similar to: finding an unknown distribution

Hi, I am performing a repeated measures 2-way ANOVA to assess the influence of plant and leaf on aphid fecundity. Fecundity is measured for each aphid on a single leaf. Here is what I typed. wingless <- reshape(Wingless, varying =

Hello, I'm trying to use the groupedData function and R is giving me the message: Error: can not find function "groupedData" The code is coming from a textbook so I think it should be correct: pigs<-data.frame(cbind(pig.time,pig.id,pig.wt)) pig.growth<-groupedData(pig.wt~pig.time|pig.id,data=pigs) I have added the package "nlme" and to confirm that it was installed

e1 <- function(x,b,t){ d<-(x)*(b^t) plot(d) } e1(2, 2,seq(from=0, to=6, by=1)) Is there a way to do this with a change in time. I would like to use differential equations. I am trying to model a population with an initial value, fecundity per time step, and a death rate. The above simply shows an exponential growth rate. I would like to model species response like the famous

hello everyone, I would like to as for advice for the use of ?lmer? (package ?lme4?) and writing the proper syntax to best describe my data using a mixed-effects model. I have just started to use these models, and although I have read some good examples (Extending the Linear Model with R, Faraway 2005; and the R book, Crawley 2007), I am still not sure of the syntax to test my hypothesis.

I write about R every weekday at the Revolutions blog: http://blog.revolutionanalytics.com and every month I post a summary of articles from the previous month of particular interest to readers of r-help. In case you missed them, here are some articles related to R from the month of June: The FDA goes on the record that it's OK to use R for drug trials: http://bit.ly/M0OoqA A review of

Hola, Estoy tratando de calcular el poder estadistico de un GLM en R, programas estadisticos como SPSS lo puede calcular pero no eh encotrado nada sobre R. Alguien tiene alguna idea o sabe de literatura donde pueda encontrar ayuda? Luego tengo otra pregunta mas bien teorica sobre la funcion offset utilizada en negative poisson, por lo que eh entendido esta funcion posibilita trabajar con

Hey, So I have a scatter plot and I am trying to plot a curve to fit the data based on a Holling Type III functional response. My function is this: nll2<-function(a,b) { conefun<-(a*DBH^2)/(b^2+DBH^2) nlls2<-dnbinom(x=cones ,size=DBH, mu=conefun,log=TRUE) -sum(nlls) } and my plot is this: plot (DBH,cones) DBH is on the x-axis and cones is on the y-axis. How do I get the curve

Hi, I'm programming in R and below is a summary of a generalized linear model: ************************************************** *** Call: glm(formula = offspring ~ degdays, family = quasi(link = "log", variance = "mu"), data = fecundity) Deviance Residuals: Min 1Q Median 3Q Max -0.76674 -0.29117 -0.09664 0.15668 1.00800 Coefficients: Estimate Std. Error t value

Dear R-help list, I have a problem storing results from a bootstrap loop. What I doing is creating an empty matrix before the loop, then run the loop. Before the end of the loop I have a command line which defines which results inside the loop will have to go in the empty matrix. Here is the code I am using: eigen.values<-rep(NA,boots) #storage file for eigen values (1 for simulation)

Dear Ben, you answerd to Nancy Shackelford about Clarks 2Dt function. Since the thread ended just after your reply, I would like to ask, if you have an idea how to use this function in R I defined it the following way: function(x , p, u) { (p/(pi*u))*(1+(x^2/u))^(p+1) } and would like to fit this one to my obeservational data (count) [,1] [,2] [1,] 15 12 [2,] 45 13 [3,]

Estimado Matias, Reenvio a la lista. Es tarde aqui y hay que descansar. Quizas alguien en otra parte del mundo pueda darte una mano. En unas horas te envio mi opinion. Saludos, Jorge.- 2013/6/11 Matias Ledesma <> > Hola Jorge, > > Muchas gracias por las referencias, ya consegui el libro asi que me voy > aponer a leerlo aver si encuentro una solucion. > > La data

I'm trying to use nls() to fit an exponential decay with an unknown offset in the time (independent variable). (Perhaps this is inherently very difficult?). > decay.pl <- nls (amp ~ expn(b0,b1,tau,t0,t), data = decay, + start = c(b0=1, b1=7.5, tau=3.5, t0=0.1), trace=T) Error in nlsModel(formula, mf, start) : singular gradient matrix at initial parameter estimates

Hello, I am trying to create multiple matrices (to run a PVA) but can't import all of them from a .csv without the numbers treated as labels and not factors. I can enter the matrix slowly: Site05_96 <- matrix(c(0.07,0,0.03,0.00,NA,0.00, 0.09,0.166666667,0.31,0.42,NA,0.00, 0.00,0,0.00,0.00,NA,0.00, 0.00,0,0.00,0.00,NA,0.00,

Hello I'm a population ecologist and use R for all my stats and modelling. Recently I have been using R to numerically solve integral projection models. This involves constructing several large matrices. The current code by Easterling (Size-specific sensitivity: Applying a new structured population model. Ecology, 2000, 81, 694-708) uses nested loops to construct the matrices. To speed up the

Estimado Javier, Gracias por tus comentarios. Si, puede ser que me haya expresado en forma incorrecta. Mi idea fue tratar de ser lo mas conciso posible y limitarme al problema estadistico que tengo, por lo cual obvie mucha informacion. La data proviene de un monitoreo que se hace en el Mar Baltico anulamente hace mas de 20 años, debido a que la poblacion a decendido drasticamente en los

Dear All, I hope the title speaks by itself. I believe that there should be a solution when I see what Mclust is able to do. However, this problem is quite particular in that d3 is not known and does not necessarily correspond to a common distribution (e.g. normal, exponential ...). However it must look like dmix and d1 to some extent. To illustrate my problem I worked out a simple example:

Dear R-users, Attach with is my data..what i want to do is finding a suitable distribution for my data..I want to run a few test like the poisson and the exponential distribution. Please help me on how to find the p-value for poisson as well as the exponential distribution without knowing the parameter. Is it possible?? Thanks in advance. love, Anisah -------------- next

Dear all, I have a set of x,y,z points obtained from a lizard species and now I would like to estimate the three-dimensional use of space for this species. I know that 2D area I can estimate using adehabitat packages, but I don´t know how to estimate the volumetric space. Any help are welcome. Miltinho Brazil [[alternative HTML version deleted]]

Hi all, I am attempting to fit, and test the goodness of fit of, a mixed exponential distribution to my dataset which consists of 15minute rainfall intensity data. FYI, the dataset spanning approx.2 years and 7 rainfall stations consists of some three hundred thousand 15min data records, of which some 30 thousand are non-zero rainfall amounts. Could anyone please tell me how i could do

Hi, I'm trying to use ad.test or ad2.test to test whether a given data set is exponential. I see that one of the function inputs is "distn", but I try "exponential" and 5 other variants, but I still get the error message: ad.test(test2, distn="exponential", fit=list(estimate = 0.167685), H=NA, sim=100) Error in ad.test(test2, distn = "exponential",