Displaying 20 results from an estimated 500 matches similar to: "Inquiry about bandwidth rescaling in Ksmooth"
2023 Oct 26
1
Inquiry about bandwidth rescaling in Ksmooth
Apologies in advance if my comments don't help, in which case, no need
to respond, but I noted in ?ksmooth:
"bandwidth
the bandwidth. The kernels are scaled so that their quartiles (viewed
as probability densities) are at ? 0.25*bandwidth." So, could this be
a source of the discrepancies you cited?
Given that ?ksmooth explicitly says:
"Note:
This function was implemented for
2005 Dec 02
1
NA as the output of ksmooth
Dear R user,
My input data, positive and negative, is complete without missing data. After running ksmooth( ) , I receive for $y , many NAs. What could be the reasons and how can I receive complete output?
So many thanks for any help.
Amir Safari
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2005 Dec 07
2
Bandwidth selection for ksmooth( )
Dear R Users,
Before running ksmooth( ), a suitable bandwidth selection is needed. I use some functions for this task and receive these results for my data:
width.SJ(y,nb=100,method="ste") : 40.25
bcv(y,nb=100) : 40.53
ucv(y) : 41.26
bandwidth.nrd(y) : 45.43
After implementing the function ksmooth(x,y, bandwidth= each of abovementioned bandwidths), I have some NAs
2003 Sep 22
2
ksmooth in SPLUS vs R
I am working with a model that I have to estimate a nonparametric
function. The model is partial linear i.e.
Y=X$\beta$ + f(z) + $\epsilon$
I am using the ' double residual methods' Robinson (1988) Speckman (1988)
where I estimate a nonparametric function for each of the parametric
variables in terms of the nonparametric one i.e.
X[,i]=g(Z)+ u
this is done because I need the $E(
2010 Feb 09
1
Superimpose ksmooth() onto barplot
I'd like to superimpose a ksmooth() onto a barplot().
My data is:
> d
2009-06-20 2009-06-21 2009-06-22 2009-06-23 2009-06-24
2009-06-25 2009-06-26 2009-06-27 2009-06-28 2009-06-29 2009-06-30
2009-07-01 2009-07-02
Same Breed (B) 12.64 21.08 13.52 12.51
13.71 9.91 14.24 7.18 11.81 5.92
12.04 17.96
2006 Feb 07
2
Prediction method for lowess,loess,lokerns,lpepa,ksmooth
Hi Every Body,
I don't know why some regression functions have no related prediction function. For example lowess, loess, lokerns, lpridge, lpepa, and ksmooth.
What could help? Is there any global or wrapper function so that can help?
Regards,
Amir Safari
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2013 May 23
1
FW: Kernel smoothing with bandwidth which varies with x
Hello all,
I would like to use the Nadaraya-Watson estimator assuming a Gaussian
kernel: So far I sued the
library(sm)
library(sm)
x<-runif(5000)
y<-rnorm(5000)
plot(x,y,col='black')
h1<-h.select(x,y,method='aicc')
lines(ksmooth(x,y,bandwidth=h1))
which works fine. What if my data were clustered requiring a bandwidth that
varies with x? How can I do that?
Thanks in
2000 Jan 24
2
help in fortran code
I would like to get the fortran code for the functions locpol and dpill
in the kernsmooth library , the purpose is to incorporate other
selection criterion for the bandwidth in which a varying bandwidths are
replaced instead of the constant bandwidth. I will send you back the
improved version as soon as I get the fortran code for the upper mention
functions. ((LOCPOLY and DPILL )))
2003 Jul 24
1
scatterplot smoothing using gam
All:
I am trying to use gam in a scatterplot smoothing problem.
The data being smoothed have greater 1000 observation and have
multiple "humps". I can smooth the data fine using a function
something like:
out <- ksmooth(x,y,"normal",bandwidth=0.25)
plot(x,out$y,type="l")
The problem is when I try to fit the same data using gam
out <-
2007 May 29
0
Using ksmooth to produce the resulting plots
Hi,
Consider the Nottingham temperature and the Sunspot data:
>data(nottem)
>data(sunspot)
Assume that we may model each data set by a nonparametic autoregressice
model of the form
Yt = m(Yt-1) +et,
What are the value of x and y for using function
ksmooth(x,y,"normal",bandwidth=0.01)?
Thanks a lot!
Owen
2008 Sep 19
3
How to do knn regression?
Hello,
I want to do regression or missing value imputation by knn. I searched
r-help mailing list. This question was asked in 2005. ksmooth and loess
were recommended. But my case is different. I have many predictors (p>20)
and I really want try knn with a given k. ksmooth and loess use band width to define
neighborhood size. This contrasts to knn's variable band width via fixing
a
2004 Oct 20
2
Plotting a 3D surface
Hi
Does R have a function or has someone written a function to draw a 3d
surface from a scatter plot of values using either ksmooth or locpoly. OR a
transform function a that merges x relation z and y relation z to (x,y)
relation z?
I tried out scatterplot3d but it seems it would take a bit of work to get
scatterplot3d to draw a curved surface.
Lawrence
1999 Jan 12
1
Installing R on alpha-dec OSF 4.0
Hi
has anyone succeeded in installing R on DEC alpha OSF 4.0 with gcc/g77
?
The PLATFORMS file mentions successful installtion on OSF 3.2 using cc.
Here is the output I get when trying to compile:
ld -shared -o eda.so line.o smooth.o
ld:
Warning: Unresolved:
floor
ceil
rsort
__exc_add_pc_range_table
__exc_add_gp_range
__exc_remove_pc_range_table
__exc_remove_gp_range
make[4]: Leaving
2009 Sep 12
2
Triangular distribution for kernel regression
Hello,
I am trying to get fitted/estimated values using kernel regression and a
triangular kernel. I have found packages that easily fit values from a
kernel regression (e.g. ksmooth) but do not have a triangular distribution
option, and density estimators that have triangular distribution options
that I can't seem to use to produce estimated values (e.g. density). Any
help is appreciated.
2005 Nov 28
2
Robust fitting
Good evening,I am Marta Colombo, student of "Politecnico di Milano". I'm studying Local Regression Techniques such as loess, smoothing splines and kernel smoothers. Choosing "symmetric" for the argument "family" in loess function it is possible to produce a robust estimate , in function smooth.spline and ksmooth I didn't find this possibility. Well, is there a
2012 Jan 11
2
2D filter in R?
Hi all,
I am looking for a command for doing 2D filtering (rectangular or
Gaussian) in R...
I have looked at ksmooth, filter and convolve but they seem to be 1D...
Any thoughts?
Thanks a lot!
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2005 Jan 17
5
find source code
I am using R 2.0.2 on a WinXP
I am trying to get the code of the Kruskal-Wallis test but
> kruskal.test
function (x, ...)
UseMethod("kruskal.test")
<environment: namespace:stats>
> ls(3)
[1] "acf" "acf2AR" "add.scope"
..............
[181] "kruskal.test" "ks.test"
2005 Sep 28
1
confidence variability bands for kernel estimators
I'm using nonparametric regression (packeges ksmooth and ks). My question:
is there any way to compute confidence bands (or variability bands) with R.
Confidence bands for functions are intervals [CLO(x);CUP(x)] such that with
probability 1-alpha the true curve is covered by the band [CLO(x);CUP(x)].
Thanks very much for any help you can offer.
Michael G??lger
2010 Apr 25
1
function pointer question
Hello,
I have the following function that receives a "function pointer" formal parameter name "fnc":
loocv <- function(data, fnc) {
n <- length(data.x)
score <- 0
for (i in 1:n) {
x_i <- data.x[-i]
y_i <- data.y[-i]
yhat <- fnc(x=x_i,y=y_i)
score <- score + (y_i - yhat)^2
}
score <- score/n
1999 Jun 12
1
R does not compile if make is not gmake
Hi,
if make and gmake are different on any machine (for example Solaris with
gnu make as gmake), then compiling fails with gmake.
A small transcript follows. If i make a link from gmake to make as under
linux, then it works.
This problem exists in all versions of R.
g77 -O2 -fPIC -c sslvrg.f -o sslvrg.o
g77 -O2 -fPIC -c stxwx.f -o stxwx.o
../../../../bin/R SHLIB -o modreg.so bsplvd.o bvalue.o