Displaying 10 results from an estimated 10 matches similar to: "Simple censored quantile regression question"
2001 Aug 30
1
MCMC coding problem
Dear All,
I am trying to convert some S-plus code that I have to run MCMC into
R-code. The program works in S-plus, but runs slowly.
I have managed to source the program into R. R recognizes that the program
is there; for example, it will display the code when I type the function
name at the prompt. However, the program will not run. When I try to run
the program, I get the following error
2006 Jan 19
2
Tobit estimation?
Folks,
Based on
http://www.biostat.wustl.edu/archives/html/s-news/1999-06/msg00125.html
I thought I should experiment with using survreg() to estimate tobit
models.
I start by simulating a data frame with 100 observations from a tobit model
> x1 <- runif(100)
> x2 <- runif(100)*3
> ystar <- 2 + 3*x1 - 4*x2 + rnorm(100)*2
> y <- ystar
> censored <- ystar <= 0
2002 Feb 11
0
profile
I am running 1.3.1 on a Windows (NT 4.0) machine. I've fit a nonlinear
model intended to predict crop yield from nutrient information, and want to
use the profile function. If I type say,
profile(simparj.fm)
I get the following error message:
"Error in prof$getProfile(): number of iterations exceeded maximum of
5.25515e-308"
I used the profiler function to profile simparj,fm step
2012 Oct 25
2
How to extract auc, specificity and sensitivity
I am running my code in a loop and it does not work but when I run it
outside the loop I get the values I want.
n <- 1000; # Sample size
fitglm <- function(sigma,tau){
x <- rnorm(n,0,sigma)
intercept <- 0
beta <- 0
ystar <- intercept+beta*x
z <- rbinom(n,1,plogis(ystar))
xerr <- x + rnorm(n,0,tau)
model<-glm(z ~ xerr, family=binomial(logit))
2012 Oct 20
1
Logistic regression/Cut point? predict ??
I am new to R and I am trying to do a monte carlo simulation where I
generate data and interject error then test various cut points; however, my
output was garbage (at x equal zero, I did not get .50)
I am basically testing the performance of classifiers.
Here is the code:
n <- 1000; # Sample size
fitglm <- function(sigma,tau){
x <- rnorm(n,0,sigma)
intercept <- 0
beta
2009 Apr 23
2
Two 3D cones in one graph
Dear R-users:
The following code produces two cones in two panels. What I would like
to have is to have them in one, and to meet in the origin. Does anyone
have any good ideas how to do this?
Thanks for your help
Jaakko
library(lattice)
A<-matrix(ncol=2, nrow=64)
for(i in 0:63)
{
A[i+1,1]<-sin(i/10)
A[i+1,2]<-cos(i/10)
}
2012 Oct 26
0
Problems getting slope and intercept to change when do multiple reps.
library(ROCR)
n <- 1000
fitglm <- function(iteration,intercept,sigma,tau,beta){
x <- rnorm(n,0,sigma)
ystar <- intercept+beta*x
z <- rbinom(n,1,plogis(ystar))
xerr <- x + rnorm(n,0,tau)
model<-glm(z ~ xerr, family=binomial(logit))
*int*<-coef(model)[1]
*slope*<-coef(model)[2] # when add error you are suppose to get slightly
bias slope. However when I change
2008 Dec 16
1
Prediction intervals for zero inflated Poisson regression
Dear all,
I'm using zeroinfl() from the pscl-package for zero inflated Poisson
regression. I would like to calculate (aproximate) prediction intervals
for the fitted values. The package itself does not provide them. Can
this be calculated analyticaly? Or do I have to use bootstrap?
What I tried until now is to use bootstrap to estimate these intervals.
Any comments on the code are welcome.
2012 Sep 17
2
Problem with Stationary Bootstrap
Dear R experts,
I'm running the following stationary bootstrap programming to find the parameters estimate of a linear model:
X<-runif(10,0,10)
Y<-2+3*X
a<-data.frame(X,Y)
coef<-function(fit){
fit <- lm(Y~X,data=a)
return(coef(fit))
}
result<- tsboot(a,statistic=coef(fit),R = 10,n.sim = NROW(a),sim = "geom",orig.t = TRUE)
Unfortunately, I got this
2018 Jan 25
0
Problems getting nouveau to work with either Geforce GT710 or Geforce 9800GT on ARM Cortex-A9
Hi Ben,
Ok! I've removed nvidiafb from kernel config.
Now linux is able to boot with the msi Geforce GT 710 card and
eventually ends up displaying a slightly distorted lightdm login
screen. The mouse cursor moves, but never changes to typing cursor
mode when hovering the password input box, and I am also unable to
enter the password, some graphics glitches in the login box too. There
are