similar to: anova on binomial LMER objects

Displaying 20 results from an estimated 100 matches similar to: "anova on binomial LMER objects"

2006 Feb 09
1
glmm.admb - bug and possible solution??
Dear Dr Skaug and R users, just discovered glmm.admb in R, and it seems a very useful tool. However, I ran into a problem when I compare two models: m1<-glmm.admb(survival~light*species*damage, random=~1, group="table", data=bm, family="binomial", link="logit") m1.1<-glmm.admb(survival~(light+species+damage)^2, random=~1, group="table", data=bm,
2006 Sep 12
1
Using XY location data to calculate ecological parameters
Dear R gurus, I have XY data giving the locations of tree seedlings that were surveyed during a 210 meter belt transect. This belt transect was taken by stretching a line across the field, then measuring all seedlings within 1 meter on either side of the line. The end result was XY coordinates and height for ~1,300 seedlings. I would like to use that data to calculate density of
2003 Nov 04
1
glm offset and interaction bugs (PR#4941)
Full_Name: Charles J. Geyer Version: 1.8.0 OS: i686-pc-linux-gnu (Suse 8.2) Submission from: (NULL) (134.84.86.22) Two bugs (perhaps related, perhaps independent) revealed by the same Poisson regression with offset mydata <- read.table(url("http://www.stat.umn.edu/geyer/5931/mle/seeds.txt")) out.fubar <- glm(seedlings ~ burn01 + vegtype * burn02 + offset(log(totalseeds)),
2006 Apr 23
1
Comparing GLMMs and GLMs with quasi-binomial errors?
Dear All, I am analysing a dataset on levels of herbivory in seedlings in an experimental setup in a rainforest. I have seven classes/categories of seedling damage/herbivory that I want to analyse, modelling each separately. There are twenty maternal trees, with eight groups of seedlings around each. Each tree has a TreeID, which I use as the random effect (blocking factor). There are two
2009 Aug 31
2
interactions and stall or memory shortage
Hello, After putting together interaction code that worked for a single pair of interactions, when I try to evaluate two pairs of interactions( flowers*gopher, flowers*rockiness) my computer runs out of memory, and the larger desktop I use just doesn't go anywhere after about 20 minutes. Is it really that big a calculation? to start: mle2(minuslogl = Lily_sum$seedlings ~ dnbinom(mu = a,
2008 May 15
2
mixed effects models with nested factors
Hi everybody, I am trying to fit a model with the lmer function for mixed effects. I have an experimental design consisting of 5 field plots. Each plot is divided in 12 subplots where the influence of three factors on the growing of tree seedlings is tested: (1) seed (1 = presence; 0 = absence); (2) seedling species (oak holm vs. pine); (3) treatment (three different treatments). In each of
2011 Jun 28
2
coxph() - unexpected result using Crawley's seedlings data (The R Book)
Hi, I ran the example on pp. 799-800 from Machael Crawley's "The R Book" using package survival v. 2.36-5, R 2.13.0 and RStudio 0.94.83. The model is a Cox's Proportional Hazards model. The result was quite different compared to the R Book. I have compared my code to the code in the book but can not find any differences in the function call. My results are attached as well as a
2009 Aug 28
1
Help with glmer {lme4) function: how to return F or t statistics instead of z statistics.
Hi, I'm new to R and GLMMs, and I've been unable to find the answers to my questions by trawling through the R help archives. I'm hoping someone here can help me. I'm running an analysis on Seedling survival (count data=Poisson distribution) on restoration sites, and my main interest is in determining whether the Nutrients (N) and water absorbing polymer Gel (G) additions to the
2005 Jul 19
2
Regression lines for differently-sized groups on the same plot
Hi there, I've looked through the very helpful advice about adding fitted lines to plots in the r-help archive, and can't find a post where someone has offered a solution for my specific problem. I need to plot logistic regression fits from three differently-sized data subsets on a plot of the entire dataset. A description and code are below: I have an unbalanced dataset
2011 Apr 10
1
survival object
Hi All, I am trying to do a survivorship analysis with library(survival)from a data set that looks like this: I followed a bunch of naturally germinated seedlings of an annual plant from germination to death (none made it to reproduce, and died in a period of ~60 days after germination.) I also know the size of the seed of every individual censused. So I am trying to analyze seedling survival as
1999 Sep 27
0
HTML Output from R
Apologies to the group for not having summarized (and taking all this time) all the replies I got on this topic. The original question was if anyone had done HTML output from R. The message also included a first attempt at writing such a function.. _________ Thanks, to Terry Westley who suggested that I model the function after write.table. I was not aware of write.table (my fault). Since then I
2009 Sep 26
1
Multiple comparisons for coxph survival analysis model
Hello, all R-users! I am working on fitting a survival analysis model using the coxph function for Cox proportional hazards regression model. Data look like usual: ========================== group block death censor Group1 1 4 1 Group1 1 12 1 ... Group2 30 4 1 Group2 30 4 1 ... Group3 57 16
2010 Apr 20
1
multiple plots problem
hello, i try to plot 3 graphs which have the same x.axis underneath each other. i'd like the plots to be aligned without margings between the boxes and draw a single x axis beneath the lowest plot. i managed to get the alignment by setting par(mar), but the middle box is stretched and i cant't figure out how to get around this. par(pin) was my guess, but this doesn't do the job
2013 Oct 03
2
SSweibull() : problems with step factor and singular gradient
SSweibull() :  problems with step factor and singular gradient Hello I am working with growth data of ~4000 tree seedlings and trying to fit non-linear Weibull growth curves through the data of each plant. Since they differ a lot in their shape, initial parameters cannot be set for all plants. That’s why I use the self-starting function SSweibull(). However, I often got two error messages:
2009 Aug 28
0
Help with glmer {lme4} function: how to return F or t statistics instead of z statistics?
Hi, I'm new to R and GLMMs, and I've been unable to find the answers to my questions by trawling through the R help archives. I'm hoping someone here can help me. I'm running an analysis on Seedling survival (count data=Poisson distribution) on restoration sites, and my main interest is in determining whether the Nutrients (N) and water absorbing polymer Gel (G) additions to the
2009 Oct 05
1
interpreting glmer results
Hi all, I am trying to run a glm with mixed effects. My response variable is number of seedlings emerging; my fixed effects are the tree species and distance from the tree (in two classes - near and far).; my random effect is the individual tree itself (here called Plot). The command I've used is: mod <- glmer(number ~ Species + distance + offset(area) + (1|Plot), family = poisson)
2012 Jul 31
0
Arrangement of names
Dear R-help members I would be grateful if anyone could help me with the following problem: 1: I changed the font style of the plant names (along x-axis, under the bars) to "italic" . How can I avoid that the font in the legend also changes to "italic"? 2. I would like to place the plant names (along x-axis, under the bars) in a way that : a) the first plant name is under the
1999 Feb 12
1
Fisher's Exact Test
Appology in advance if this has been asked and answered. I am getting different answers using Fisher's exact test in the package ctest. For example: x_cbind(c(8, 22), c(31, 29)) fisher.test(x) Fisher's Exact Test for Count Data data: x p-value = 0.04024 alternative hypothesis: two.sided However, in SAS or other packages on the net the answer I get is p-value= 0.02664. Is this
2008 Feb 22
3
projection.matrix() {popbio} for more than one matrix
Hello, I am trying to use the projection.matrix( ) function and am following the example given. I have my data formatted very similar to the test.census example. > str(AsMi05mat) `data.frame': 1854 obs. of 6 variables: $ Tag : num 501 502 503 504 505 506 507 508 509 510 ... $ Year : int 1995 1995 1995 1995 1995 1995 1995 1995 1995 1995 ... $ Length : num 34
2009 Nov 13
0
z-test with NAs
Dear all I am learning R I am doing Z-test with package 'BSDA' here is my syntax and result: > sdgr.ztest<-z.test(growth[type=='SD'& from_treeline=='above'], + growth[type=='SD'& from_treeline=='below'],alternative = "two.sided", + mu = 0, sigma.x =(sd(growth[type=='SD'& from_treeline=='above'],na.rm = T)), +