Displaying 20 results from an estimated 10000 matches similar to: "quasi-random vector according to an independent graph"
2005 Sep 22
4
how to keep very small or large number?
When I was computing some joint probabilities, I found
that R reported most of the results to to -Inf and
thus didn't record the value. I guess it is b/c the
joint log(probability) can be extremely small. Is
there a way in R to keep the values even if they are
small?
2005 Sep 29
1
plot.augPred sorted and labelled according second factor
Hi
using this code example:
library(nlme)
fm1 <- lme(Orthodont, random = ~1)
plot(augPred(fm1))
is there any way to have the plots in each cell labelled and ordered
according to Orthodont$Sex? I.e. in addition to the bar with the label for
Orthodont$Subject there is another bar labelling the Sex of the subject?
thanks a lot
christoph
--
2005 Jun 23
2
solving equation system
Hello,
I want to solve some two dimensional equation system with R. Some systems
are not solvable analytically.
Here is an example:
(I) 1/n*sum{from_i=1_to_n}(Xi) = ln lambda + digamma(c)
(II) mean(X) = x / lambda
I want to find lambda and c,
which R-function could do that task?
Carsten
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2005 Aug 12
3
General expression of a unitary matrix
Hi, all,
Does anybody got the most general expression of a unitary matrix?
I found one in the book, four entries of the matrix are:
(cos\theta) exp(j\alpha); -(sin\theta)exp(j(\alpha-\Omega));
(sin\theta)exp(j(\beta+\Omega)); (cos\theta) exp(j\beta);
where "j" is for complex.
However, since for any two unitary matrices, their product should also
be a unitary matrix. When I
2005 Aug 17
2
power of a matrix
Dear all,
I have a population with three age-classes, at time t=0 the population
is:
n.zero <- c(1,0,0)
I have a transition matrix A which denotes "fertility" and "survival":
A <- matrix(c(0,1,5, 0.3,0,0, 0,0.5,0), ncol=3, byrow=TRUE)
To obtain the population at t=1, I calculate:
A %*% n.zero
To obtain the population t=2, I calculate:
A %*% (A %*% n.zero)
... and so
2005 Jun 28
2
the function of mle
Hi,
I am a user of R computer language.Several days ago,I download R-2.1.0.From
the help manual,I saw there is a function "mle" to find the maximum
likelihood estimators.But when I try to use this function,there is no this
function.Could you help me to solve this problem?
I am looking forward to your answer.
Thank you.
Jun Liu
2005 Oct 07
3
panel data unit root tests
Hi,
The question is as follows: has anyone coded panel data unit root tests
with R? Even the "first generation" tests (see e.g. Levin & Lin 1993;
Pesaran, & Smith & Im 1996; Maddala & Wu 1999) would be sufficient for my
needs. To my understanding, these are rather easy to code, but as I have
taken just my first steps in coding with R, existing code would save me
2005 Dec 16
3
partially linear models
Hey,
I am estiamting a partially linear model y=X\beta+f(\theta) where the f(\theta) is estiamted using wavelets.
Has anyone heard of methods to test if the betas are significant or to address model fit?
Thanks for any thoughts or comments.
Elizabeth Lawson
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2005 Sep 12
1
Glmm for multiple outcomes
Dear All,
I wonder if there is an efficient way to fit the generalized linear mixed model for multivariate outcomes.
More specifically, Suppose that for a given subject i and at a given time j we observe a multivariate outcome Yij = (Y_ij1, Y_ij2, ..., Y_ijK).
where Y_ijk is a binomial(n_ijk, p_ijk).
One way to jointly model the data is to use the following specification:
g(p_ijk) =
2005 Jul 14
2
Variance components from lm?
I often use simple nested random-effect models for interlaboratory data.
The variance components are important things to know.
Is there an R function or package that gets variance components from lm
objects? Or can someone point me to a method of doing so?
2005 Jul 06
2
Plotting confidence intervals for lme
Hello and sorry to disturb.
I'm trying to plot the confidence intervals for the fixed effects of a lme.
I want to obtain graphically, if it is possible, a bar with Estimate, upper
and lower CI for each level of the factors.
I know how to do for a lm model but for a lme one, I tried with
plot(intervals(...)) and plot(ci(...)) from the gmodels package but it
doesn't work well.
Thanks
2005 Nov 03
4
nlme questions
Dear R users;
Ive got two questions concerning nlme library 3.1-65 (running on R 2.2.0 /
Win XP Pro). The first one is related to augPred function. Ive been working
with a nonlinear mixed model with no problems so far. However, when the
parameters of the model are specified in terms of some other covariates,
say treatment (i.e. phi1~trt1+trt2, etc) the augPred function give me the
following
2005 Dec 27
3
parameterization of factor in R
Hi all,
I encountered this problem with parameterization in R:
I have two factors in a regression. how about if I want to
set constraint so that for each factor, the sum of their
coefficients equals to zero(instead of choosing a reference
category)? for example, I have factor(variable) A(with three
categories) and factor(variable) B(with 4 categories), and I want
to parameterize so that the sum
2005 Oct 31
2
nlme error message
Dear Friends,
I am seeking for any help on an error message in lme
functions. I use mixed model to analyze a data with
compound symmetric correlation structure. But I get an
error message: "Error in corMatrix.corCompSymm(object) :
NA/NaN/Inf in foreign function call (arg 1)". If I change
the correlation structure to corAR1, then no error. I have
no clue how to solve this problem.
2005 Oct 03
2
"symbol print-name too long"
All,
I've coded a function and it works manually if I copy it line by line into R.
However, when I try to "load" (copy and paste) the entire function into
R, I get the following error after the listed line of code:
+ N.j.list = lapply(rej.hyp, length)
Error: symbol print-name too long
Does anyone you know what this error means? Strangely, when I copy the
same line verbatim
2005 Dec 22
2
Testing a linear hypothesis after maximum likelihood
I'd like to be able to test linear hypotheses after setting up and running a
model using optim or perhaps nlm. One hypothesis I need to test are that
the average of several coefficients is less than zero, so I don't believe I
can use the likelihood ratio test.
I can't seem to find a provision anywhere for testing linear combinations of
coefficients after max. likelihood.
Cheers
2005 Oct 04
2
Need help on ARIMA (time series analysis)
Hi,
I am so novice in using R. I have some problems in my R script below
which fits time series data and predict it one-step ahead. Here is a
brief explanation on what I try to achieve
Th16k is time series data (500 data points). The size of window for
fitting and predicting is 50 (data points). As you can easily discover
from my code, (fixed) window is moving/sliding to get next one-step
2005 Sep 19
4
factor as seq() in for loop
Dear all,
I would like to use the values in vegaggr.BLMCMR02$colony
str(vegaggr.BLMCMR02)
`data.frame': 1678 obs. of 3 variables:
$ vegtype : Factor w/ 27 levels "2010","2020",..: 3 4 5 19 4 5 19 5
$ colony : Factor w/ 406 levels "0","1","10","100",..: 1 1 1 1 2 2 2
$ Totvegproparea: num 0.00055 0.03956 0.95705
2018 Mar 07
2
Call for Papers: ManLang 2018 (Sept. 10-14, Linz, Austria)
------------------------------------------------------------------------------------------------
CALL FOR PAPERS
15th International Conference on Managed Languages & Runtimes
(ManLang'18)
September 10-14, 2018, Linz, Austria
http://ssw.jku.at/manlang18/
------------------------------------------------------------------------------------------------
ManLang (formerly PPPJ) is a
2005 Dec 04
1
Understanding nonlinear optimization and Rosenbrock's banana valley function?
GENERAL REFERENCE ON NONLINEAR OPTIMIZATION?
What are your favorite references on nonlinear optimization? I like
Bates and Watts (1988) Nonlinear Regression Analysis and Its
Applications (Wiley), especially for its key insights regarding
parameter effects vs. intrinsic curvature. Before I spent time and
money on several of the refences cited on the help pages for "optim",