Displaying 20 results from an estimated 10000 matches similar to: "How to draw 4 random weights that sum up to 1?"
2006 Oct 10
4
generate random numbers that sum up to 1
As I have previously asked, in response to a similar
question: Is this a homework problem?
cheers,
Rolf Turner
rolf at math.unb.ca
2012 Nov 07
6
how to generate a set of random numbers that sum to 1 with uniform distribution of elements
Hi,
I am looking for a way to generate a matrix of random numbers in a way that
each row of the matrix would sum to 1 and that the numbers in the columns of
the matrix would have a uniform distribution. So far I have found several
ways to create random numbers that would sum to 1, but then the distribution
of the individual elements is more or less skewed - there are much more
small numbers than
2008 Nov 23
2
Latin Hypercube with condition sum = 1
Hi
I want to du a sensitivity analysis using Latin Hypercubes. But my
parameters have to fulfill two conditions:
1) ranging from 0 to 1
2) have to sum up to 1
So far I am using the lhs package and am doing the following:
library(lhs)
ws <- improvedLHS(1000, 7)
wsSums <- rowSums(ws)
wss <- ws / wsSums
but I think I can't do that, as after the normalization
> min(wss)
[1]
2006 Jul 19
2
voronoi tessellations
Okay, been working with tripack, seems the most mature package for this. Got it to work well with their test data set - data(tritest). When i tried random numbers to explore further, i am getting some results that don't reconcile.
example run this:
library(tripack)
y <- runif(100)
x <- runif(100)
vm <- voronoi.mosaic(x,y)
plot(vm)
par(new=T)
plot(x,y,col='blue')
when
2011 Mar 29
4
Creating 3 vectors that sum to 1
I have 3 vectors: p1, p2, and p3. I would like each vector to be any
possible value between 0 and 1 and p1 + p2 + p3 = 1. I want to graph these
and I've thought about using scatterplot3d(). Here's what I have so far.
library(scatterplot3d)
p1 <- c(1,0,0,.5,.5,0,.5,.25,.25,.34,.33,.33,.8,.1,.1,.9,.05,.05)
p2 <- c(0,1,0,.5,0,.5,.25,.5,.25,.33,.34,.33,.1,.8,.1,.05,.9,.05)
p3 <-
2011 Feb 24
1
weighted Voronoi diagrams
Dear R-users,
Does anyone know how to do weighted Voronoi diagrams (Dirichlet
tesselation) in R? To be more specific, I have a set of coordinates for
tree locations on a plot, and I'm looking for a way to do the
tesselation so that the polygon size for each tree depends on the size
of the subject tree, and the size of its neighbors. So, the location of
the bisection between two trees
2007 Mar 24
2
sampling from the unoform distrubuton over a convex hull
Dear list,
Does anyone have a suggestion (or better still) code for sampling from the uniform distribution over the convex hull of a set of points?
Many thanks and best wishes,
Ranjan
2006 Sep 18
1
Simulation of a Dirichlet Process.
I'm just getting started with R, having a lot of original work on
modeling and exploring the simulation by MCMC. I want to simulate the
prior and the posterior distribution of Dirichlet Process by MCMC.
Is there anyone in NYC that might be a good
tutor for me?
--
Dr. P. NGOM,
Facult? des Sciences et Techniques
D?partement de Math?matiques et Informatique
Universit? Cheikh Anta Diop Dakar -
2024 Sep 14
1
Dirichlet kernel requires r to be defined, which is not in the help
Code to reproduce
> kernel("dirichlet")
Error in kernel("dirichlet") : argument "r" is missing, with no default
The help says
r??? the kernel order for a Fejer kernel.
Thanks to update the help.
Best,
Samuel
2016 Jul 24
2
Weighting Schemes: Evaluation results
Hi all,
I have evaluated new weighting schemes along with their existing
counterparts in Xapian to compare and see which one does better job.
Also, I have put together all the results files for easy access here:
https://github.com/ivmarkp/xapian-evaluation/tree/evaluation/run
and a README for getting started with xapian-evaluation module. Hopefully,
it might be of help to those who are new to
2007 Jul 10
2
integration over a simplex
Hello
The excellent adapt package integrates over multi-dimensional
hypercubes.
I want to integrate over a multidimensional simplex. Has anyone
implemented such a thing in R?
I can transform an n-simplex to a hyperrectangle
but the Jacobian is a rapidly-varying (and very lopsided)
function and this is making adapt() slow.
[
A \dfn{simplex} is an n-dimensional analogue of a triangle or
2005 Feb 28
1
draw random samples from empirical distribution
Dear useRs,
I have an empirical distribution (not normal etc) and I want to draw
random samples from it. One solution I can think of is to compute let's
say 100 quantiles, then use runif() to draw a random number Q between 1
and 100, and finally run runif() again to pull a random value from the
quantile Q. Is there perhaps a better/more elegant way of doing this?
Thank you,
b.
2011 Mar 29
1
Dirichlet surface
Dear list members,
I want to draw surfaces of Dirichlet distributions with different
parameter settings.
My code is the following:
#<begin code>
a1 <- a2 <- a3 <- 2
#a2 <- .5
#a3 <- .5
x1 <- x2 <- seq(0.01, .99, by=.01)
f <- function(x1, x2){
term1 <- gamma(a1+a2+a3)/(gamma(a1)*gamma(a2)*gamma(a3))
term2 <- x1^(a1-1)*x2^(a2-1)*(1-x1-x2)^(a3-1)
2006 Sep 19
1
help on dirichlet distribution
Dear Gregory R. Warnes,
I'm a phd student in statistics, at the University of Milano Bicocca.
I'm interested to the methods of estimate the parameters of the Dirichlet distribution.
Do you have implemented an algorithm in R?
If so, can you give me the script? or, in general, some helps?
Best Regards
Gianna
---------------------------------------------------------------
Gianna Monti
2009 Dec 09
3
Plotting frequency curve over histogram
Hello,
This is a problem for which there seem to be several solutions online, but
not really. My question was about plotting a curve over the histogram. All
the previous posts and messages talk about generating a *density
histogram*using (freq=F) and then plotting the density curve. However,
I find that
that seriously distorts my data and the plot becomes confounding to the
viewer.
I was
2013 May 12
1
Multinomial-Dirichlet using R
Hi:
I have asked this question on Cross-Validated. So it might be a cross
posting but havent received any responses to it.
I am trying to see which distribution will best fit the data I am working
on. The dataset is as following:
Site Nausea headache Abdominal Distension
1 17 5 10
2 12
2010 Sep 15
3
Creating publication-quality plots for use in Microsoft Word
Hi everyone,
I am trying to make some publication-quality plots for use in Microsoft
Word, but I am having trouble creating high-quality plots that are supported
by Microsoft Word.
If I use the R plot function to create the figure, the lines are jagged, and
the picture is not of high quality (same with JPEG(), TIFF(), and PNG()
functions). I have tried using the Cairo package, but it distorts
2010 Aug 27
2
multivariate distributions
Hi,
How can I generate data from multivariate gamma distribution & multivariate
beta distribution?
I only found command for multivariate normal only.
Many thanks in advance :)
Regards
Rofizah
[[alternative HTML version deleted]]
2011 Mar 03
2
[Bug 706] Iptables randomly reject some packets that have accept rule
http://bugzilla.netfilter.org/show_bug.cgi?id=706
Jan Engelhardt <jengelh at medozas.de> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jengelh at medozas.de
--- Comment #1 from Jan Engelhardt <jengelh at medozas.de> 2011-03-03 14:20:30
2003 Sep 09
1
Should Speex VBR Introduce Distortion?
Hi All,
I've run into a small hiccup in encoding my audios with Speex. When I
encode audience laughter and applause with 'speexenc' (version 1.0.1),
the result is quite acceptable... until I enable VBR. Then it distorts
horribly.
My understanding of VBR is that it frees the encoder to vary the number
of bits emitted to better maintain the quality requested, and so I would
have