Displaying 20 results from an estimated 270 matches similar to: "Kernel Density Estimation at manually specified points"
2003 Sep 26
2
performance question
Hi,
I am about to write functions for multivariate kernel densitiy estimation
with mixed categorical and continuous date (accoring to Jeff Racine and Qi
Li), and the leave-one-out window esitmation needs a lot of computation.
I am now optimizing the code performance and therefore fhe following
questions:
As R uses call-by-value for functions, is it computational expensive to pass
large matrices
2007 May 01
2
Simulation using parts of density function
Hi
My simulation with the followin R code works perfectly:
sim <- replicate(999, sum(exp(rgamma(rpois(1,2000), scale = 0.5, shape = 12))))
But now I do not want to have values in object "sim" exceeding 5'000'000, that means that I am just using the beginning of densitiy function gamma x < 15.4. Is there a possibility to modify my code in an easy way?
Thanks for any help!
2007 Apr 02
3
Random number from density()
Hello,
I'm writing some genetic simulations in R where I would like to place
genes along a chromosome proportional to the density of markers in a
given region. For example, a chromosome can be presented as a list of
marker locations:
Chr1<-c(0, 6.5, 17.5, 26.2, 30.5, 36.4, 44.8, 45.7, 47.8, 48.7, 49.2,
50.9, 52.9, 54.5, 56.5, 58.9, 61.2, 64.1)
Where the numbers refer to the locations of
2010 Feb 05
1
Using coxph with Gompertz-distributed survival data.
Dear list:
I am attempting to use what I thought would be a pretty straightforward practical application of Cox regression. I figure users of the survival package must have come across this problem before, so I would like to ask you how you dealt with it. I have set up an illustrative example and included it at the end of this post.
I took a sample of 100 data points from each of two populations
2012 Jul 17
1
about different bandwidths in one graph
Thank you in advance.
Now I want to make comparison of the different bandwidth h in a normal
distribution graph.
This is the table of bandwidth h: thumb rule (normal)--0.00205; thumb
rule(Epanech.)--0.00452; Plug-in (normal)--0.0009;
Plug-in(Epanech.)--0.002.
this is the condition: N=1010 data sample is from normal distribution
N(0,0.0077^2). The grid points are taken to be [-0.05,0.05] and
2016 Apr 22
1
npudens(np) Error missing value where TRUE/FALSE needed
Hi,
I am looking for some help concerning the npudens function
in the np package.
I am trying to find a kernel density function of a
multivariate dataset and the density evaluated at each of the 176 points.
I have 2 continuous and 3 ordered discrete variables. My
sample size is 176.
So edata is a 176x(2+3) data frame, while tdat is a 1x(2+3)
vector.
bw_cx[i,] is a 1x (2+3) vector
1999 Dec 01
1
density(kernel = "cosine") .. the `wrong cosine' ..
I'm in teaching mode, kernel densities.
{History: density() was newly introduced in version 0.15, 19 Dec 1996;
most probably by Ross or Robert
}
When I was telling the students about different kernels (and why their
choice is not so important, and "equivalent bandwidths" etc,etc)
I wondered about the "Cosine" in my teaching notes which
is defined there as
k(x)
2010 Jun 01
1
BreastCancer Dataset for Classification in kknn
Dear All,
I'm getting a error while trying to apply the BreastCancer dataset
(package=mlbench) to kknn (package=kknn) that I don't understand as I'm new
to R.
The codes are as follow:
rm = (list = ls())
library(mlbench)
data(BreastCancer)
library(kknn)
BCancer = na.omit(BreastCancer)
d = dim(BCancer)[1]
i1 = seq(1, d, 2)
i2 = seq(2, d, 2)
t1 = BCancer[i1, ]
t2 =
2008 Feb 07
1
User-defined Kernels
Hi,
i would like to do a local linear regression but with a user-defined
function f(x,y) as kernel.
(not the typical Gaussian or Epanechnikov kernel function but some similar
function).
More, would it be possible to do a local linear regression by adding weights
to the (x,y) data points?
Many thanks in advance.
--
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2009 Jun 03
0
Treated - KernSmooth pckg - dpik function gives numeric(0) for kernel="epanech"
Epanechnikov kernel works if option canonical=TRUE, however it would
be good to know why it does not for for canonical=FALSE (default).
Sorry for craetaing maybe useless thread.
Best regards,
Ondra.
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2011 Jul 20
0
np package, KleinSpady estimator, error when I estimate the bootstrapped standard errors
Dear all,
I am using np package in order to estimate a model with Klein and Spady
estimator. To estimate the model I use
KS <- npindexbw (xdat=X, ydat=Y, bandwidth.compute=TRUE,
method="kleinspady", optim.maxit=10^3, ckertype="epanechnikov", ckerorder=2)
and to estimate beta hats standard errors I use
KSi <- npindex(KS, gradients=T, boot.num=300)
vcov(KSi)
This is
2011 Jul 25
0
error in optimization when I include constant term in Klein and Spady (np package)
Dear all,
I am trying to use the np package for the estimation of a model with Klein
and Spady's semiparametric estimator. When though, I include a constant term
( a column with 1s in X) then the following message appear:
Multistart 1 of 3...Error in optim(c(beta, h), fn = optim.fn, gr = NULL,
method = optim.method, :
non-finite value supplied by optim
So, how can I include a constant
2010 Jul 24
0
local polynomial with differnt kernal functions
Hi, R users
I need to use the function (locpoly) to fit a local poynomial regression model, The defult for kernal function is " normal" , but I need to use different kernal functions such as :Uniform,Triangular,Epanechnikov,......
Could someone help me define these functions to fit local polynomial regression model?.
Email:assaedi76@yahoo.com
Thanks alot
[[alternative
2005 May 12
0
Package adehabitat version 1.3
Dear all,
I have just uploaded to CRAN the version 1.3 of the
package 'adehabitat'. Significant changes are
listed below:
- Several functions allowing the conversion from
and to classes of the package sp have been added.
Maps of class "asc", "kasc", "area", as well as
radio-monitoring of class "traj" can now be
converted to the spatial
2005 May 12
0
Package adehabitat version 1.3
Dear all,
I have just uploaded to CRAN the version 1.3 of the
package 'adehabitat'. Significant changes are
listed below:
- Several functions allowing the conversion from
and to classes of the package sp have been added.
Maps of class "asc", "kasc", "area", as well as
radio-monitoring of class "traj" can now be
converted to the spatial
2011 Jan 26
0
baseline hazard function
Dear colleagues, I have the following dataset. It is modelled on the data included in Box-Seteffenheiser and Jones "Event History Modelling"
Using the following code, I try to find the baseline hazard function
haz_1<-muhaz(bpa$time, bpa$censored, subset=(bpa$year=="2010" | bpa$ban=="1"), min.time=1, max.time=3)
I think I'm doing everything right, but what I
2011 Jul 18
0
np package, estimating the standard errors of Klein and Spady's estimator
Dear all,
I would like to estimate the standard errors of Klein and Spady's estimator
for that I am using:
library(np)
N<-100
X<-matrix(c(rnorm(N,1,1), rnorm(N,0,1)), ncol=2)
BETA <-matrix(1,2,1)
Z<-X%*%BETA
L<-rlogis(N,location=0, scale=1)
Y <-as.vector(X%*%BETA+L>=0)*1
KS <- npindexbw (xdat=X, ydat=Y, bandwidth.compute=TRUE,
method="kleinspady",
2008 Jul 25
0
Package np version 0.20-0 released to CRAN
Dear R users,
An updated version of the np package has recently been uploaded to CRAN
(version 0.20-0). Version 0.20-0 is documented in
Tristen Hayfield and Jeffrey S. Racine (2008). Nonparametric
Econometrics: The np Package. Journal of Statistical Software 27(5). URL
http://www.jstatsoft.org/v27/i05/
and also in a vignette (vignette("np",package="np")). There is also a
FAQ
2008 Jul 25
0
Package np version 0.20-0 released to CRAN
Dear R users,
An updated version of the np package has recently been uploaded to CRAN
(version 0.20-0). Version 0.20-0 is documented in
Tristen Hayfield and Jeffrey S. Racine (2008). Nonparametric
Econometrics: The np Package. Journal of Statistical Software 27(5). URL
http://www.jstatsoft.org/v27/i05/
and also in a vignette (vignette("np",package="np")). There is also a
FAQ
2007 May 03
0
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