similar to: Newton-Raphson

Hello, Does anyone know whether the gls function in the nlme library uses the Newton-Raphson or EM algorithm to find the restricted log-likelihood or maximum log-likelihood estimates? Brendan Klick bklick@jhsph.edu [[alternative HTML version deleted]]

Hi, Does anyone know if there is a function to find the maximum likelihood estimates of glm using Newton Raphson metodology instead of using IWLS. Thanks Valeska Andreozzi -------------------------------------------------------- Department of Epidemiology and Quantitative Methods FIOCRUZ - National School of Public Health Tel: (55) 21 2598 2872 Rio de Janeiro - Brazil

Dear Mr.Zeileis & all. (1)     Thx for your reply. Yes, I am talk about the function zeroinfl() from the package "pscl". I want to use Newton Raphson to get parameter             estimation ZINB, so I try this: ----------------------------------------------------------------------------------------------------------------------------------         > zinb <- zeroinfl(y

Hi, Is there available package on the optimization function using Newton-Raphson method (iterative quadratic approximation)? I have been using the 'optim' function in R and found it really unstable (it depends heavily on the initial values and functional forms). If I have to code it by myself, can I get some advice on how to start (any good reference or sample code)? I really

Hi, Is there a routine available in R for the Newton-Raphson method for simulataneous equations in several unknowns? Thanks Robert -- Robert J. Chandran Department of Botany 3506 Miller Plant Sciences Building University of Georgia Athens, GA 30602 Phone: (706)-583-0943 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read

Dear all.. I have a respon variable y. Predictor variable are x1, x2, x3, x4, x5 (1) What is the syntax to get paramater estimation of ZINB Model by Newton Raphson (not BFGS) (2) What syntax to plot probability of observed & predicted of ZINB Thx. Regards Krist. [[alternative HTML version deleted]]

Hi I would like to use the newton raphson method to find the root if the equation x^3-0.165*x+0.0003993 without using any readliy available program in r but instead by writing my own code and loop. the problem is that i really cant understand how to write the loop so that it keeps using the last calcualted values. if anyone could help me or give me some tips i would deeply appriciate it thanks

I have not included the previous postings because they came out very strangely on my mail reader. However, the question concerned the choice of minimizer for the zeroinfl() function, which apparently allows any of the current 6 methods of optim() for this purpose. The original poster wanted to use Newton-Raphson. Newton-Raphson (or just Newton for simplicity) is commonly thought to be the

I have the following function for which I need to find the root of a: f <- function(R,a,c,q) sum((1 - (1-R)^a)^(1/a)) - c * q To give context for the problem, this is a psychometric issue where R is a vector denoting the percentage of students scoring correct on test item i in class j, c is the proportion correct on the test by student k, and q is the number of items on the test in total. I

Hi, I'd like to use PSTN and analogic telephone with a Asterisk server which works on a LAN connected to the outside with fiber optic, on which voice stream passes too. Do I need some particular solution, some particular card to make it works or I just need a Digium or similar fxo card? Thanks, Bob __________________________________________________________________ Tiscali ADSL Senza Canone,

hi, i've a question. is it possible to buy digium x100p card from italy in some store (also online) without ordering it from USA? on more, did anyone buy a modem with intel chipset 537 or md3200 and where (in italy)? Thanks __________________________________________________________________ Tiscali ADSL Senza Canone, paga solo quello che consumi! Non perdere la promozione valida fino al 27

Hi, to register my Asterisk with a SIP provider I use the following syntax, as shown in the default sip.conf: register => 2345:password@sip_proxy where [sip_proxy] type=peer context=from-messagenet host=sip.messagenet.it port=5061 <------------- please note this one!!! 5061 is provider's port I have to register to. This also would work for me: register =>

Dear all, I am using the function 'D' in the 'stats' package to perform symbolic derivation. This works very well and it is much faster than e.g. Mathematica (at least for my purposes). First, I would like to thank the development team for this excellent function. However, I run into trouble in some cases, particularly when I am to do some operations on long expressions

I am examining the following nlme model. asymporig<-function(x,th1,th2)th1*(1-exp(-exp(th2)*x)) mod1<-nlme(fa20~(ah*habdiv+ad*log(d)+ads*ds+ads2*ds2+at*trout)+asymporig(da.p,th1,th2), fixed=ah+ad+ads+ads2+at+th1+th2~1, random=th1+th2~1, start=c(ah=.9124,ad=.9252,ads=.5,ads2=-.1,at=-1,th1=2.842,th2=-6.917), data=pca1.grouped) However, the two random effects (th1 and th2)

How to use "contour" function? I type "contour(th1,th2,SumofSquares,levels=c(seq(1000,4000,200)))" But I didn't see contour in the plot, I guess it is because my data is so big that contour is out of range. Does anybody know how to fix this problem? here th1 is a 1x101 array(158741.8-298529.6) th2 is another 1X101 array(-0.0058352269-0.2093140935) SumofSquares is a

Can some kind person point out my error here? I'm trying to set up a grid for a countour plot of a likelihood function. > u <- rnorm(20,9.5,2.5) > # sample of size 20 from N(9.5,2.5^2) > loglik <- function(th1,th2) { + n <- length(u) + -(n/2)*log(2*pi*th2^2)-0.5*sum((u-th1)^2/th2^2) + } > x <- seq(4.5,14.5,len=50) > y <- seq(0.5,6,len=50) > f <-

Hi everyone! I meet one problem when embedding R in C code, when I run the the R code in one child thread , it always print error info: Error: C stack usage is too close to the limit I also try to set R_CStackLimit = (uintptr_t)-1 to disable the C stack check as the R-exts doc say, but it still does not work, the error info still exist. Besides it is interesting that if i

Hi Everyone: I installed CentOS 4.4 on a new Dell 2950 using the server cd. No errors during the installation and no errors on bootup when loading the Eth0 or Eth1 interfaces. I currently have iptables stopped and selinux disabled. The interfaces have been given a static ip (192.168.1.x). the subnet is 255.255.255.0 and the gateway is 192.168.1.1. I can not ping any device on my network

Hi I wrote a function implementing an algoritm for simulation of spatial sampling plans (using geoR). I'm using a range of parameters to perform several simulation and sometimes this parameters create function errors wich cause the algoritm to stop. How can I avoid this ? Below there's a small example that I made to study the problem but I was not able to solve it. I've tried

Dear all, Are there any packages can estimate the partial linear model. Or any one can give me any suggestions. Many thanks in advance. Jin