search for: skellam

Displaying 3 results from an estimated 3 matches for "skellam".

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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