Displaying 20 results from an estimated 40000 matches similar to: "Kernel distribution"
2004 Aug 30
3
D'agostino test
Hi, Does anyone know if the D'agostino test is available with R ?
Alex
2012 Feb 13
1
Cumulative density (kernel smoothing)
Hi, in R there is the function "density" which computes kernel density
estimates. Is there a "cumulative" version of it? Something like they have
in Matlab:
http://www.mathworks.nl/help/toolbox/stats/ksdensity.html
I know there is ecdf, but I'm not sure it's based on kernel density
smoothing. Thanks
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2003 Jun 17
2
kernel smoothing for ordinal data
Hi there,
during my work I have to use kernel smoothing methods for multivariate
ordinal data.
The R-package "KernSmooth" unfortunately includes only a version for
continous scaled variables.
Does anybody know whether there exists also a version for ordinal data?
Thanks for help!
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2006 Apr 06
4
weighted kernel density estimate
Dear R-users,
I intend to do a spatial analysis on the genetic structuring within a
population. For this I had thought to prepare a kernel density estimate
map showing the spatial distribution of individuals, while incorporating
the genetic distances among individuals. I have a dataset of locations
of N unique individuals (XY-coordinates) and an NxN matrix with the
genetic distances given as a
2009 Nov 05
5
Density estimate with bounds
Dear R users,
I would like to show the estimated density of a (0, 1) uniformly distributed
random variable. The density curve, however, goes beyond 0 and 1 because of the
kernel smoothing.
Example:
x = runif(10000)
plot(density(x))
Is there a way to estimate the density curve strictly within (0, 1) and still
use some sort of smoothing?
Any help would be greatly appreciated.
Best regards,
2010 Sep 03
2
density() with confidence intervals
Hello R users & R friends,
I just want to ask you if density() can produce a confidence interval, indicating how "certain" the density() line follows the true frequency distribution based on the sample you feed into density().
I've heard of loess.predict(loess(y ~ x), se=TRUE) which gives you a SE estimate of the smoothed scatterplot - but density() kernel smoothing is not the
2009 Aug 22
1
plotting the graph of density with an unknown distribution
How can I plot the graph of a density of a sample with an unknown distribution? I can provide any sample size which is required. I want to have a smooth density graph of my data.
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2012 Jul 19
1
3-d kernel smooth by the "kde" function
Dear R community,
I'm having hard time to understand the kde function in "ks" package. Let me
use a 3-dimensional kernel smooth example to explain my question using the
elevation data in geoR.
### here is what I did ###
library(ks)
require(geoR)
data(elevation)
elev.df <- data.frame(x = elevation$coords[,"x"], y =
elevation$coords[,"y"], z = elevation$data)
2000 Jun 20
1
density estimation in two dimensions
Hello,
I am a newbie to R and the subject of density estimation in two
dimensions or more.
I would like to have some advice concerning a comparison between the R
packages
for density estimation in bivariate or higher order problems; I mean
explicitly
the packages:
1) ash
2) KernSmooth
3) locfit
4) sm.
My specific problem now is having a set of numerical pairs (x_i, y_i),
arising from
a
2011 Dec 23
2
missing value where TRUE/FALSE needed
Merry Xmas to all,
I am writing a function and curiously this runs sometimes on one data set
and fails on another and i cannot figure out why.
Any help much appreciated.
If i run the code below with
data <- iris[ ,1:4]
The code runs fine, but if i run on a large dataset i get the following
error (showing data structures as matrix is large)
> str(cluster.data)
num [1:9985, 1:811] 0 0 0 0
2003 Jan 08
1
Lattice: Plotting two densities on the same plot(s)?
I am trying to plot two density lines on the same graph. Using the
functions on the base package, I would go:
plot(density(x), col = 1)
lines(density(y), col = 2)
And I get two distinct (one-bump) density lines. When I try to do it
using lattice, I get two two-humped lines. (In other words, I think the
smoothing function is taking the next set of data points and smoothing them
in the same
2005 Aug 16
1
kernel smoothing of weighted data
Hi,
I want to use kde() or a similar function for kernel smoothing but I want
to specify the weight of each of my data points. I do not want to specify
the bandwidth on a point by point basis.
This seems such a simple and obvious thing to want to do I am suspicious
that there is not an obvious way to do it. The only discussion I have
found is about negative weights(!) and says nothing
2010 Jun 30
3
Factor Loadings in Vegan's PCA
Hi all,
I am using the vegan package to run a prcincipal components analysis
on forest structural variables (tree density, basal area, average
height, regeneration density) in R.
However, I could not find out how to extract factor loadings
(correlations of each variable with each pca axis), as is straightforwar
in princomp.
Do anyone know how to do that?
Moreover, do anyone knows
2008 Nov 20
4
Dequantizing
I have some data measured with a coarsely-quantized clock. Let's say
the real data are
q<- sort(rexp(100,.5))
The quantized form is floor(q), so a simple quantile plot of one
against the other can be calculated using:
plot(q,type="l"); points(floor(q),col="red")
which of course shows the characteristic stair-step. I would like to
smooth the quantized
2008 Nov 25
3
plotting density for truncated distribution
I am using density() to plot a density curves. However, one of my variables
is truncated at zero, but has most of its density around zero. I would like
to know how to plot this with the density function.
The problem is that if I do this the regular way density(), values near zero
automatically get a very low value because there are no observed values
below zero. Furthermore there is some density
2001 Jan 24
3
sm.density
Hello to everyone
I''ve downloaded the version sm2 for smoothing methods and when I try the simple code
y <- rnorm(50)
sm.density(y, model = "Normal")
I get the error message
Error in if (any(omit)) { : missing value where logical needed
I''m running R 1.1.1. on windows 98
Anybody can help?
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2003 Apr 05
2
WARNING: rsync mirror is erased when remote HD-dies
Hello,
I faced a problem with rsync-ing like this
server blue 3-HD's as Linux Sofware-RAID 0 (striping) - Webserver EXT3
server green 3-HD's as Linux Sofware-RAID 0 (striping) - Backupserver EXT3
During the rsync-2.4.6-13 process one of the HD's on blue died. Though
rsync decided to remove the mirrored directories from green (the
backup-server).
This process resulted in a partial
2007 Feb 06
2
Request for Developement
Dear fellows,
Thank you. Our company engaged in developing Voice conference sofware.Now we are using speex 1.0.5 acm for our sofware.And we are using VB6 for our develpement. We would like to know anybody is intrested in developing VC++ dll which could export encode decode of speex to vb so that we can use it VB6.Our clients would be pleased to invest money for it.
thank you
regards
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)
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Faculty of Computer Science
Computer Supported Didactics Working Group
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2003 Oct 22
1
2 D non-parametric density estimation
I have spatial data in 2 dimensions - say (x,y). The correlation
between x and y is fairly substantial. My goal is to use a
non-parametric approach to estimate the multivariate density describing
the spatial locations. Ultimately, I would like to use this estimated
density to determine the area associated with a 95% probability contour
for the data.
Given the strong correlation between x and