Displaying 20 results from an estimated 20000 matches similar to: "How to do log normal regression?"
2005 Aug 24
1
Panel regression in R
I am currently trying to replicate the results I got
from RATS for a panel regression. The codes in RATS
looks like this:
* Final equation for Office Cap Rate Spread
* Regression, Panel Data
preg(effects=time, method=random) CapRate
# CapRate{1} RentCycle{1} VacancyChangeYTY
InflationYTY RealGDPyty
Just wonder what R package also allow me to have the
options like (effects=time, method=random).
2005 Jul 25
1
Convert quarterly data to monthly data
Hi,
I am new to use R, but can anyone tell me how to
tranform quarterly data to monthly data? I know SAS
has this procedure, so may I assume it is also
available in R?
Thanks a lot!
Ed
2005 Aug 05
1
question regarding logit regression using glm
I got the following warning messages when I did a
binomial logit regression using glm():
Warning messages:
1: Algorithm did not converge in: glm.fit(x = X, y =
Y, weights = weights, start = start, etastart =
etastart,
2: fitted probabilities numerically 0 or 1 occurred
in: glm.fit(x = X, y = Y, weights = weights, start =
start, etastart = etastart,
Can some one share your thoughts on how to
2005 Aug 02
6
can we manage memory usage to increase speed?
Hi,
Thanks for reading.
I am running a process in R for microarray data analysis. RedHat Enterprise Linux 4, dual AMD CPU, 6G memory. However, the R process use only a total of <200M memory. And the CPU usage is total to ~110% for two. The program takes at least 2 weeks to run at the current speed. Is there some way we can increase the usage of CPUs and memories and speed up? Any
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 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 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 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
2007 Jul 10
3
ECDF, distribution of Pareto, distribution of Normal
Hello all,
I would like to plot the emperical CDF, normal CDF and pareto CDF in the
same graph and I amusing the following codes. "z" is a vector and I just
need the part when z between 1.6 and 3.
plot(ecdf(z), do.points=FALSE, verticals=TRUE,
xlim=c(1.6,3),ylim=c(1-sum(z>1.6)/length(z), 1))
x <- seq(1.6, 3, 0.1)
lines(x,pgpd(x, 1.544,0.4373,-0.2398), col="red")
y
2005 Jul 08
1
Finite Mixture Models with logistic regression
Do we have any R package that can do analysis on finite mixture model with
logistic regression? Thanks
Faith
Feng Gao
Dept. of Statistics
Virginia Tech.
Email: fgao at vt.edu
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 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 Sep 26
2
quasi-random vector according to an independent graph
Dear R-users,
Is anyone aware of any function/package for generating a random vector from
a joint distribution defined by an independent graph? Or I have to work it
out myself?
Thanks.
Jinfang
------------------------------
Jinfang Wang, Associate Professor
Chiba University, Japan
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
1
ML optimization question--unidimensional unfolding scalin g
Alternatively, just type debug(optim) before using it, then step through it
by hitting enter repeatedly...
When you're done, do undebug(optim).
Andy
> From: Spencer Graves
>
> Have you looked at the code for "optim"? If you
> execute "optim", it
> will list the code. You can copy that into a script file and walk
> through it line by line to
2005 Jul 07
1
spurious regression in R
Hi:
I am trying to do a spurious regression in R but I
can not find the function. Anybody used it before? The
problem I have is try to do a regression with several
time series. An alternative is to use the GLS function
to fit the linear regression with the correlation
structure AR(3) for the response (or residual). I hope
the residuals after the GLS regression will be
independent judged by
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