Displaying 20 results from an estimated 100 matches similar to: "Quelplot"
2003 Jun 16
3
Constrained optimization
Greetings, R-Wizards:
I'm trying to find an extremum subject to a nonlinear constraint. (Yes, I
have perused the archives but have found nothing positive.) The details of
the problem are these:
In a paper published some years ago in Technometrics, ("Confidence bands for
cumulative distribution functions of continuous random variables"
Technometrics, 25, 77-86. 1983), Cheng and
2005 Oct 28
2
Uncensoring a dataset - resent
Does anyone know of an R package that I can use to uncensor a normal or
log-normal dataset? I'm particularly interested in the MLE method of
Cohen (1959), "Simplified estimators for the normal distribution when
samples are single censored or truncated," Technometrics, 1(3), 217-237.
Of course, if there is anything better, I'd be glad to hear about that
too.
Thanks.
Rick
2006 Mar 28
2
Welch test for equality of variance
Hello
Using R 2.2.1 on a Windows machine.
Has anyone programmed the Welch test for equality of variances?
I tried RSiteSearch, but this gave references to t test and
oneway.test, which are not quite what I need.....I need the Welch test
itself, for use in a meta-analysis (to determine if variances are
equal).
TIA
Peter
Peter L. Flom, PhD
Assistant Director, Statistics and Data Analysis
2003 Apr 03
1
Tukey's one degree of freedom for nonadditivity?
Is there code available to decompose interactions involving at least
one nominal factor with more than 2 levels as described, e.g., by Tukey
or by Mandel (1971, Technometrics, 13: 1-18)?
Tukey's model:
E(y[i,j]) = mu0 + a[i] + b[j] + c*a[i]*b[j],
estimating a, b, and c so sum(a) = sum(b)= 0. Mandel essentially
describes a singular value decomposition of the interaction.
Thanks,
2003 Sep 11
1
S+DOX eqivalent in R?
Dear List,
I am looking for a function `Pseudo standard error' (PSE), which is
available in S+ DOX (design of experiemnt) module - Is there a similar
function available in R?
Reference for PSE function is in the paper:
'Quick and easy analysis of unreplicated factorials' by Russell V. Lenth,
Technometrics, 1989, 31, 4, 469-473.
Thanks.
-Nitin
2005 Dec 02
1
Zero-inflated neg.bin. model and pscl package
Dear list,
I'm currently trying to develop a model to assess clam yield potential in a
lagoon. I'm using the zeroinfl function of the pscl package to fit a
Zero-inflated negative binomial model, given the high occurrence of zero
counts.
I don't understand from the sentence in the pscl guide "Zero-inflated count
models are a type of two-component mixture model, with a component
2005 Apr 22
2
Hoaglin Outlier Method
I am a new user of R so please bear with me. I have reviewed some R books,
FAQs and such but the volume of material is great. I am in the process of
porting my current SAS and SVS Script code to Lotus Approach, R and
WordPerfect.
My question is, can you help me determine the best R method to implement
the Hoaglin Outlier Method? It is used in the Appendix A and B of the fo
llowing link.
2012 Apr 26
2
Lambert (1992) simulation
Hi,
I am trying to replicate Lambert (1992)'s simulation with zero-inflated
Poisson models. The citation is here:
@article{lambert1992zero,
Author = {Lambert, D.},
Journal = {Technometrics},
Pages = {1--14},
Publisher = {JSTOR},
Title = {Zero-inflated {P}oisson regression, with an application to defects
in manufacturing},
Year = {1992}}
Specifically I am trying to recreate Table 2. But my
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!
--
2003 Mar 12
1
problems with numerical optimisation
Dear list,
this is not a particular R question but perhaps someone can help.
I am running a maximum likelihood estimation (competing risk duration
model with unobserved heterogeneity) on 30 different datasets. The
problem is that on 2 datasets the model does not converge. I am
interested if there are any methods, based on the gradients or (an
approximation of) the hessian which helps to
2003 Jun 27
1
A vector or matrix response
Hello,
I wonder if anybody has some idea about how to solve my problem :
I am working , I would say trough an experimental design approach (perform
experiments, get responses, make regression, sensitivity analysis, risk
analysis ...). The problem is now that I have to face with not only a
response but a vector or a matrix (typically a spatial distribution of a
physical property ... pressure).
2004 Jan 20
2
question
Je suis étudiant en DEA et j'élabore un mémoir dans lequel j'applique le modèle STARMA ,
Pouvez vous ,s'il vous plait, m'envoyer l'algorithme de calcul ces STACF et STPACF de ce model afin de débuter mon estimation de ce modéle sur R
Merci d'avance.
---------------------------------
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2009 Nov 16
1
lmomco package and confidence limits?
Hello,
I am using the lmomco package (lmom.ub and pargev) to compute the GEV
parameters (location, scale, and shape), which are used to estimate
return values. I was wondering how/if I can calculate upper and lower
confidence (CI_u, CI_l) intervals for each return frequency using the
GEV parameters to fill-in the table below?
Xi (location) = 35.396
Alpha (scale) = 1.726
Kappa (shape) =
2007 Feb 12
6
Boxplot: quartiles/outliers
For boxplot(), is it possible to pass in a parameter to change the default
way that the 1st and 3rd quartiles are computed? (specifically, I'd like to
use type 6 described in the quantile function).
Also, what are the options for how outliers are computed, and how can one
change them?
Thank you
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2002 May 14
1
princomp
Hello experts,
as newcomer in pca, i have a question, concerning the princomp algorithm.
With a dataset "r" containing 18 "input" parameters and 1 "output" parameter
r[19], i got with the following fit
ls <- lsfit(r[1:18],r[19]); lsdiag <- ls.diag(ls); lsdiag$std.dev
a prediction error of:
[1] 8.879561
what is quite reasonable. If i take only two
2003 Feb 20
3
outliers/interval data extraction
Dear R-users,
I have two outliers related questions.
I.
I have a vector consisting of 69 values.
mean = 0.00086
SD = 0.02152
The shape of EDA graphics (boxplots, density plots) is heavily distorted
due to outliers. How to define the interval for outliers exception? Is
<2SD - mean + 2SD> interval a correct approach?
Or should I define 95% (or 99%) limit of agreement for data interval,
2003 Nov 13
3
conf int mixed effects
Hi,
I have a linear mixed-effects model object and want to extract the 95%
confidence intervals for the fixed and random effects, respectively. I
found the function intervals() for confidence intervals for the fixed
effects but no corresponding function for the random effects. Does it
exist or do I have to calculate the confidence intervals for the random
effects myself?
Greetings,
joerg
2006 Apr 13
2
Plotting positions in qqnorm?
Do you know of a reference that discusses alternative choices for
plotting positions for a normal probability plot? The documentation for
qqnorm says it calls ppoints, which returns qnorm((1:m-a)/(m+1-2*a))
with "a" = ifelse(n<=10, 3/8, 1/2)? The help pages for qqnorm and
ppoints just refer to Becker, Chambers and Wilks (1988) The New S
Language (Wadsworth & Brooks/Cole),
2004 Oct 21
5
Cluster Analysis: Density-Based Method
Hi people,
Does anybody know some Density-Based Method for clustering implemented in R?
Thanks,
Fernando Prass
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2000 Jul 28
2
Using the nls package
I'm a bit confused about the nls package, I'm trying to use it for curve fitting.
First off, the documentation for nls says ``see `nlsControl' for the
names of the settable control values'' -- this is wrong, it should be
nls.control (minor point but had me confused for a moment).
Now I'll try something very simple (maybe too simple):