similar to: Measuring the change in coupling of time series through time.

Dear R users I have built the following model m1<-lmer(y~harn+foodn+(1|ass%in%pop%in%fam),family = "quasibinomial") where y<-cbind(alive,dead) where harn and foodn are categorical factors and the random effect is a nested term to represent experimental structure e.g. Day/Block/Replicate ass= 5 level factor, pop= 2 populations per treatment factor in each assay, 7 reps

Dear R users I have built several glmm models using glmmPQL in the following structure: m1<-glmmPQL(dev~env*har*treat+dens, random = ~1|pop/rep, family = Gamma) (full script below, data attached) I have tried all the methods I can find to obtain some sort of model fit score or to compare between models using following the deletion of terms (i.e. AIC, logLik, anova.lme(m1,m2)), but I

Hi, I have data on stomach contents. Possible prey species are in the hundreds, so a list of prey codes has been in used in many labs doing this kind of work. When comes time to do analyses on these data one often wants to regroup prey in broader categories, especially for rare prey. In SAS you can nest a large number of "if-else", or do this more cleanly with "select"

I have installed Prey onto my pc running PCLinuxOS following the instructions in http://frankscorner.org/index.php?p=prey or http://appdb.winehq.org/objectManager.php?sClass=application&iId=3465 and tried running it. I then found I needed the nocd patch, which I downloaded and applied. I then tried cd to the app folder, then wine prey.exe with the following result: Prey 1.0.103 win-x86 Jun 10

Hi, I'm trying to move to R the last few data handling routines I was performing in SAS. I'm working on stomach content data. In the simplified example I provide below, there are variables describing the origin of each prey item (nbpc is a ship number, each ship may have been used on different trips, each trip has stations, and individual fish (tagno) can be caught at each

Hello, I have a syntactic problem with ode. How do I specify vectors of equations in ordinary differential equation systems. (i.e. in my case I want to simulate an a priory undefined number of species that have different parameters but the same behaviour) I demonstrate this using the Lotka Volterra example. The code below does not work and I have not a good idea how to specify this right. ##

Hi R experts :) I'm trying to carry out a survival model on my data, but I am unsure of whether it's appropriate or if I should do something specific in regards to hazard. My data is time to death by predator where I have 8 prey and one predator in the setting. This means that two prey can't possibly die at the same time and I can't quite get my head around how to include this in

Hi, I wonder if anyone can help me with specifying a right model for my analysis. I am a beginner to lme methods and though have spent already many hours studying from various books an on-line helps, I was unfortunately not able to find a solution to my problem on my own. Data structure: I studied escape behavior of three species of a prey to a predator. The prey specimens (many) were in a

As will be seen from these code fragments (and experiment) a noclobber option in bash or pdksh (or ksh on AIX) will do limited clobbers. 1) They will clobber named pipes. (mknod /tmp/predicted p cat /tmp/predicted > $stolen cat $switched > /tmp/predicted ) & 2) They will clobber symlinks. ln -s /some/new/target /tmp/predicted 3) They can be raced.

Dear R-users, I am currently modifying a previously developed predator prey model and was curious if there was a way to add in a disturbance to the model (let's say at time t=100). The disturbance can be the introduction of 40 prey (N=40) and 10 predators (Pred = 10). I would like to see my model go from a state of equilibrium (up to t = 99), show this disturbance (at t = 100) and then

Hello again. Since my last post about giving up on Prey I have had to change my graphics card. The cooling fan on my ATI packed up and it was a choice of a new fan/heatsink combination and having to nearly rebuild my pc to allow room for it (nearly the size of my card and over 1 inch thick !) or replacing the card. Since I thought that the fan problem might be the thin end of the wedge and I might

Dear all, I studied in tank prey fish behavior. Using the design described below (and R code), I want to test the effects of both habitat and predator (and interaction) on prey fish's vertical distribution, which was recorded (with repeated measures) as a categorical variable. I found that package mlogit might fit to my need but I don't know how to specify my complex design in the

Dear R friends- I'm attempting to generate a regression tree with one gradient predictor and multiple responses, trying to test if change in size (turtle.data$Clength) acts as a single predictor of ten multiple diet taxa abundances (prey.data) Neither rpart or mvpart seem to allow me to do multiple responses. (Or if they can, I'm not using the functions properly.) > library(rpart)

Hi I am struggling with the correct code syntax to generate xyplots that are different from the default graphics option. This is simplified version of my data: site size dnaconc prey A 44 22.6 1 A 47 18.2 1 B 38 25.6 0 B 47 20.5 1 C 45 30.5 0 C 32 18.5 0 D 45 15.0 1 D 22 20.1 0 So I am using xyplot(dnaconc~size|site,data=bug,groups=prey) to generate 4 panels (one for each site). My

Dear list, I´m using the mgcv package to model the proportion by weight of certain prey on the stomach content of a predator. This proportion is the ratio of two weights (prey weight over stomach weight), and ranges between 0 and 1. The variance is low when proportion is close to 0 and 1, and higher at intermediate values. It seems that the best way to go is to model this using the

Is there any R package that can help me with digging out the maxima of a 1-D trajectory ? I have 975 1-D curves. They are only known as time series. That is a set of points ordered with respect to time. Some curves exhibit one only peak. Others have two peaks of different height. We wish to find the number of peaks and their position along the time axis. Apparently it's a trivial problem

Hello, I am trying to model a type II functional response of number of prey eaten (Ne) against number supplied (No) with a non-linear least squares regression (nls). I am using a modification of Holling's (1959) disc equation to account for non-replacement of prey; Ne=No{1-exp[a(bNe-T)]} where a is the attack rate, b is the handling time, and T is the experimental period. My script is as

I'm fairly new to R, and I'm trying to write out a population model that satisfies the following; the system consists of s species, i= 1, 2,...,s network of interactions between species is specified by a (s x s) real matrix, C[i,j] x[i] being the relative population of the "ith" species (0 =< x[i] =< 1, sum(x[i]=1) the evolution rule being considered is as follows;

*Thanks* all those who took the time to help me (even if the "question" was not related to - the use of - R). Now I think I can soundly make my point w/ the referee (can I use your replies? If so I intend to properly cite its use?!?). Regards, Eduardo Esteves ps - Sorry for not explaining the "biological details" of my posting: RNA/DNA is the ratio of RNA content to

Greetings I'm using R 2.8 with recent (last month) versions of the packages I need to use at present. I'm interested in examining hierarchical spatio-temporal patterns in a data set. The data consist of 94 points (X, Y, UTM coordinates) at which catch rates for a fish were recorded and there are also estimates of prey available for these fish at the same locations.