Displaying 3 results from an estimated 3 matches for "minusloglik".
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2006 Feb 13
2
Sweave, mle and curve
...ing result with the following code, lec4.Snw:
\documentclass[a4paper,12pt]{article}
\usepackage[latin1]{inputenc}
\title{Maximum likelihood}
\author{G伱伓ran Brostr伱伓m}
\begin{document}
\maketitle
<<fig=TRUE>>=
## Simulate Y:
n <- 25
Y <- sum(rpois(n, lambda = 1))
Y
## Define minusloglik:
minusloglik <- function(theta) n * theta - Y * log(theta)
curve(minusloglik, 0.2, 2, xlab = "theta")
library(stats4)
cat("Y is now ", Y, "\n")
fit <- mle(minusloglik, start = list(theta = Y/n))
summary(fit)
@
\end{document}
In R, I get:
> Sweave("le...
2011 Apr 28
1
DLSODA error
...- c(3.02, 2.88, 2.91, 2.83, 2.85, 2.88, 2.91, 2.90, 2.94, 3.09, 3.17,
3.14, 3.37, 3.40, 3.50, 3.58, 3.55, 3.70, 3.90, 3.77)
c10 <- c(4.39, 4.22, 4.27, 4.21, 4.25, 4.34, 4.47, 4.40, 4.46, 4.64, 4.73,
4.60, 4.87, 4.96, 5.09, 5.10, 5.08, 5.26, 5.54, 5.37)
T = 20
#definining -log-likelihood function
minusloglik <- function(K_vv, K_rv, K_rr, theta_v, theta_r, Sigma_rv,
Sigma_rr, lambda_v, lambda_r){
# #solving ODEs as functions of "parameters"
parameters <- c(K_vv,
K_rv,
K_rr,
theta_v,
theta_r,...
2013 Mar 05
0
Error message from flexsurvreg
...ous work of
my colleagues on similar projects, am trying to estimate an AFT model with
a generalized gamma distribution. When I execute the following code:
>flexsurvreg(timesurv ~ cycles + rcycle + cyctime, dist="gengamma")
I get the following error message:
Error in optim(optpars, minusloglik.flexsurv, t = Y[, "time"], dead = Y[,
:
non-finite finite-difference value [4]
I get an almost identical error (a 3 in the brackets instead of a 4) if I
use the dist = "weibull". But have no problems when I run survreg with
Weibull distribution on the same data.
I've s...