Displaying 4 results from an estimated 4 matches for "xi0".
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x00
2005 Mar 16
0
Are there any R packages that can deduce causal relationship between variables?
Hi netters.
Assume Y = {Y1,.....Yn} and X = {X1......Xm}, where Yi and Xi are random
variables that can take on discrete values from V={0,1,2}.
Each Yi in Y has some (0-k) parent variables in X, which means given the
values of the parent variables (Xi0....Xik) the values of Yi is set. Yi =
F(Xi0,...Xik), where F is a mapping function from parents to sons.
Considering there are some noise in the data, we can put it in a
probabilistic way: the parents and sons have the joint probability
distribution P(Yi) = P(Yi|Xi0...Xik).
Now I have a traini...
2009 Aug 20
1
Understanding R code
...hat is
1. par.ests <- optimfit$par
2. fisher <- hessb(negloglik, par.ests, maxvalue=maxima);
3. varcov <- solve(fisher);
4. par.ses <- sqrt(diag(varcov));
Thanks a lot,
fit.GEV <- function(maxima)
{
sigma0 <- sqrt((6. * var(maxima))/pi)
mu0 <- mean(maxima) - 0.57722 * sigma0
xi0 <- 0.1
theta <- c(xi0, mu0, sigma0)
#10/5/2007: removed assign() for maxima.nl
#10/5/2007: passed additional parameter to avoid using assign()
negloglik <- function(theta, maxvalue)
{
-sum(dGEV(maxvalue,theta[1],theta[2],abs(theta[3]),logvalue=TRUE));
}
#10/5/2007: passed additional 4th...
2000 May 02
2
Variable names in model formula
...an wrote:
>I have the following problem. I have survival data (time, status) along
>with several covariates (X1, X2,..., Xn). I want to fit a Cox model for
>each of the covariate (univariately) and obtain the fitted probability of
>survival at a fixed time point t0 and covariate value Xi0. I tried to do
>this in a for loop where the index is the variable name as follows
>
>covnames <- names(...)
>for (covi in covnames) {
> survout <- coxph(Surv(time,status) ~ covi, data = dataname)
> print(summary(survfit(survout,newdata),t0))
>}
You could try
covname...
2000 Apr 30
0
Help Need with aov()
Hi there,
I'm using R1.0.1 Windows 98.
This file contains some inputs and an aov function code. Can someone
check it for me? Somehow I got completely different answer when typing
them in R and in Splus.
Splus gives me this:
> summary( Turnip.aov )
Error: Blocks
Df Sum of Sq Mean Sq F Value Pr(F)
Residuals 3 163.7367 54.57891
Error: Plots %in% Blocks