Displaying 3 results from an estimated 3 matches for "skellam".
Did you mean:
shellam
2009 Nov 09
0
unexpected results involving the skellam distribution
Hi all,
I am new to R. I made this script that plots the
deviation of a skellam-distributed random variable
with respect to the skellam distribution.
I would expect to get random errors, but the plot
sistematically shows a non-random pattern (first a
peak and then a low). I don't know how to explain
this. Can somebody enlighten me??
require(skellam)
n <- 5000
lam1 &...
2009 Jul 02
2
constrained optimisation in R.
i want to estimate parameters with maximum likelihood method with contraints (contant numbers).
for example
sum(Ai)=0 and sum(Bi)=0
i have done it without the constraints but i realised that i have to use the contraints.
Without constraints(just a part-not complete):
skellamreg_LL=function(parameters,z,design)
{
n=length(z);
mu=parameters[1];
H=parameters[2];
Apar=parameters[3:10];
Dpar=parameters[11:18];
res=optim(par,skellamreg_LL,method="Nelder-Mead", hessian = FALSE, control=list(trace=1000,maxit=100000),z=z,design=x,)
___________________...
2009 Sep 27
3
CRAN (and crantastic) updates this week
CRAN (and crantastic) updates this week
New packages
------------
* bdoc (1.0)
Michael Anderson
http://crantastic.org/packages/bdoc
This package contains a function that will classify DNA barcodes as
well as a few test and reference data sets.
* bdsmatrix (1.0)
Terry Therneau
http://crantastic.org/packages/bdsmatrix
This is a special case of sparse matrices, used by coxme and