Displaying 20 results from an estimated 700 matches similar to: "solving for beta0 in a logsitic regression"
2000 Sep 23
1
logsitic prediction
Dear friends.
I have a paper (details below) examining the risk of renal failure after an
operation. A logistic regression was done, and the coefficients to two
regressors (age and creatinine) plus intercept with standard errors are
given. These coefficients must be dependent in estimation, and when no
details are given, I thought how I could most informatively get an
impression as to how
2005 Jun 30
1
ranking predictive features in logsitic regression
Hi
Is there some function R that multiplies each coefficient by the
standard deviation of the corresponding variable and produces a ranking?
Stephen
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2008 Sep 11
0
Loop for the convergence of shape parameter
Hello,
The likelihood includes two parameters to be estimated: lambda
(=beta0+beta1*x) and alpha. The algorithm for the estimation is as
following:
1) with alpha=0, estimate lambda (estimate beta0 and beta1 via GLM)
2) with lambda, estimate alpha via ML estimation
3) with updataed alpha, replicate 1) and 2) until alpha is converged to a
value
I coded 1) and 2) (it works), but faced some
2005 Dec 01
2
Minimizing a Function with three Parameters
Hi,
I'm trying to get maximum likelihood estimates of \alpha, \beta_0 and
\beta_1, this can be achieved by solving the following three equations:
n / \alpha + \sum\limits_{i=1}^{n} ln(\psihat(i)) -
\sum\limits_{i=1}^{n} ( ln(x_i + \psihat(i)) ) = 0
\alpha \sum\limits_{i=1}^{n} 1/(psihat(i)) - (\alpha+1)
\sum\limits_{i=1}^{n} ( 1 / (x_i + \psihat(i)) ) = 0
\alpha \sum\limits_{i=1}^{n} (
2010 Mar 25
0
help with breaking loops used to fit covariates in nlme model building procedure
Dear All
I'm attempting to speed up my model building procedure, but need some help with the loops I've created...please bear with me through the explanation!
My basic model call is something like:
m0sulf.nlme<-nlme(conc~beta0*exp(-beta1*day)+beta2*exp(-beta3*day),
data=m0sulf,
fixed=(beta0+beta1+beta2+beta3~1),
2008 Sep 12
1
Error in "[<-"(`*tmp*`, i, value = numeric(0)) :
I use "while" loop but it produces an errro. I have no idea about this.
Error in "[<-"(`*tmp*`, i, value = numeric(0)) :
nothing to replace with
The problem description is
The likelihood includes two parameters to be estimated: lambda
(=beta0+beta1*x) and alpha. The algorithm for the estimation is as
following:
1) with alpha=0, estimate lambda (estimate beta0
2011 May 04
1
hurdle, simulated power
Hi all--
We are planning an intervention study for adolescent alcohol use, and I
am planning to use simulations based on a hurdle model (using the
hurdle() function in package pscl) for sample size estimation.
The simulation code and power code are below -- note that at the moment
the "power" code is just returning the coefficients, as something isn't
working quite right.
The
2004 May 24
0
Seasonal ARIMA question - stat package (formerly ts)
To whom it may concern:
I am trying to better understand the functionality of 'R' when making
arima predictions to avoid any "Black Box" disadvantages.
I'm fitting a seasonal arima model using the following command (having
already loaded 'stat' package).
arimaSeason <-
arima(Data,order=c(1,0,1),seasonal=list(order=c(1,0,1),period=12))
I can then generate
2005 May 19
1
R 2.1.0 RH Linux Built from Source Segmentation Fault
Background:
I administer a cluster of RedHat EWS 3U4 Linux workstations at a university.
I built R 2.1.0 from source:
./configure \
--prefix=/sscc/opt/R-2.1.0 \
--with-blas=no \
2>&1 \
| tee NUInstall.configure
R is now configured for i686-pc-linux-gnu
Source directory: .
Installation directory: /sscc/opt/R-2.1.0
C compiler:
2008 Aug 22
2
WinBUGS with R
Dear Users,
I am new to both of things, so do not blame me too much...
I am busy with semiparametric regression and use WinBUGS to sample
posteriors.
The code to call Winbugs is as follows:
data <- list("y","X","n","m") #My variables
inits.beta <- rep(0,K)
inits.beta0 <- 0
inits <-
2007 Dec 04
1
Metropolis-Hastings within Gibbs coding error
Dear list,
After running for a while, it crashes and gives the following error message: can anybody suggest how to deal with this?
Error in if (ratio0[i] < log(runif(1))) { :
missing value where TRUE/FALSE needed
################### original program ########
p2 <- function (Nsim=1000){
x<- c(0.301,0,-0.301,-0.602,-0.903,-1.208, -1.309,-1.807,-2.108,-2.71) # logdose
2006 Aug 26
1
problems with loop
Dear all,
I am trying to evaluate the optimisation behaviour of a function. Originally
I have optimised a model with real data and got a set of parameters. Now I
am creating simulated data sets based on these estimates. With these
simulations I am estimating the parameters again to see how variable the
estimation is. To this end I have written a loop which should generate a new
simulated data
2010 Sep 08
3
[LLVMdev] Complex regalloc contraints
Hi Carlos, Jakob,
The PBQP allocator was designed to support a very wide range of constraints,
and can handle something like this easily.
Say you have 4 of these orX/irX registers, then for any pair of virtual
registers used in such an add instruction you would add the following
constraint matrix to the PBQP instance:
[ 0 inf inf inf ]
[ inf 0 inf inf ]
[ inf inf 0 inf ]
[ inf inf inf 0
2013 Jan 18
0
problem that arises after using the new version of "BRugs"
Respected Sir,
With reference to my mail to you and the reply mail
by you dated 9th and 16th January, 2013, I am sending the reproducible code
in the attached document named " MODIFIED ANS ". I am also attaching the
txt file named "hazModel", which is required to save in my documents folder
to run the program. The file also contains the error message
2012 Jul 02
1
How to get prediction for a variable in WinBUGS?
Dear all,I am a new user of WinBUGS and need your help. After running the following code, I got parameters of beta0 through beta4 (stats, density), but I don't know how to get the prediction of the last value of h, the variable I set to NA and want to model it using the following code.Does anyone can given me a hint? Any advice would be greatly appreciated.Best
2010 Sep 07
0
[LLVMdev] Complex regalloc contraints
On Sep 7, 2010, at 3:01 AM, Carlos Sanchez de La Lama wrote:
> The machine I am targeting has some special requirements for some
> operations, say:
>
> ADD or1, ir1, r5
>
> would add ir1 (input reg 1) and r5 and put the result in or1 (output reg
> 1). The point id that input and output regs have to go paired (this
> meaning an addition of ir1 with whatever always goes to
2010 Sep 07
2
[LLVMdev] Complex regalloc contraints
Hi all,
The machine I am targeting has some special requirements for some
operations, say:
ADD or1, ir1, r5
would add ir1 (input reg 1) and r5 and put the result in or1 (output reg
1). The point id that input and output regs have to go paired (this
meaning an addition of ir1 with whatever always goes to or1, or an in
general irX + whatever goes to orX).
AFAIK, InstrInfo.td only allow
2012 Dec 04
1
Winbugs from R
Hi,
I am trying to covert a Winbugs code into R code. Here is the winbugs code
model{# model’s likelihoodfor (i in 1:n){time[i] ~ dnorm( mu[i], tau ) # stochastic componenent# link and linear predictormu[i] <- beta0 + beta1 * cases[i] + beta2 * distance[i]}# prior distributionstau ~ dgamma( 0.01, 0.01 )beta0 ~ dnorm( 0.0, 1.0E-4)beta1 ~ dnorm( 0.0, 1.0E-4)beta2 ~ dnorm( 0.0, 1.0E-4)#
2010 Nov 30
1
StructTS with 2 seasons
Dear All,
I am trying to fit a structural time series model using the StructTS
function (package stats) with only 2 seasons (summer and winter). More
than 2 seasons work fine but with 2 seasons I get this error:
> fit <- StructTS(y.ts, type="BSM")
Error in T[cbind(ind + 1L, ind)] <- 1 : subscript out of bounds
I have looked at Prof. Ripley's 2002 RNews article but cannot
2011 Nov 14
0
Enquiry about 2nd-order interactions survival analysis
David's answers were correct. You are looking deep into the code when
there is no reason to to so.
1. h(t|(X=x,Z=z)) = exp(Beta0 + XZBeta1)
Most statisticians will tell you that this is an unwise model. The
reason is that if you replace X with "X+1" the fit changes, which is
almost never desirable. What if someone coded your dummy variable as
1/0 instead of 0/1 -- wouldn't