Displaying 20 results from an estimated 20000 matches similar to: "(no subject)"
2002 Jun 03
1
LTS
Hello
I want to ask if the estimator method LTS (Least Trimmed Squares) is
implemented in R. I've found the lqs(y~x,method = c("lts")) tool that
implements LTS but minimazing the sum of the `quantile' smallest squared
residuals. I don't know if this is the same as the clasical LTS, if it is,
where do I set the trim (h value to trim the LS sum)?
I'll be waiting
2012 Oct 27
0
[gam] [mgcv] Question in integrating a eiker-white "sandwich" VCV estimator into GAM
Dear List,
I'm just teaching myself semi-parametric techniques. Apologies in
advance for the long post.
I've got observational data and a longitudinal, semi-parametric model
that I want to fit in GAM (or potentially something equivalent), and I'm
not sure how to do it. I'm posting this to ask whether it is possible
to do what I want to do using "canned" commands
2010 Jun 07
1
classification algorithms with distance matrix
Dear all,
I have a problem when using some classification functions (Kmeans, PAM,
FANNY...) with a distance matrix, and i would to understand how it
proceeds for the positioning of centroids after one execution step.
In fact, in the classical formulation of the algorithm, after each step,
to re-position the center, it calculates the distance between any
elements of the old cluster and its
2008 Nov 08
2
question about the "Y of R" article in the latest R news
I found the article the "Y of R" in the latest R news to be very
interesting. It is certainly challenging me to learn more about how R works
"under the hood" as the author states. What is less clear to me is whether
this approach is primarily for teaching purposes or has a real world
application. What is meant by "fragility of reliance on the function
name defined as a
2007 Sep 06
1
The variables combined in a table from other table and combination questions
Dear All:
I need to have some data frame objects.
First aa object:
pH Formulation time Subject
[1]1.2 F 0 1
[2]7.4 S 1 2
[3] MF 2 3
[4] 3 4
[5] n i
Then, I need to produce 2*3(pH*formulation) different
tables. This table includes column of (pH,
Formulation, time S1 S2 S3 ?K..Si) and S1=
2011 Apr 04
0
AIC for robust regression
I am interested in comparing the fit of robust (i.e., S and MM) and
non-robust (i.e., OLS) estimators when applied to a particular data set.
The paper entitled "A comparison of robust versions of the AIC based on M, S
and MM-estimators" (available at:
http://ideas.repec.org/p/ner/leuven/urnhdl123456789-274771.html) presents
formulas for robust Akaike information criteria (AIC) for the M,
2004 Nov 11
3
(no subject)
Hi,
I have a list of numbers. For each of the numbers, I take sum of squares of
the numbers centered on the number chosen. If it is less than a certain
constant, I will take the average of the numbers chosen.
Anyone can give me a sample code. You help will be greatly appreciated.
Peter
[[alternative HTML version deleted]]
2012 Apr 09
0
Error using PGMM function in the PLM package
Good day fellow R users:
I have routinely received the following message when attempting to
estimate a GMM model for a somewhat square panel (N = 20, T = 9-27,
Obs = 338) using the pgmm function in the plm package:
Error in function (..., deparse.level = 1) :
number of rows of matrices must match (see arg 2)
So far, I am not wedded to a particular GMM model but what I have used
thus far is
2007 Dec 28
3
How to catch data from the different dataframes and lm problem?
Dear all:
I am a new R-user and I have 2 questions
about it.
1) I have a dataframe. Based on ?formulation? and ?subject?, a
dataframe is split into 4 dataframes. The
example is as follows. Moreover, I want
to calculate ?test? value for these 4 dataframes. My question is that the ?test? values not
correct and I do not know where the problem is.
2) There are 12 ?test? (y) values from
2018 Apr 07
0
Fast tau-estimator line does not appear on the plot
You need to pay attention to the documentation more closely. If you don't
know what something means, that is usually a signal that you need to study
more... in this case about the difference between an input variable and a
design (model) matrix. This is a concept from the standard linear algebra
formulation for regression equations. (Note that I have never used RobPer,
nor do I regularly
2009 Aug 25
1
Fw: Re: Simulating data for sampling (stupid question)
Dear All
I know that you do not have to help me (as this is not a pure R problem) but please do, i am new to R as a CPI compiler, i just need to do a sample to see which sampling method best works in different situations, therefore since this is for practice purposes nobody will finance a real project thats why i need you to help me direct me as to how simulate data (just direct me,not 100%
2009 Aug 25
0
Fw: Re: Simulating data (stupid question)
Dear All
I know that you do not have to help me (as this is not a pure R problem) but please do, i am new to R as a CPI compiler, i just need to do a sample to see which sampling method best works in different situations, therefore since this is for practice purposes nobody will finance a real project thats why i need you to help me direct me as to how simulate data (just direct me,not 100%
2007 Feb 13
1
Hierarchical ANOVA
Hello,
Does somebody could help me in the computation(formulation) of a
hierarchical ANOVA using linear model in R?
I'm working in a population biology study of an endangered species. My aim
is to see if I have effects of "Density of individuals/m2" on several
measured plants fitness traits.
As independent variables I have:
Humidity (continuous)
Nutritive substance (continuous)
2006 Oct 04
2
Linear model with hidden variables
I have some data on a moving vehicle where, amongst other things,
it looks as though it would be informative to fit a model with the
following structure:
Z = B.Y + errorz
Y = C.X + errorz
The X variables are observed predictor variables;
6 of the variables look promising (on the basis of what they mean).
The Z variables are observed response variables;
there are 4 of them.
There is a
2005 Sep 18
1
trimmed mean in R seems to round the trimming fraction
subject: trimmed mean in R seems to round the trimming fraction
to r-help at stat.math.ethz.ch.
Consider the following example of 10 numbers. 10% trimmed mean is correct
but you can see that the result is the same for many trimming fractions
till 0.20!
For example 13% trimmed mean should use interpolation of second and
eighth ordered observation. R does not seem to do this.
The correct 13%
2006 May 19
2
lmer, p-values and all that
Users are often surprised and alarmed that the summary of a linear
mixed model fit by lmer provides estimates of the fixed-effects
parameters, standard errors for these parameters and a t-ratio but no
p-values. Similarly the output from anova applied to a single lmer
model provides the sequential sums of squares for the terms in the
fixed-effects specification and the corresponding numerator
2003 Sep 04
3
Overlaying graphs
----- Original Message -----
From: "Richard A. O'Keefe" <ok at cs.otago.ac.nz>
To: <paul at datavore.com>
Sent: Thursday, September 04, 2003 2:56 AM
Subject: Re: [R] Overlaying graphs
> I do not know how to overlay the curve graphic on top of hist graphic.
>
> Do you know about the "add=TRUE" option for plot()?
>
> I am hoping to show visually
2010 Jun 11
2
Skeleton 4.0 final draft
On 06/10/2010 08:16 PM, Chris Pearce wrote:
> I have no plans to change the 'index' packet format further.
I have proposed an alternative formulation of the index packet at
http://github.com/bemasc/OggIndex/blob/master/Proposed-modified-spec.txt
That repository also contains a working implementation of the alternative
formulation. I have reviewed the details with Chris extensively.
2010 Jun 11
0
Skeleton 4.0 final draft
On 11/06/2010 1:06 p.m., Benjamin M. Schwartz wrote:
> On 06/10/2010 08:16 PM, Chris Pearce wrote:
>> I have no plans to change the 'index' packet format further.
> I have proposed an alternative formulation of the index packet at
>
> http://github.com/bemasc/OggIndex/blob/master/Proposed-modified-spec.txt
>
> That repository also contains a working implementation
2004 Dec 12
2
Re: [R] Is k equivalent to k:k ?
I asked:
> In this discussion of seq(), can anyone explain to
> me _why_ seq(to=n) and seq(length=3) have different
> types?
Martin Maechler <maechler@stat.math.ethz.ch> replied:
well, the explantion isn't hard: look at seq.default :-)
That's the "efficient cause", I was after the "final cause".
That is, I wasn't asking "what is it