Displaying 20 results from an estimated 100 matches similar to: "GMM: "The covariance matrix of the coefficients is singular""
2011 Jan 03
1
Greetings. I have a question with mixed beta regression model in nlme.
*Dear R-help:
My name is Rodrigo and I have a question with nlme package
in R to fit a mixed beta regression model. The details of the model are:
Suppose that:*
*j in {1, ..., J}* *(level 1)*
*i in {1, ..., n_j}* *(level 2)*
*y_{ij} ~ Beta(mu_{ij} * phi_{ij}; (1 - mu_{ij}) * phi_{ij})
y_{ij} = mu_{ij} + w_{ij}
*
*with*
*logit(mu_{ij}) = Beta_{0i} + Beta_{1i} * x1_{ij} + b2 * x2_{ij}
2011 Jan 03
0
Greetings. I have a question with mixed beta regression model in nlme (corrected version).
*Dear R-help:
My name is Rodrigo and I have a question with nlme package
in R to fit a mixed beta regression model. I'm so sorry. In the last
email, I forgot to say that W is also a unknown parameter in the mixed
beta regression model. In any case, here I send you the correct formulation.
**
Suppose that:*
*j in {1, ..., J}* *(level 1)*
*i in {1, ..., n_j}* *(level 2)*
*y_{ij} ~
2010 May 18
1
Maximization of quadratic forms
Dear R Help,
I am trying to fit a nonlinear model for a mean function $\mu(Data_i,
\beta)$ for a fixed covariance matrix where $\beta$ and $\mu$ are low-
dimensional. More specifically, for fixed variance-covariance matrices
$\Sigma_{z=0}$ and $\Sigma_{z=1}$ (according to a binary covariate $Z
$), I am trying to minimize:
$\sum_{i=1^n} (Y_i-\mu_(Data_i,\beta))' \Sigma_{z=z_i}^{-1} (Y_i-
2012 Apr 16
1
eval a SYMSXP from C
Can someone offer some advice on how to properly evaluate a SYMSXP
from a .Call ?
I have the following in R:
variable xn, with an attribute "mu" which references the variable mu
in the global environment.
I know "references" is a loose term; mu was defined in this fashion as
a way to implement deferred binding:
foo <- function(x,mu) {
attr(x,"mu") <-
2013 Feb 20
2
'gmm' package: How to pass controls to a numerical solver used in the gmm() function?
Hello --
The question I have is about the gmm() function from the 'gmm' package
(v. 1.4-5).
The manual accompanying the package says that the gmm() function is
programmed to use either of four numerical solvers -- optim, optimize,
constrOptim, or nlminb -- for the minimization of the GMM objective
function.
I wonder whether there is a way to pass controls to a solver used
while calling
2011 Jul 29
0
GMM, panel data, functions lag() and diff()
I’m starting to use the GMM estimator with panel data in R. I´ve read the
document «Panel Data Econometrics in R: The plm Package» (Croissant and
Millo).
In Stata before using the functions lag() or diff() we must sort the data by
individual and by time. I would like to know if I have to do something like
this in R.
If you know any other interesting document about panel data in R please let
me
2010 Jul 02
0
GMM with covariance moment condicion
hello
I have covariance stacionary proces, and i want to estimate some parameter
of this proces via gmm.
My problem is with write "g" -function.
0 order autocovariance is not problem
1 and higher order autocavariance are problem, because add order from 0 mean
that I "loose" one "observacion"
if I have 100 observation and i am going to use mean, variance and first
2013 Feb 28
0
GMM for dynamic mdels: what if never passes Sargan test?
Hi! I am looking for some insight with this situation: what to do or how to
analyze when our models fitted with pgmm never pass Sargant test?
With my current dataset, I've been fitting different models and with all
possible combinations of lagged instruments, with all possible lag order
combinations, but no model passes Sargan test. I can not give up gmm here
as I have autocorrelation and
2003 Apr 30
0
Help on Regress GMM
I have a problem in estimating GMM estimators with constraints. How can I do this?
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2007 Jun 11
0
GMM estimation
Dear everyone:
I have to finish my thesis to graduate as Bs. in Economics.
I choose to estimate a New Keynesian Phillips Curve (NKPC) for Uruguay
using Generalized Moment Method (GMM).
I do not know programming or R but I would like to use it.
Should I use gee, geepack or gam?
Thanks in advance,
Sebasti?n.
***************************************
?Hola todos!
Para terminiar mi
2009 Jul 17
0
Inequality constraints in GMM estimation?
I have a relatively simple finance application of GMM. Given the moment
condition:
E[m*R]=0
where m=m[theta]
I would like to constrain m>0. Any ideas?
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2013 Jan 13
1
R error: system is computationally singular when building GMM model
Dear,
I built the generalized method of moments model to estimate the sales rank
in the bookstore using plm package in R.
The equation is:
data1.gmm <- pgmm(dynformula(lnsales_rank ~ ln_price + avg_ham_rate +
avg_spam_rate + num_of_ham+ num_of_spam + ship_code2 +ship_code3
+ship_code4+ ship_code5+ ship_code6 + ship_ code7, lag = list(0, 0, 0,
0,0,0,0,0,0,0,0,0), log =FALSE), data=data,
2012 Jul 31
0
Problems in using GMM for calculating linear regression
Hi,
I'm trying to use gmm package in order to calculate linear regression (I
need to use the gmm for other application and this is a prior test I'm
doing).
I've defined a function for linear regression with 2 variables (x[,1] holds
the y values, while x[,2:3] holds the x values):
function(tet, x)
{
m1 <- (x[,1] - (tet[1] + tet[2] * x[,2] + tet[3] * x[,3])) * x[,2]
m2 <-
2024 Nov 04
2
Invalid term in model formula with gmm after formula.tools is loaded
? Sun, 3 Nov 2024 12:53:52 +0100
Elys?e Aristide <ariel92and at gmail.com> ?????:
> Does that mean that I should send a new message? Or is it okay for
> this time?
No need to post it again. Did it help to replace the as.character()
method for formulas provided by 'formula.tools'? I see the problem is
already reported to the 'formula.tools' maintainer [*], so there
2008 May 27
2
GMM estimation
Hello there!!!
Sorry to bother you all with such question and difficulties that I have been
facing on.
Recently I have been searching for packages to run GMM estimatives with R.
I have been searching for such packages for a while, but since I am a new
user of R system,
my quest so far was unsucessful.
That´s why I had decided to ask to this forum. Hope that anyone could help
me!
I know that
2009 Nov 15
2
lme model specification
Dear all
this is a question of model specification in lme which I'd for which I'd greatly appreciate some guidance.
Suppose I have data in long format
gene treatment rep Y
1 1 1 4.32
1 1 2 4.67
1 1 3 5.09
. . . .
. . . .
. . . .
1 4 1 3.67
1 4 2 4.64
1 4 3 4.87
.
2024 Nov 03
1
Invalid term in model formula with gmm after formula.tools is loaded
Hi Ivan,
Thank you for your message. Does that mean that I should send a new
message? Or is it okay for this time?
Best,
Aristide
On Fri, Nov 1, 2024, 22:29 Ivan Krylov <ikrylov at disroot.org> wrote:
> Hi Aristide and welcome to R-help!
>
> Your message was a bit mangled [*]. It's best to compose messages to
> this mailing list in plain text. Otherwise (when composed in
2009 Oct 17
2
Recommendation on a probability textbook (conditional probability)
I need to refresh my memory on Probability Theory, especially on
conditional probability. In particular, I want to solve the following
two problems. Can somebody point me some good books on Probability
Theory? Thank you!
1. Z=X+Y, where X and Y are independent random variables and their
distributions are known.
Now, I want to compute E(X | Z = z).
2.Suppose that I have $I \times J$ random number
2011 Oct 25
1
regression using GMM for mulltiple groups
Inthe code below I was trying to to obtain the GMM estimates for CAPM
(REGRESSION) for 36 stocks each have 180 observations,however it only gives
me one output rather than 36.
In SAS i would just put in a *By statement*. I have a variable TICKER that
categorize them into 36 groups.
*How can I obtain all 36 output instead of just one.*
**
2024 Oct 30
1
Invalid term in model formula with gmm after formula.tools is loaded
Hi everyone,
I am using the gmm function from the gmm package and encountered an
unexpected error. No model can be estimated if I load formula.tools?I need
to restart R each time. Here is a simple reproducible example:
*library(gmm)data(Finance)r <- Finance[1:300, 1:10]rm <- Finance[1:300,
"rm"]rf <- Finance[1:300, "rf"]z <- as.matrix(r-rf)zm