similar to: Prediction intervals for zero inflated Poisson regression

Dear R helpers, running the following code of a glm model of the family poisson, gives predicted values < 0. Why? library(MASS) library(stats) library(mvtnorm) library(pscl) data(bioChemists) poisson_glm <- glm(art ~ fem + mar + kid5 + phd + ment, data = bioChemists, family = poisson) predicted.values = predict(poisson_glm) range(predicted.values) Thank you in advance for any hints.

Hi all-- I am in the process of helping colleagues write up a ms in which we fit zero-inflated Poisson models. I would prefer plotting the rate ratios and 95% CI (as I've found Gelman and others convincing about plotting tables...), but our journals usually like the numbers themselves. Thus, I'm looking at a recent JAMA article in which both numbers and dotplot of RR and 95% CI are

I have a question for users of MCMCglmm that have experience implementing the zero-inflated poisson model. I find that the documentation, and previous questions, do not offer a lot of clear guidance on specifying and interpreting the zipoisson model. In particular, I see a lot of zero-inflated poisson examples that use the at.level(trait, x):variableName syntax. Specifically, the MCMCglmm

Are you referring to the zeroinfl() function in the countreg package? If so, I think predict(fm_zinb2, type = "zero", newdata = some.new.data) will give you pi for each combination of covariate values that you provide in some.new.data where pi is the probability to observe a zero from the point mass component. As to your second question, I'm not sure that's possible, for any

I am running a zero inflated regression using the zeroinfl function similar to the model below: fm_zinb2 <- zeroinfl(art ~ . | ., data = bioChemists, dist = "poisson") summary(fm_zinb2) I have three questions: 1) How can I obtain a value for the parameter pie, which is the fraction of the population that is in the zero inflated model vs the fraction in the count model? 2) For

Dear all, I would like to know if there is a function for sorting a data.frame based on one column. sort() does it for a single vector but not for the whole data. order() does it if there are relations between the columns but in my case it is simply a data.frame. Further, I would like to plot other data, pop.size<- c(800, 800, 1500, 1000, 158, 300, 740, 250, 2000, 1500, 250, 700)

Hi, I am a little confused at the output from predict() for a zeroinfl object. Here's my confusion: ## From zeroinfl package fm_zinb2 <- zeroinfl(art ~ . | ., data = bioChemists, dist = "negbin") ## The raw zero-inflated overdispersed data > table(bioChemists$art) 0 1 2 3 4 5 6 7 8 9 10 11 12 16 19 275 246 178 84 67 27 17 12 1 2 1 1

Hi, I am trying to replicate Lambert (1992)'s simulation with zero-inflated Poisson models. The citation is here: @article{lambert1992zero, Author = {Lambert, D.}, Journal = {Technometrics}, Pages = {1--14}, Publisher = {JSTOR}, Title = {Zero-inflated {P}oisson regression, with an application to defects in manufacturing}, Year = {1992}} Specifically I am trying to recreate Table 2. But my

I have this problem with R 2.6.1 and 2.7.1 (have not tried others) running on Windows XP: Html help has wrong links to help files. The index.html is correctly found from file:///C:/PROGRA~1/R/R-26~1.1/doc/html/index.html as well as the search engine file:///C:/PROGRA~1/R/R-26~1.1/doc/html/search/SearchEngine.html However, when I search for, say, "paste", I will be pointed to

R-users, My question is related to earlier posts about benefits of quadcore over dualcore computers; I am trying to setup a cluster of windows xp computers so that eventually I could make use of 10-20 cpu:s, but for learning how to do this, I am playing around with two laptops. I thought that the package snow would come handy in this situation, but to use snow, I would probably need to install

Hi, I am new to R. My problem is with the ordered logistic model. Here is my question: Generate an order discrete variable using the variable wrwage1 = wages in first full calendar quarter after benefit application in the following way: * wage*1*Ordered *= 1 *if*0 *· wrwage*1 *< *1000 2 *if*1000 *· wrwage*1 *< *2000 3 *if*2000 *· wrwage*1 *< *3000 4 *if*3000 *· wrwage*1 *<

Hello, I am working with zero inflated models for a current project and I am getting wildly different results from R's zeroinfl(y ~ x, dist="negbin") command and Stata's zinb command. Does anyone know why this may be? I find it odd considering that zeroinfl(y ~ x, dist="poisson") gives identical to output to Stata's zip function. Thanks, --david [[alternative

hello list! I'm sorry, I just stumbled over this strange behaviour (at least I am not able to explain the behaviour, therefore I assume it to be a strange behaviour): attach(water) # I know, this is not recommended names(water[3:10]) [1] "temp" "pH" "DO" "BOD" "COD" "no3" "no2" "po4" for (i in

Hello! I just joined this mailing list a couple of minutes ago. I'll start to use CentOS for academic purposes. We'll try to build a cluster based in machines with this OS. First of all, I'd like to beg you for patience, because I'm comple- tly new in Linux. My first question is: every tutorial on installation talks about inserting an installation CD, but I'm not sure about

Users report that an extent map''s list is still linked when it''s actually going to be freed from cache. The story is that a) when we''re going to drop an extent map and may split this large one into smaller ems, and if this large one is flagged as EXTENT_FLAG_LOGGING which means that it''s on the list to be logged, then the smaller ems split from it will also be

This request is related to the following post from last year: https://stat.ethz.ch/pipermail/r-help/2011-June/279752.html After reading the thread, the idea is still not clear. I have fitted a model using HURDLE from the PSCL package. I am trying to get marginal effects / slopes by multiplying the coefficients by the mean of the marginal effects (I think this is right). To my understanding, this

Is there a way to force certain formula parameters to be nonnegative? What I want to do is to estimate student capacity over time, namely by > capacity ~ Student + Student:Day I add this formula to a glm call and obtain negative learning slope estimates (Student:Day) in some cases. However, I don't want to allow for that. In such a case, glm should solve > capacity ~ Student and

Hello, I have the TCl/Tk command "tkmessageBox(titel="",message="x",icon="question",type="okcancel")" in my R script. Now I want to perform some operation in relation to the user's choice, something like "if (okpressed) xxx else yyy" What values does this command give and how are they used? Thank you, Richard -- Richard M?ller -

Hi Tim This is brilliant - thank you!! I've had to tweak the basePath line a bit (I am on a Linux machine), but having done that, the code works as intended. This is a truly helpful contribution that gives me ideas about how to work it through for the missing fields, which is one of the major sticking points I kept bumping up against. Thank you so much for this. All the best Andy On

Hello ; I am doing a regression of count data (number of award and there are some covariates) I have estiamted the parameters of negative binomial distribuion (lambda is a function of covaraites, GLM model) by glm.nb function and training dataset. Now I want to predict the number of award (for example y=0, y=1, y=2,) or testing dataset. I dont know how to calculate this numbers? I would be very