Displaying 20 results from an estimated 3000 matches similar to: "Cross-correlated variables in kernel density estimation"
2008 Jan 16
1
Probability weights with density estimation
I am a physician examining an NHANES dataset available at the NCHS
website:
http://www.cdc.gov/nchs/about/major/nhanes/nhanes2005-2006/demo_d.xpt
http://www.cdc.gov/nchs/about/major/nhanes/nhanes2005-2006/hdl_d.xpt
http://www.cdc.gov/nchs/about/major/nhanes/nhanes2005-2006/tchol_d.xpt
Thank you to the R authors and the foreign package authors in
particular. Importing from the SAS export
2011 Nov 24
2
Question on density values obtained from kde2d() from package MASS
Hello,
I am a little bit confused regarding the density values obtained from the function kde2d() from the package MASS because the are not in the intervall [0,1] as I would expect them to be. Here is an example:
x <- c(0.0036,0.0088,0.0042,0.0022,-0.0013,0.0007,0.0028,-0.0028,0.0019,0.0026,-0.0029,-0.0081,-0.0024,0.0090,0.0088,0.0038,0.0022,0.0068,0.0089,-0.0015,-0.0062,0.0066)
y <-
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
2010 Feb 15
4
density estimates for fixed points
Problem:
Based on a n x 2 data matrix i want a kernel estimate of the bivariate
density. However, i also wish to specify wich points the density should be
calculated at.
I can offcourse just write the full kernel density estimate as a R-code, but
surely there must already exist some package for this operation?
The package density(), seems to create a new matrix (depending on n), where
the
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
2007 Nov 26
2
2d Joint Density Plot
Hi all,
I'm fairly new to R, so I'm still trying to feel out what is available to
me. I would like to be able to plot joint density in a two dimensional plot
where density is indicated by color or darkness gradients, like a 2d color
coded topographic map. Ideally, the output would be something I could then
plot other points or lines on.
Currently, I'm calculating joint density with
2009 Dec 02
2
Joint density kde2d works improperly?
Dear all,
Please, look at the following code:
attach(geyser)
f1 <- kde2d(duration, waiting, n = 5)
a <- 0
for (i in 1:5){
for (j in 1:5){
a <- a + f1$z[i,j]
}
}
As far as I understood from Help kde2d returns matrix elements of which are
values of joint probability mass function Pr(X=x,Y=y) therefore, sum of its
elements should sum to 1.
Which is not the case from my check.
Where is
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
2012 Jul 05
3
[LLVMdev] "symbol lookup error" while running a Simple Loop Pass
Hello;
I wrote this simple loop pass to collect the number of instructions in each
loop of the program. The code is as follows-
#define DEBUG_TYPE "loopinst"
#include "llvm/Pass.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Instructions.h"
#include
2002 Dec 09
1
3D density estimation
I am trying to carry out density estimation for three dimensions
(with anywhere between a few hundred and ~8000 data points). Which
leads me to ask:
a) is there any equivalent to kde2d (in MASS) or bkde2D (in
KernSmooth) out there for three dimensions?
b) if not, my skills only seem to extend as far as writing a function
which measures density as the number of data points falling within a
2012 Jul 05
1
[LLVMdev] "symbol lookup error" while running a Simple Loop Pass
Hi,
> Problem solved. I was building llvm in a separate llvm-build directory. I
> built it within the llvm-src directory (which kept all the llvm .so and my
> pass' .so in the llvm-src/Release+Asserts/lib directory) to solve the
> problem.
I do not fully understand what you mean, there should be no difference
on building out of source AFAIK.
> Can anyone tell me what's
2012 Jul 05
0
[LLVMdev] "symbol lookup error" while running a Simple Loop Pass
Problem solved. I was building llvm in a separate llvm-build directory. I
built it within the llvm-src directory (which kept all the llvm .so and my
pass' .so in the llvm-src/Release+Asserts/lib directory) to solve the
problem.
Can anyone tell me what's the difference between writing a pass as a
"struct" (as in the tutorial) and as a "class" (as most developers do)?
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
2010 Nov 20
2
How to do a probability density based filtering in 2D?
Hello,
This sounds like a problem to which many solutions should exist, but I
did not manage to find one.
Basically, given a list of datapoints, I'd like to keep those within
the X% percentile highest density.
That would be equivalent to retain only points within a given line of
a contour plot.
Thanks to anybody who could let me know which function I could use!
Best,
Emmanuel
2009 Mar 17
1
help with 3-D plot of kernel density estimates
Hi,
I guess I have a naive question. I use kde2d function in a standard way to
estimate kernel densities of x and y (x and y are vectors) and plot them
using image().
f1=kde2d(x,y)
image(f1)
But what if I want to see kernel estimates of three variables, x, y and z (a
vector) plotted together ? Something in which x<->y is plotted and colored
according to the corresponding value of z ?
2010 Apr 04
2
One question about saving graph by using xyplot
Hey, folk.
I am trying to get many figures by using the function "xyplot" in the library "lattice". I tried to using the loop to finish it quickly. But I cannot open the saved file after I run the program. But if I use the function "plot" to get other simply figures, it can work. So I want to ask how I can get the saved figures by using "xyplot".
The
2012 May 20
1
[LLVMdev] Error While Inserting New Instruction to LLVM IR
Hello;
I wanted to insert two new terminator instructions in LLVM IR. I modified
the necessary files (as mentioned in the tutorial in LLVM site and some
more to meet the new structure of LLVM, (e.g no Lexer.l now, we have
LLLexer.cpp. Again in the tutorial, files like LLVMBitCodes.h,
include/llvm-c/core.h that need to be modified are not mentioned) But I am
getting the error while building
2013 Nov 05
2
[LLVMdev] Identifying the instructions that uses a pointer used as a function argument
Hello all;
So here is my goal:
*** If there is a Call instruction to myFunction(int * val), I need to
identify all the instructions that uses val in the IR and replace the
uses with a newly created pointer. I will also be changing the
argument of myFunction to the new pointer.
int * val = malloc/calloc;
...
myFunction(val);
....
*val = 45;
becomes==
int * val = malloc/calloc;
int * val1 =
2004 Apr 10
2
Density Estimation
Dear Sir/Madam;
Would you please tell me what is the command that allows the estimation of the Kernel Density for some data.
Thanks,
Thami Rachidi
[[alternative HTML version deleted]]
2005 Apr 22
1
density estimation
hello
sorry for my english
I would like estimate density for multivariate variable,( f(x,y) , f(x,y
,z) for example) ; for calculate mutual information
how is posible with R?
thanks
Bernard
Bernard Palagos
Unité Mixte de Recherche Cemagref - Agro.M - CIRAD
Information et Technologie pour les Agro-Procédés
Cemagref - BP 5095
34033 MONTPELLIER Cedex 1
France