similar to: non homogeneous poisson process

Displaying 20 results from an estimated 10000 matches similar to: "non homogeneous poisson process"

2010 Mar 26
1
Poisson Lognormal
Hi R Users, I'm going to estimate via. ML the parameters in Poisson Lognormal model. The model is: x | lambda ~ Poisson(lambda) lambda ~ Lognormal(a,b) Unfortunately, I haven't found a useful package allowing for such estimation. I tried to use "poilog" package, but there is no equations and it's hard to understand what exactly this package really does. Using it I get the
2012 Jul 06
4
Poisson Ridge Regression
Dear everyone I'm dealing with a problem related to Poisson Ridge Regression. If anyone can help me in this regard by telling if any changes in the source code of "glm.fit" may help -- Regards Umesh Khatri
2008 Nov 06
2
Confidence limits for the parameter of the Poisson distribution
Hi all, So far I only know one way to get the confidence limit for the Poisson distribution is to use the look-up table given by the 2 parameter (the number of observation x and the confidence level, e.g. 95%) and the table is limit by the maximum number of observations (x <= 50). I know the formula to compute the CI, however, mathematically it is not easy to do it. So, anyone know an R
2009 Jul 14
1
Simulation functions for underdispered Poisson and binomial distributions
Dear R users I would like to simulate underdispersed Poisson and binomial distributions somehow. I know you can do this for overdispersed counterparts - using rnbinom() for Poisson and rbetabinom() for binomial. Could anyone share functions to do this? Or please share some tips for modifying existing functions to achieve this. Thank you very much for your help and time Shinichi
2007 Jun 13
1
Normal and Poisson tail area expectations in R
I am interested in R functions for the following integrals / sums (expressed best I can in text) - Normal: G_u(k) = Integration_{Lower limit=k}^{Upper limit=infinity} [(u -k) f(u) d(u)], where where u is N(0,1), and f(u) is the density function. Poisson: G(lambda,k) = Sum_{Lower limit=k}^{Upper limit=infinity} [(x-k) p(x, lambda)] where P(x,lambda) is the Poisson prob function with parameter
2009 Feb 02
2
logLik for poisson models
Dear all, I have a very basic question: how does the logLik function work for poisson models? Example: I simulate 20 observations from a Poisson distribution with mean 800. y <- rpois(20,800) model <- glm(y ~ 1, family=poisson()) logLik(model) I would like to know what's the exact formula the function logLik uses. I looked at ?extractAIC but I cannot sort it out. Can you please
2010 Oct 13
5
Poisson Regression
Hello everyone, I wanted to ask if there is an R-package to fit the following Poisson regression model log(\lambda_{ijk}) = \phi_{i} + \alpha_{j} + \beta_{k} i=1,\cdots,N (subjects) j=0,1 (two levels) k=0,1 (two levels) treating the \phi_{i} as nuinsance parameters. Thank you very much -- -Tony [[alternative HTML version deleted]]
2010 Jun 12
1
Displaying "homogeneous groups" in aov post-hoc results ?
Hello dear R-help mailing list, A friend of mine teaches a regression and experimental design course and asked me the following question. She is trying to find a way to display the "homogeneous groups" (after performing tukey test on an aov object). here's an example for what she means by "homogeneous groups": She did one way anova and got these results for tukey test:
2020 Mar 24
2
[RFC][AArch64] Homogeneous Prolog and Epilog for Size Optimization
Hello, I'd like to upstream our work over the time which the community would benefit from. This is a part of effort toward minimizing code size presented in here <https://llvm.org/devmtg/2020-02-23/slides/Kyungwoo-GlobalMachineOutlinerForThinLTO.pdf>. In particular, this RFC is about optimizing prolog and epilog for size. *Homogeneous Prolog and Epilog for Size Optimization, D76570
2020 Mar 24
2
[RFC][AArch64] Homogeneous Prolog and Epilog for Size Optimization
Hi Vedant, Thanks for your interest and comment. Size-optimization improves page-faults and a start-up time for a large application, which this enabling also followed. Even though I didn't see a large regression/complaint on a CPU-bound case, which is not a typical case for mobile workload, I wanted to be precautious of enabling it by default. However, as with default outlining case, I
2006 Jul 10
2
about overdispersed poisson model
Dear R users I have been looking for functions that can deal with overdispersed poisson models. According to actuarial literature (England & Verall, Stochastic Claims Reserving in General Insurance , Institute of Actiuaries 2002) this can be handled through the use of quasi likelihoods instead of normal likelihoods. However, we see them frequently in this type of data, and we would like to
2003 Jan 16
3
Overdispersed poisson - negative observation
Dear R users I have been looking for functions that can deal with overdispersed poisson models. Some (one) of the observations are negative. According to actuarial literature (England & Verall, Stochastic Claims Reserving in General Insurance , Institute of Actiuaries 2002) this can be handled through the use of quasi likelihoods instead of normal likelihoods. The presence of negatives is not
2002 Feb 20
2
Code for bivariate Poisson regression?
Dear RHelpers, Does anyone know of any R code to perform bivariate Poisson regression (including random effects)? Best wishes Simon Simon D.W. Frost, M.A., D.Phil. Department of Pathology University of California, San Diego Antiviral Research Center (Formerly: UCSD Treatment Center) 150 W. Washington St., Suite 100 San Diego, CA 92103 USA Tel: +1 619 543 8080 x275 Fax: +1 619 298 0177 Email:
2007 May 31
1
Conditional logistic regression for "events/trials" format
Dear R users, I have a large individual-level dataset (~700,000 records) which I am performing a conditional logistic regression on. Key variables include the dichotomous outcome, dichotomous exposure, and the stratum to which each person belongs. Using this individual-level dataset I can successfully use clogit to create the model I want. However reading this large .csv file into R and running
2004 Apr 13
2
Non-homogeneity of variance - decreasing variance
Hello all, I'm running very simple regression but face a problem of non-homogeneity of variance, but with a decreasing variance with increasing mean...I do not know how to deal with that. this relationship doesn't seem to be strong, but it's my first time to see something like that, and would like to know what to do if one day it becomes stronger. I tested just for fun some
2007 Nov 24
2
AIC and model selection; not a R question
Hi, I was wondering if someone could help me answer a question that is bound to come up in my Master's defense. I'm using AIC to select models and my question is how do I know that the models I developed a priori contain the 'best' models in the system. How do I not know that some models which I didn't include aren't actually the 'best' model?? Thanks so much
2011 Jul 02
1
Simulating inhomogeneous Poisson process without loop
Dear all I want to simulate a stochastic jump variance process where N is Bernoulli with intensity lambda0 + lambda1*Vt. lambda0 is constant and lambda1 can be interpreted as a regression coefficient on the current variance level Vt. J is a scaling factor How can I rewrite this avoiding the loop structure which is very time-consuming for long simulations? for (i in 1:N){ ... N <- rbinom(n=1,
2009 Feb 18
2
indicator or deviation contrasts in log-linear modelling
I am fairly new to log-linear modelling, so as opposed to trying to fit modells, I am still trying to figure out how it actually works - hence I am looking at the interpretation of parameters. Now it seems most people skip this part and go directly to measuring model fit, so I am finding very few references to actual parameters, and am of course clear on the fact that their choice is irelevant for
2010 Apr 14
1
Sig differences in Loglinear Models for Three-Way Tables
Hi all, I've been running loglinear models for three-way tables: one of the variables having three levels, and the other two having two levels each. An example looks like below: > yes.no <- c("Yes","No") > switch <- c("On","Off") > att <- c("BB","AA","CC") > L <- gl(2,1,12,yes.no) > T <-
2002 Dec 10
1
autoregressive poisson process
Dear R users, I am trying to find a package that can estimate an autoregressive model for discrete data. I am imagining a Poisson or Gamma process in which the mean (say mu) follows a process such as mu_t = a + b*x + c*mu_{t-1} Suppose I have data on the time-series Poisson outcomes and x and would like to obtain ML estimates for b and c. Does anyone know of a package that can do this