5))
> rm(a)
Obviously this wouldn't work, as it would only remove the object a.
But is there any way
2011 Nov 22
3
On-demand importing of a package
Dear All,
in some functions of my package, I use the Matrix S4 class, as defined
in the Matrix package.
I don't want to depend on Matrix, however, because my package is
perfectly fine without Matrix, most of the functionality does not need
Matrix. Matrix is so included in the 'Suggests' line.
I load Matrix via require(), from the functions that really need it.
This mostly works
2008 May 22
1
Computing Maximum Loglikelihood With "nlm" Problem
Hi,
I tried to compute maximum likelihood under gamma distribution,
using nlm function. The code is this:
__BEGIN__
vsamples<- c(103.9, 88.5, 242.9, 206.6, 175.7, 164.4)
mlogl <- function(alpha, x) {
if (length(alpha) > 1) stop("alpha must be scalar")
if (alpha <= 0) stop("alpha must be positive")
return(- sum(dgamma(x, shape = alpha, log = TRUE)))
2008 Feb 11
4
Conditional rows
Hi,
Given a simple example, test <- matrix(c(0.1, 0.2, 0.1, 0.2, 0.1, 0.1, 0.3,
0.1, 0.1), 3, 3)
How to generate row indexes for which their corresponding row values are
less than or equal to 0.2 ? For this example, row 2 and 3 are the correct
ones.
Thanks
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2007 Apr 18
3
Problems in programming a simple likelihood
As part of carrying out a complicated maximum likelihood estimation, I
am trying to learn to program likelihoods in R. I started with a simple
probit model but am unable to get the code to work. Any help or
suggestions are most welcome. I give my code below:
************************************
mlogl <- function(mu, y, X) {
n <- nrow(X)
zeta <- X%*%mu
llik <- 0
for (i in 1:n) {
if
2008 Jul 11
2
network
Hello
I am a relatively new user of R and am struggling to use the 'network' package. I have a correlation matrix (produced using 'cor'), and want to draw a network where each item showing correlation above a threshold (say 0.5) is joined by a green line, and each item showing correlation below a threshold (say -0.5) is joined by a red line. Does anyone have any hints of how to
2012 Aug 15
3
per-vertex statistics of edge weights
I have a graph with edge and vertex weights, stored in two data frames:
--8<---------------cut here---------------start------------->8---
vertices <- data.frame(vertex=c("a","b","c","d"),weight=c(1,2,1,3))
edges <-
2009 Jun 19
1
a difficulty in boot package
Hi,
I have a problem in programming for bootstrapping.
I don't know why it show the error message.
Please see my code below:
#'st' is my original dataset.
#functions of 'fml.mlogl','pcopula.fam4','ltd','invltd' are already defined
boot.OR<-function(data,i)
{
E=data[i,]
ml1<-glm(c_VAsex90_bf ~ trt,family=binomial,data=E)
ml2<-glm(c_VAsex90_bm ~
2008 Jan 11
2
Count unique rows/columns in a matrix
Dear List,
i know there are some solutions for this in the archive,
but they're not very good for numeric matrices, since they
usually convert rows/columns to character strings. Is there
an easy way to do $subject for numeric matrices properly,
or i need to do it by hand?
Thanks,
Gabor
2008 Jan 26
3
Which R version created a package?
Greetings, R-ians:
I would like to know which version or R was used to create a given package.
I think I remember seeing that topic discussed recently but cannot find it
among my notes. Can anyone tell me how to determine which version of R
created a package?
Thanks.
Charles Annis, P.E.
<mailto:Charles.Annis@StatisticalEngineering.com>
Charles.Annis@StatisticalEngineering.com
2008 Feb 01
2
re placing values in a matrix
useR's,
Consider:
y <- c(20, 25, 30)
> m <- matrix(c(0.0,1,NA,0.5,1.25,0.75, 0.5, NA,
> NA),byrow=TRUE,nrow=3,ncol=3)
> m
[,1] [,2] [,3]
[1,] 0.0 1.00 NA
[2,] 0.5 1.25 0.75
[3,] 0.5 NA NA
For each numeric value, I want to replace them with their corresponding
y-value. The result should look like (here, each row represents a variable
rather than the columns):
2007 Sep 14
6
replace NA value with 0
Hi,
how can I replace NA value with 0:
1991 217 119 103 109 137 202 283 240 146 NA
1992 270 174 149 144 166 239 278 237 275 NA
1993 146 111 104 89 98 131 153 148 175 NA
1994 177 123 146 124 121 200 266 191 240 106
1995 145 98 95 89 95 130 183 161 164 129
1996 145 98 89 90 93 138 158 131 161 161
1991 217 119 103 109 137 202 283 240 146 0
1992 270 174 149 144 166 239 278 237