search for: mosnier

Hi all, I am quite new in the world of parallelization and I wonder if there is a way to increase the speed of creation of a parallel socket cluster. The time spend to include threads increase exponentially with the number of thread considered and I use of computer with two 8 cores CPU and thus showing a total of 32 threads in windows 7. Currently, I use the default parameters (type =

Dear R users, Since a long time now, I have the following error when I want to load the tcltk library in R 64 bit. Loading Tcl/Tk interface ...Error : .onLoad failed in loadNamespace() for 'tcltk', details: call: inDL(x, as.logical(local), as.logical(now), ...) error: unable to load shared object 'C:/Program Files/R/R-2.13.0/library/tcltk/libs/x64/tcltk.dll': LoadLibrary

Dear UseRs, Is there a way to define the lower-upper bounds for parameters fitted by optim using the Nelder-Mead method ? Thanks, Arnaud [[alternative HTML version deleted]]

Dear all, Since I installed the x64 version of R (v2.12.1), I got a problem with tcltk that I did not achieve to resolve. When loading the library, it gives me the following error message: Loading Tcl/Tk interface ...Error : .onLoad failed in loadNamespace() for 'tcltk', details: call: inDL(x, as.logical(local), as.logical(now), ...) error: unable to load shared object

Hi, In order to find the best models I use AIC, more specifically I calculate Akaike weights then Evidence Ratio (ER) and consider that models with a ER < 2 are equally likely. But the same problem remain each time I do that. I selected the best models from a set of them, but I don't know if those models are efficient to predict (or at least represent) my data. I can have selected the best

...I just want to know if I can use the AIC value given in the output of an lmer model to classify my logistic models. I heard that the AIC value given in GLIMMIX output (SAS) is false because it come from a calculation based on pseudo-likelyhood. Is it the same for lmer ??? thanks, Arnaud Arnaud MOSNIER Biologiste Ph.D. Département de Biologie Université du Québec à Rimouski 300 Allée des Ursulines Rimouski, Québec, G5L 3A1 Tél. : 723-1986 poste 1653 E-mail : arnaud_mosnier@uqar.qc.ca [[alternative HTML version deleted]]

Dear useRs, I try to import a text file that contain some strange characters coming from the misinterpretation of foreign language characters by another software (see below). ---------------------------------------- Here is an example of text with a line containing characters that bug the import name;number zdsfbg;2 ;3 dtryjh;4 ---------------------------------------- R do not want to import

Dear list, I fitted the same GAM model using directly the function gam(mgcv) ... then as a parameter of another function that capture the warnings messages (see below). In the first case, there is no warning message printed, but in the last one, the function find two warning messages stating "matrix not positive definite" So my question is: Do I have to worry about those warnings and

Dear useRs, In a thesis, I found a mention of the use of pairwise deletion in linear regression and GLM (binomial family). The author said that he has used R to do the statistics, but I did not find the option allowing pairwise deletion in both lm and glm functions. Is there somewhere a package allowing that ? Thanks, Arnaud [[alternative HTML version deleted]]

Dear Users, >From previous analysis (semi-variograms using package gstat), I found spatial autocorrelation in my dataset. The best fitted model to this spatial correlation structure is the Gaussian model (Spherical, Exponential, Linear tested and comparison done by Sum of Square errors). So I used corGaus function to define this spatial autocorrelation in my lme model using the option

Dears UseRs, In Zuur's book (Mixed effects models and extensions in ecology with R), p 167, it is mentionned that the Variogram function (package nlme) scale the sill to 1. Here is the plot of the semi-variogram given by the Variogram function on my "lme" object. (http://imm.io/3OLe) Note that the semi-variance exceed 1 !! It can probably explain why the Gaussian correlation

Dear list, Inspecting residuals of my linear models, I detected spatial autocorrelation. In order to take this into account, I decided to use the GLS method with the correlation = corGaus ( ~ X + Y). Then, I can sort my GLS models based on their AIC. But ... how to know the proportion of the variance explained by the best one (it can be best of the worst models) ? R-squared value has not the

Dear list, Here is a small example code that use optim and optimize in order to fit two functions. Is it possible to fit two functions (like those two for example) at the same time using optim ... or another function in R ? Thanks Arnaud ###################################################################### ## function 1 x1 <- 1:100 y1 <- 5.468 * x + 3 # + rnorm(100,0, 10) dfxy <-

Dear UseRs, I did not have any answer to my previous message ("Is there a way to define "manually" columns width when using write.dbf function from the library foreign ?"), so I tried to modify write.dbf function to do what I want. Here is my modified version : write.dbfMODIF <- function (dataframe, file, factor2char = TRUE, max_nchar = 254, width = d) {