Displaying 20 results from an estimated 300 matches similar to: "Simulating correlations with varying sample sizes"
2007 Aug 07
2
Varying case sensitivity
Hi all,
I''m using ferret 11.4 together with acts_as_ferret and I''ve indexed the
geonames.org country files. These files contain worldwide locations in
UTF-8 with all their different spellings each.
Model definition is like this:
class location
acts_as_ferret :fields => {:location_names => {}}, :single_index =>
true
...
end
The instance method location_names
2003 Sep 10
0
Multivariate Kalman filter with time-varying coefficients
Hi
Does anyone know of any R code for estimating a *multivariate* state
space model using a Kalman filter where the output matrix H(t) is
time-varying but predictable (i.e. measurable w.r.t information at time
t-1) in the observation equation
y(t) = H(t) z(t) + R w(t)?
[Here y(t) are the observations, z(t) is the state variable, w(t) the
observation error and R R' the observation error
2009 Mar 01
1
gamm (mgvc) and time-varying coefficient model
Dear R users,
I have repeated measurements on individuals. I want to estimate the
time-varying effect of a factor variable X (taking three levels), e.g. a
model in the spirit of Hastie and Tibshirani (1993).
I am considering using the package "mgvc" which implements generalized
additive models, especially the function gamm, which estimates
generalized additive mixed models, and thus,
2008 May 28
0
multistate survival analysis w/ time varying covariates
Hi, I've seen in the NestCohort package that one can do a hazard model with a
binary outcome using covariates. I am interested in multistate hazard models
with time-varying covariates, but can't seem to find this already implemented
in an R package. Is this included somewhere but called something else? I feel
like I've looked all over.
Thanks!
Michaela Gulemetova-Swan
2006 Sep 14
1
time varying covariates
Hello,
I am trying to model an intensity function with time-varying covariates.
Before, I have successfully defined a log likelihood function for a
Power-Law Process (lambda(t)=alpha*beta*t^(beta-1)) with two paramters
and no covariates for a repairable systems with failure times (t).
This function was maximized with R optim. No problem!
But now I want to include a covariate indicating a
2010 Sep 28
0
Time invariant coefficients in a time varying coefficients model using dlm package
Dear R-users,
I am trying to estimate a state space model of the form
(1) b_t = G * b_t-1 + w_t w_t ~ N(0,W)
(2) y_t= A' * x_t + H' * b_t + v_t v_t ~ N(0,V)
(Hamilton 1984: 372)
In particular my estimation in state space form looks like
(3) a3_t = 1 * a3_t-1 + w_t w_t ~ N(0,W)
(4) g_t = (a1, a2) * (1, P_t)' + u_t * a3_t + v_t v_t ~ N(0,V)
where g_t is the
2008 Mar 26
0
recursive multivariate filter with time-varying coefficients
Hi,
I've been searching CRAN and the web for a recursive multivariate
filter with time-varying coefficients.
What I mean is the following:
I have a series of square matrices A_t
an initial value vector y_0
and I need to compute
y_t =A_t%*%y_t-1
As these y_t may diverge quickly and/or lead to underflow problems,
the y_t need to be scaled by eg
y_t =y_t/sum(y_t-1)
Is anyone aware
2001 Nov 14
0
CQB & links of varying capacity
Hi,
I''ve been reading lots of documents and examples of setting up traffic
shaping, and found that they _all_ refer to specific bandwidths for queues.
I am using a dialup connection, and therefore can connect at different
rates, and also have a dynamically changing ''bandwidth'' dependent on
compression.
What I want to do is to specify that interactive traffic (telnet,
2005 May 23
0
Left truncation in shared frailty models with time-varying covariates
Hi!
I want to estimate a shared gamma frailty model with left truncated data. I use a parametric baseline hazard so that I can use
simple ML estimation. As I have a big data set it is ok to assume piecewise constant baseline hazards.
As my data are left truncated I have modified the definition of the risk set.
Do I also have to modifiy the frailty distribution if I have left truncated data?
2006 Oct 23
0
Construction of Dataset for time varying COXPH analysis
Question: When survfit() function is used upon a coxph object, the 'n' returned is vastly smaller (n=6) than the number of distinct loans in the dataset used.
I am trying to estimate a Cox proportional hazards model for a set of loans (over 6000) using using time varying covariates. For this 6000+ loans, I have some 62,000 different vectors representing the loans at different periods of
2014 Jan 29
0
[PATCH] nv30: report the correct max varying limit
nvfx_fragprog_assign_generic only allows for up to 10/8 texcoords for
nv40/nv30. This fixes compilation of the varying-packing tests (although
they still fail).
Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
Cc: 9.1 9.2 10.0 <mesa-stable at lists.freedesktop.org>
---
src/gallium/drivers/nouveau/nv30/nv30_screen.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git
2018 Sep 28
0
multiple mounts each varying bitrates
I just realised my previous email didn't go to the list for some reason.
Here it is again:
Currently, I have three liquadsoap ".liq" files, and they all look very
similar to this:
-------- 8< --------
jake at beastie:/etc/liquidsoap$ cat jake.liq
#!/usr/bin/liquidsoap
#set("log.file.path","/tmp/basic-radio.log")
def my_request_function() =
# Get the
2003 Jan 31
2
Varying texts in expression(paste())
Hi,
I am using R a lot to make plots relating to radioactivity, I am often using
expression() to label the plots with nuclide names written with
superscripts, e.g.
expression(paste("Releases of ", { }^{99},Tc," (TBq/year)"))->ywtext
But, is there any simple way to change the number and name of the nuclide
through a variable? I tried
nuccode=expression({ }^{99},Tc)
2004 Apr 07
1
Time Varying Coefficients
I'd like to estimate time varying coefficients in a linear regression using
a Kalman filter.
Even if the Kalman Filter seems to be available in some packages I can't
figure out how to use it to estimate the coefficients.
Is there anyway to do that in R?
Any help appreciated
Thanks
2006 Apr 03
2
testing proportional hazard in a Cox model including a time-varying covariate
I am using a syntax like coxph(Surv(start, stop, event) ~ X, data) to estimate the effect of X, which may change at each measurement (every 6 months). Is there anyone who knows a way to test the proportional hazard assumption in that case?
Thank you in advance
Jean-François Boudreau
Sherbrooke University
[[alternative HTML version deleted]]
2007 Jan 22
1
Time-varying correlation calculation
Dear R useres,
I'm interested in getting a series of time-varying correlation, simply between two random variables.
Could you please introduce a package to do this task?
Thank you so much for any help.
Amir
---------------------------------
Don't pick lemons.
[[alternative HTML version deleted]]
2007 Mar 16
1
cumsum over varying column lengths
Folks,
I have a matrix of historicalReturns, where entry (i, j) is the daily return
corresponding to date i and equity j. I also have a matrix startOffset,
where entry (1, k) is the row offset in historicalReturns where I entered
into equity k.
So we have that NCOL(startOffset) = NCOL(historicalReturns).
Now I would like compute for each column in historicalReturns, the
cumulative return
2007 Jul 12
0
time-varying recursive filter - vectorized
A question about vectorized operations (avoiding loops, for speed)...
I need to run a simple recursive (autoregressive) filter with a
time-varying coefficient. It is just a one-step recursive filter, so
it would be an exponential decay if the filter was constant.
I just want to do this, where 'x' is the data and 'w' is the weight to
apply to the previous time step:
x <- c(1,
2009 Jun 28
2
Fold function with several time varying covariates
Hi
I'm trying to use the fold function as described here:
http://cran.r-project.org/doc/contrib/Fox-Companion/appendix-cox-regression.pdf Page9
It does say that you can use this when you have more than one time varying covariate: in the description of the argument cov it says:
"cov: A vector giving the column numbers of the time-dependent covariate in data, or a list of vectors
if there
2010 May 22
0
Modeling time varying effects in with cph: how to ?
Dear R users,
I know, this is the second time i return on this topic. Sorry, but this
analysis is of great value for me, and i hope someone can help me.
I need to model a time-varying effect in a Cox model. Briefly explained
here:
http://books.google.com/books?id=9kY4XRuUMUsC&lpg=PP1&hl=it&pg=PA147#v=onepage&q&f=false