[EMAIL PROTECTED]
Research Associate (Statistician)
Modeling Data Analytics
ARPC
-Original Message-
From: Prof Brian Ripley [mailto:[EMAIL PROTECTED]
Sent: Monday, January 22, 2007 11:01 PM
To: Louisell, Paul
Cc: r-help@stat.math.ethz.ch
Subject: Re: [R] Loess with more than 4 predictors
Analytics
ARPC
-Original Message-
From: Louisell, Paul
Sent: Tuesday, January 23, 2007 12:40 PM
To: 'Prof Brian Ripley'
Cc: r-help@stat.math.ethz.ch
Subject: RE: [R] Loess with more than 4 predictors / offsets
In response to your questions:
I asked about including the offset
Hello,
Does anyone know of an R version of loess that allows more than 4
predictors and/or allows the specification of offsets? For that matter,
does anyone know of _any_ version of loess that does either of the
things I mention?
Thanks,
Paul Louisell
650-833-6254
[EMAIL PROTECTED]
Research
On Mon, 22 Jan 2007, Louisell, Paul wrote:
Hello,
Does anyone know of an R version of loess that allows more than 4
predictors and/or allows the specification of offsets? For that matter,
does anyone know of _any_ version of loess that does either of the
things I mention?
Why would you
Hi,
I have tried
for (i in 1:100) L[,i] - loess((i = =(1:100))~I(1:100), span=.5,
degree=1)$fit
to create a matrix which gives me the smoothing weights (correctly as
far as I have experienced), eg.
yhat - loess(y~I(1:100), span=.5,degree=1)$fit
yhat[30]
[1] -0.2131983
L[30,]%*%y
On Thu, 4 Jan 2007, Jukka Nyblom wrote:
Hi,
I have tried
for (i in 1:100) L[,i] - loess((i = =(1:100))~I(1:100), span=.5,
degree=1)$fit
to create a matrix which gives me the smoothing weights (correctly as
far as I have experienced), eg.
yhat - loess(y~I(1:100), span=.5,degree=1)$fit
Hello:
I recall something like this being discuss recently, but I can't seem
to locate an example in the archives. I have data like the following:
df - expand.grid(1:4, 1992:2002)
names(df) - c(MSA, YEAR)
df$IDUPREV - runif(44)
df$VALIDAT - rnorm(44)
I want to create an xyplot() with
Try this:
xyplot(IDUPREV + VALIDAT~ YEAR | MSA, data = df, type= c(smooth, o))
On 11/23/06, Chuck Cleland [EMAIL PROTECTED] wrote:
Hello:
I recall something like this being discuss recently, but I can't seem
to locate an example in the archives. I have data like the following:
df -
I am trying to smooth a dataset with evenly spaced values of x,
perhaps using loess smoothing or something similar. However, the y
values are hypergeometrically distributed; I think I want to use a
logarithmic link function. It falls under the general heading of
non-parametric regression. The
:53 AM
To: R-project help
Subject: [R] loess smoothing question
I am trying to smooth a dataset with evenly spaced values of x,
perhaps using loess smoothing or something similar. However, the y
values are hypergeometrically distributed; I think I want to use a
logarithmic link function
Is there an R implementation of a scheme for automatic smoothing
parameter selection with loess, e.g., by minimizing one of the AIC/GCV
statistics discussed by Hurvich, Simonoff Tsai (1998)?
Below is a function that calculates the relevant values of AICC,
AICC1 and GCV--- I think, because I to
On Thu, 17 Nov 2005, Michael Friendly wrote:
Is there an R implementation of a scheme for automatic smoothing
parameter selection with loess, e.g., by minimizing one of the AIC/GCV
statistics discussed by Hurvich, Simonoff Tsai (1998)?
If you particularly want loess smoothing then I don't
://socserv.mcmaster.ca/jfox
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of
Michael Friendly
Sent: Thursday, November 17, 2005 9:58 AM
To: R-help@stat.math.ethz.ch
Subject: [R] loess: choose span to minimize AIC
-525-9140x23604
http://socserv.mcmaster.ca/jfox
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of
Michael Friendly
Sent: Thursday, November 17, 2005 9:58 AM
To: R-help@stat.math.ethz.ch
Subject: [R] loess: choose span
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of
Michael Friendly
Sent: Thursday, November 17, 2005 9:58 AM
To: R-help@stat.math.ethz.ch
Subject: [R] loess: choose span to minimize AIC?
Is there an R implementation
I have a problem either understanding what loess is doing or that loess
has a problem itself.
As the x-axis variables become more concentrated on a particular point,the
estimated loess tends to zero. the examples below show what i am
talking about, why is that? my intution tells me
that it
The problem is that 90% of your data sit on the boundary. Loess is a
nearest neighbor smoother (using (100 x span) % of the data to estimate at
each point). If you call loess() directly with span=2/3 (the default in
scatter.smooth), or something smaller than about 0.91, you'll see that it
has
Dear list,
I would like to know it is possible to test the significance of a loess ; in other
words, I would like to know if the loess I got is significantly different from a
linear model.
Thanks.
Aurélie Coulon.
[[alternative HTML version deleted]]
]
To: [EMAIL PROTECTED]
Sent: Thursday, October 21, 2004 8:37 AM
Subject: [R] loess significance
Dear list,
I would like to know it is possible to test the significance of a loess ; in
other words, I would like to know if the loess I got is significantly
different from a linear model.
Thanks
Hello
I am plotting a loess curve with confidence limits as below.
How do I create the prediction limits? Is multiplying the standard
errors by sqrt(n) appropriate?
data - mndata
lo - loess(data[[variableName]] ~ Age, data, span=1.0,
control = loess.control(surface = direct))
xPoints -
On Tue, 25 May 2004, Rupen Shrestha wrote:
When I was running the function loess(y~x, span=0.0020), I got a warning
message k-d tree limited by memory. ncmax= 4231
Does that mean the function has not been computed correctly ? If it has not,
is there any way to adjust it so that it will do
Hi,
When I was running the function loess(y~x, span=0.0020), I got a warning
message k-d tree limited by memory. ncmax= 4231
Does that mean the function has not been computed correctly ? If it has not,
is there any way to adjust it so that it will do correctly ?
Thanks.
Rupen.
Hi there fellow R-users,
I have just upgraded to R version 1.9.0 from R version 1.7.1 for Windows.
Im trying to use the loess smoother where the X-variable is an as.POSIXct
variable.
The following works fine with R1.7.1 but not with R1.9.0.
Here is the example:
hi!
i want to change the robustness weights used by loess. these
are described on page 316 of chambers and hastie's statistical models in S
book as
r_i = B(e_i,6m)
where B is tukey's biweight function, e_i are the residulas, and m is the
median average distance from 0 of the residuals. i
On Fri, 9 Apr 2004, Rafael A. Irizarry wrote:
hi!
i want to change the robustness weights used by loess. these
are described on page 316 of chambers and hastie's statistical models in S
book as
r_i = B(e_i,6m)
where B is tukey's biweight function, e_i are the residulas, and m is the
Hi,
I have been successfully using the loess function for normalisation of a 2D
array set.
We have recently improved the quality criteria for the data and the numbers
of data points has been reduced to around from around 1000 to 700.
Previously the following would return the loess normalised
You are probably running out of memory address space. Can you
1) Try this in 1.9.0 beta which gives a more informative error message,
and
2) Use traceback() and the debugging tools to locate the error more
exactly.
3) Consider using the options to loess to reduce the load. Loess is not
Hi,
I am using Loess.smooth (Modreg) in order to infer certain relationship
for the data set of ~130,000 observations with ~300 distinct values of
single predictor. I understand that fitted values (y-hat) are just 300
Weighted LS fits in certain neighborhood of predictors. I am bit confused
On Sun, 23 Mar 2003, Davorka Gulisija wrote:
I am using Loess.smooth (Modreg) in order to infer certain relationship
I presume you mean loess.smooth in package modreg? (People do sometimes
modify functions and (un-)capitalize the names.)
for the data set of ~130,000 observations with ~300
Dear Users,
I tried to use loess to fit a simple local quadratic: loess(y~x). But it returned the
exact y value to me. (residuals==0)
Is it too good to be true? How do I specify the SPAN in loess function?
Thanks a lot.
[[alternate HTML version deleted]]
PROTECTED]]
Sent: Thursday, February 20, 2003 10:30 AM
To: [EMAIL PROTECTED]
Subject: [R] loess
Dear Users,
I tried to use loess to fit a simple local quadratic:
loess(y~x). But it returned the exact y value to me. (residuals==0)
Is it too good to be true? How do I specify the SPAN in loess
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