Displaying 20 results from an estimated 9000 matches similar to: "Computing the mode"
2004 Jul 12
3
Smooth monotone estimation on R
Hi all,
I'm looking for smooth monotone estimation packages, preferably using splines.
I downloaded the 'cobs' package and intend to use it, but since it offers only quadratic splines based on L1 minimization, I'd like to compare its performance to that of a more 'mainstream' cubic-spline, L2-norm minimizing spline. Preferably a smoothing spline.
Does anyone know of such
2006 Sep 22
4
Creating Movies with R
Dear All,
I'd like to know if it is possible to create animations with R.
To be specific, I attach a code I am using for my research to plot
some analytical results in 3D using the lattice package. It is not
necessary to go through the code.
Simply, it plots some 3D density profiles at two different times
selected by the user.
I wonder if it is possible to use the data generated for different
2004 Dec 09
2
Peak finding algorithm
I'm sure there must be various peak-finding algorithms out there. Not
knowing of any, I have written one myself*, but I thought I'd ask to
see what's out there.
Basically, I have a 2-dimensional data set and I want to identify local
peaks in the data, while ignoring "trivial" peaks. My naive algorithm
first identifies every peak and valley (point of inflection change
2005 Mar 03
1
total variation penalty
Hi,
I was recently plowing through the docs of the quantreg package by Roger
Koenker and came across the total variation penalty approach to
1-dimensional spline fitting. I googled around a bit and have found some
papers originated in the image processing community, but (apart from
Roger's papers) no paper that would discuss its statistical aspects.
I have a couple of questions in this
2006 Apr 23
3
bivariate weighted kernel density estimator
Is there code for bivariate kernel density estimation?
For bivariate kernels there is
kde2d in MASS
kde2d.g in GRASS
KernSur in GenKern
(list probably incomplete)
but none of them seems to accept a weight parameter
(like density does since R 2.2.0)
--
Erich Neuwirth, University of Vienna
Faculty of Computer Science
Computer Supported Didactics Working Group
Visit our SunSITE at
2008 Dec 03
1
function qt can fails if ndf < 1 (PR#13364)
Full_Name: Gerard Torrent
Version: R version 2.8.0 (2008-10-20)
OS: Linux 2.6.27.5-41.fc9.x86_64 #1 SMP
Submission from: (NULL) (85.52.227.233)
In some cases qt complains about NaNs and don't gives the correct result:
> qt(0.1,, 0.1)
[1] NaN
Warning message:
In qt(p, df, lower.tail, log.p) : NaNs produced
But the result can be found:
> pt(-1.60443e+06, 0.1)
[1] 0.09999997
If I
2005 May 13
2
help with texi2dvi
Hello,
Does anyone know how to write the files created by the call of
"texi2dvi" in another directory ?
Thanks,
Matthieu
2003 Nov 03
5
comparing characters
Hi all,
I?m having some trouble when trying to compare character values (to
check if they are alphabetically ordered). Is it possible to do it in
any way?
Thanks for your help. Cheers,
Aurora
2003 Mar 26
3
hist overlay...
thanks to all for the 2d scatter plot.
i have one more.
how do i plot 'hist(y1, col="red") and hist(y2,col="blue") in the same window?
thanks again.
2007 Oct 04
3
Contour plot (level curves)
Hi all,
I have a sample of n values from a bivariate distribution (from a MCMC
procedure). How could I draw a contour plot of "the joint density" based on
that sample ?
Sorry if I was not too clear.
Thans in advance,
Regards,
Caio
[[alternative HTML version deleted]]
2011 Feb 28
3
re-arranging data to create an image (or heatmap)
Let me start by introducing myself as a biologist with only a little
knowledge about programming in matlab and R. In the past I have succesfully
created my figures in matlab using the hist3d command, but I have not access
to matlab right now and would like to switch to R.
I have used the plot command to create a figure of my data and it does
almost what I want it to do.
My data matrix looks like
2006 Jan 19
2
function kde2d
Good evening,
I am Marta Colombo, student at Milan's Politecnico.
Thank you very much for your kindness, this mailing list is really useful.
I am using the function kde2d for two-dimensional kernel density estimation and I'd like to know something more about this kind of density estimator. In particular I'd like to know: what bandwidth is used ?
Thank you in advance for your attention
2006 Jun 14
1
Estimate region of highest probabilty density
Estimate region of highest probabilty density
Dear R-community
I have data consisting of x and y. To each pair (x,y) a z value (weight) is assigned. With kde2d I can estimate the densities on a regular grid and based on this make a contour plot (not considering the z-values). According to an earlier post in the list I adjusted the kde2d to kde2d.weighted (see code below) to estimate the
2007 Dec 11
1
R computing speed
Dear helpers,
I am using R version 2.5.1 to estimate a multinomial logit model using my
own maximum likelihood function (I work with share data and the default
function of R cannot deal with that).
However, the computer (I have an Athlon XP 3200+ with 512 GB ram) takes
quite a while to estimate the model.
With 3 categories, 5 explanatory variables and roughly 5000 observations it
takes 2-3 min.
2005 Jan 09
2
How can I simulate Pareto distribution in R?
Hi, guys,
I need to simulate Pareto distribution. But I found 'rpareto' didn't exist in R. And it seems that Pareto distribution don't have mathematical relationships with other distributions. What can I do?
Thanks a lot.
Ni
---------------------------------
[[alternative HTML version deleted]]
2002 Apr 03
2
Peer-to-peer audio codec
A friend and I were recently talking about the possible
downfall of Internet radio, and as everyone seems to these days, decided
that a nice solution would be to set up a P2P broadcasting solution.
However, streaming has a completely different set of requirements than
file sharing, with bandwidth and QOS become much larger issues. As such,
we started to realize that a new audio compression scheme
1999 Oct 08
1
floor(NaN) problem fixed in massdist.c (PR#291)
Full_Name: Naoki Takebayashi
Version: 0.65.0+R-release.diff (Oct 6, 1999)
OS: Linux/Alpha
Submission from: (NULL) (129.79.224.171)
This will fix the "problem 2 (crash in fft)" in Bug ID #277
On Linux/Alpha, make check failed because R could not handle the following
example in base-Ex.R
##___ Examples ___:
# The Old Faithful geyser data
data(faithful)
:
:
## Missing values:
x <-
2003 Nov 14
2
Round error?
Hi all,
I have tried to compute a p-value for a hypergeometric distribution as:
dhyper(x,k,l,n) + phyper(x,k,l,n,lower.tail=FALSE)
and sometimes obtained negative values. Do you know if it is because a
round error or am I doing something wrong?
Thanks in advance,
Aurora
2005 Nov 07
2
how to export density_function output?
Dear all,
quite a naive question: I have a data frame and I computed "the kernel
density estimate" with density on each column.
Now I'd like to export in a txt file the density function output for each
column, but, when if I use write.table, I get a message "Error in
as.data.frame.default(x[[i]], optional = TRUE) : can't coerce class
"density" into a
2010 Mar 30
1
hist.default()$density
Dear developers,
the current implementation of hist.default() calculates 'density' (and
'intensities') as
dens <- counts/(n*h)
where h has been calculated before as
h <- diff(fuzzybreaks)
which results in 'fuzzy' values for the density, see e.g.
> tmp <- hist(1:10,breaks=c(-2.5,2.5,7.5,12.5),plot=FALSE)
> print(tmp$density,digits=15)
[1]