Displaying 20 results from an estimated 52 matches for "e_".
Did you mean:
_e
2003 Jun 19
2
Fitting particular repeated measures model with lme()
...quot;teacher effect" applies to only one year. One can think of the first
score on the student as a score from a prior year (for which I have no
teacher links), and the second score is from the current year and is
linked to the teacher. The model for student j in class i is:
Y_{ij0} = a_0 + e_{ij0}
Y_{ij1} = a_1 + b_i + e_{ij1}
with Var(b_i) the teacher variance component and Cov(e_{ij0},e_{ij1})
unstructured. That is, if the data are organized by student, the "Z"
matrix in the usual linear mixed model notation has every other row
equal to a row of zeros.
I am wondering whet...
2002 Mar 29
1
help with lme function
Hi all,
I have some difficulties with the lme function and so this is my problem.
Supoose i have the following model
y_(ijk)=beta_j + e_i + epsilon_(ijk)
where beta_j are fixed effects, e_i is a random effect and
epsilon_(ijk) is the error.
If i want to estimate a such model, i execute
>lme(y~vec.J , random~1 |vec .I )
where y is the vector of my data, vec.J is a factor object and vec.I
is the vector for the i indice.
N...
2007 Mar 05
1
Heteroskedastic Time Series
...series modelling, but my requirement seems to fall just
outside the capabilities of the arima function in R. I'd like to fit an
ARMA model where the variance of the disturbances is a function of some
exogenous variable. So something like:
Y_t = a_0 + a_1 * Y_(t-1) +...+ a_p * Y_(t-p) + b_1 * e_(t-1) +...+ b_q *
e_(t-q) + e_t,
where
e_t ~ N(0, sigma^2_t),
and with the variance specified by something like
sigma^2_t = exp(beta_t * X_t),
where X_t is my exogenous variable. I would be very grateful if somebody
could point me in the direction of a library that could fit this (or a
similar...
2001 Oct 09
1
PROC MIXED user trying to use (n)lme...
...put out into a SAS data set.
How do I do the same with lme-objects? For example, I can see the
estimated variance matrix when typing the name of the lme-object,
but that does not give me a "handle" on the matrix.
2) I am trying to fit a mixed model, say
y_{ij} = X_{ij}\beta + U_i + e_{ij}
where Y_{ij}, U_i and e_{ij} all are D-dimensional, and U_i ~
N_D(0,G), and e_{ij} ~ N(0,R). This is easy to do in proc mixed by
including a factor keeping track of how the elements of y_{ij} are
"stacked" on top of each other. This factor is then used in the
model, the random and th...
2010 Aug 21
1
How to find residual in predict ARIMA
...eHuron,order=c(1,0,1))
then the function predict() can be used for predicting future data
with the model:
LakeH.pred <- predict(Lake.fit,n.ahead=5)
I can see the result LakeH.pred$pred and LakeH.pred$se but I did not
see residual in predict function.
If I have a model:
[\
Z_t = Z_{t-1} + A + e_t + B*e_{t-1}
\]
How could I find $e_t$ dan $e_{t-1}$ ?
Best, XY
2001 Feb 08
2
dnbinom(,size<1,)=0 (PR#842)
...r_ p[1]
th_ p[2]
ll _ -sum(x[1:max(kk)]*log(dnbinom(kk[-length(kk)],r,th))) -
x[length(kk)]*log(1-pnbinom((max(kk)-1),r,th))
return(ll)
}
a_ nlm(fn,p=c(.9,.5),hes=T)
est_ a$est
phat_ c(dnbinom(kk[-length(kk)],est[1],est[2]),
1-pnbinom((max(kk)-1),est[1],est[2]))
E_ n*phat
chi2_ sum((x-E)^2/E)
cat('Chi2 goodness-of-fit = ',chi2,'\n')
cat('P-value=',1-pchisq(chi2,df=length(kk)-1-2),'\n')
print(cbind(O=x,E=round(E,1),err=round((x-E)^2/E,1)))
===========================================
At 02:31 PM 2/8/01 +0000, Mark Wyatt wrote:...
2011 Jan 06
2
Waaaayy off topic...Statistical methods, pub bias, scientific validity
Folks:
The following has NOTHING (obvious) to do with R. But I believe that
all on this list would find it relevant and, I hope, informative. It
is LONG. I apologize in advance to those who feel I have wasted their
time.
http://www.newyorker.com/reporting/2010/12/13/101213fa_fact_lehrer
Best regards to all,
Bert
--
Bert Gunter
Genentech Nonclinical Biostatistics
2012 Mar 24
0
NLME error model with several responses
Hi!
I am using the NLME package for R to modeling glucose-insuline
response with Bergman's model, very similar to the example in the
documentation for the NLME package.
My question concerns the model for the residuals. I use a proportional
model , Var(e_{ij})=(sigma_g*G(t))^2 for the glucose response and
Var(e_{ij})=(sigma_i * I(t))^2 for the insulin response. Hence I have
a varPower model, but I know that the power coefficient is 2, but with
different sigma coefficients for the two responses.
If I fit a model I get an estimation of the standard d...
2008 Oct 12
1
Siemens Series A?
...hemselves, or is there any chance of hooking one
up? Siemens (a v large business) aren't mentioned on the Compatibility
Page: http://www.networkupstools.org/compat/stable.html But, their
Masterguard brand is:
http://www.medical.siemens.com/webapp/wcs/stores/servlet/CategoryDisplay~q_catalogId~e_-11~a_categoryId~e_1014490~a_catTree~e_100010,1012315,1014543,1014490~a_langId~e_-11~a_storeId~e_10001.htm
Any ideas much appreciated.
Regards,
Morgan.
--
Getting errors: "There are problems with the signature" (or similar)?
Update your system by installing certificates from CAcert Inc,...
2006 Apr 11
1
type II and III Sum square whit empty cells
Dear all
I need to run an anova from a factorial model
y_{ijk}=\alpha_i+\beta_j+(\alpha\beta)_{ij}+e_{ijk}
and calculate type II and III sums of square, but I have an empty
cells, so anova function from package car fail. (I believe)
y<-c(7,13,6,10,8,11,8,3,7,5,65)
a<-as.factor(c(1,1,2,2,3,3,3,1,1,1,2))
b<-as.factor( c(rep(1,7),rep(2,4)) )
table(b,a) # cell (2,3) is empty
mod<-lm(...
2004 Apr 28
4
numericDeriv
Dear All,
I am trying to solve a Generalized Method of Moments problem which
necessitate the gradient of moments computation to get the
standard errors of estimates.
I know optim does not output the gradient, but I can use numericDeriv to
get that. My question is: is this the best function to do this?
Thank you
Jean,
2012 Oct 27
0
[gam] [mgcv] Question in integrating a eiker-white "sandwich" VCV estimator into GAM
...e
econometrics sense of the term -- an individual-specific intercept. I
also want to model the continuous variables flexibly -- I have no good
priors on the proper specification for the function form. The model is
the following:
y_{it} = \alpha_i + \beta_1(T_{it}) + f(continuous.vars_{it}) + e_{it}
To control for unobserved time-invariant heterogeneity, I want to
de-mean the data as follows:
y_{it}-\bar{y_i} = \beta_1(T_{it}-\bar{T_i}) +
f(continuous.vars_{it}-\bar{continuous.vars_i}) + e_{it} - \bar{e}_i
Fitting the demeaned model should give me coefficient estimates equal to
the n...
2014 Nov 13
0
Boot fails in a VMware player VM - syslinux 6.03
...ed to a (USB) (flash) drive, which then can be used to
boot BIOS systems; and,
C_ can be dd'ed to a (USB) (flash) drive, which then can be used to
boot UEFI systems; and,
D_ can be dd'ed to a (USB) (flash) drive, which then can be used to
boot either/both BIOS systems or UEFI systems.
E_ can be expanded (I mean, its content) onto a (USB) (flash) drive
with GPT and a FAT ESP (and legacy "MBR"), which then can be used to
boot either/both BIOS systems or UEFI systems.
The possibility to perform #B/#C/#D/#E (in addition to #A) depends on
the content of the isohybrid image...
2013 Jan 14
2
Reports from 5.00
...ready solved in git, but I have not re-tested
it.) Getting out from HDT (version from Syslinux 5.00) using the
"exit" option (instead of rebooting) so to return back to syslinux
(menu.c32) fails (hangs). How to reproduce: boot to menu.c32, select
hdt.c32 entry, exit back to menu.c32.
E_ Under FreeDOS, SYSLINUX.COM doesn't seem to install ldlinux.*
(specially when used with "--directory"), and there are no ([error])
messages; not even when executed with no parameters, or with
"--help", or with "--version". The messages disappeared _after_
5.00-...
2014 Nov 13
2
Boot fails in a VMware player VM - syslinux 6.03
...ot; will not be capable of booting. This is one
> of the steps that corresponds to grub2, not to whichever other EFI
> bootloader you use (e.g. syslinux.efi).
So, it's not possible (yet?) to provide an hybrid ISO image able to
boot in UEFI and BIOS modes using Syslinux.
It took me _some_ time to realize that, but at least that helped me
understand a bit more Syslinux' and co features, thanks Ady and Thomas.
But as my goal is actually to to uniformize the tools and apperance for
booting an installer regardless of the firlwre's kind, instead I have
cooked an USB installer th...
2012 Nov 14
2
[LLVMdev] Generating code for Sequence expression
Hello.
In order to practice compiler writing, I am implementing a simple
compiler for the Tiger language. I am using llvm IR for the intermediate
representation.
Regarding llvm, I have started by reading the OCaml version of the LLVM
Tutorial, where a compiler for the kaleidoscope language is built.
The language I am implementing has a form of expression called "sequence
expression".
2006 May 19
0
how to estimate adding-regression GARCH Model
...ng fSeries package--the funciton garchFit and
garchOxFit
if adding a regression to the mean formula, how to estimate the model in
R? using garchFit or garchOxFit?
For example, Observations is {x,y}_t,there may be some relation between x
and y.
the model is
y_t=gamma0 + *gamma1*x_t*+psi*e_{t-1}+e_t the gamma1*x_t is
regression.
e_t=sqrt(h_t)*N(0,1)
h_t=alpha0+alpha1*e_t^2+beta*h_{t_1}~~~~~~~GARCH(1,1).
I didn't know how to estimate the model using function garchFit or
garchOxFit or other functions? because the argument in
garchFit/garchOxFit is formular.mean...
2007 Mar 17
1
Correlated random effects in lme
Hello,
I am interested in estimating this type of random effects panel:
y_it = x'_it * beta + u_it + e_it
u_it = rho * u_it-1 + d_it rho belongs to (-1, 1)
where:
u and e are independently normally zero-mean distributed.
d is also independently normally zero-mean distributed.
So, I want random effects for group i to be correlated in t, following an
AR(1) process.
Any idea of how to estim...
2004 Dec 29
3
gls model and matrix operations
...ade 4","Grade 5")
long<-reshape(data, idvar="stuid", varying=list(names(data)[2:5]),
v.names="score", direction="long")
long$time<-long$time-1
With these data I then use the gls function to estimate the following model
Y_{ti} = mu + beta(time) + e_{ti}
fm1 <- gls(score ~ time, long, correlation=corAR1(form=~1|stuid), method='ML')
>From here I can obtain V, the variance covariance matrix using the getVarCov function as follows:
var.mat<-getVarCov(fm1)
I<-diag(1,sample.size) # The following 2 steps are needed to make V c...
2005 Aug 27
2
Defining an ex-gaussian PDF
How does one define PDFs as yet undefined in R, such as the ex-
gaussian, the sum of two RVs, one exponential, one Gaussian? The PDF
would then be the convolution of an exponential PDF, dexp(), and a
normal, dnorm().
Kindly cc me in your reply to r-help.
Thanks,
_____________________________
Professor Michael Kubovy
University of Virginia
Department of Psychology
USPS: P.O.Box 400400