search for: ltraj

Hi. I am running the as.ltraj () function in adehabitat (v 1.4 under R 2.2.1) but can't seem to correctly specify the burst argument. i.e., the ltraj object returned consists of only one component, when in fact my data consist of more than one burst of reloctions per animal. i've set up the data (xy, date, id, burst) in...

Dear list, I just had a function (as.ltraj in Adehabitat) give me the following error: "Error in as.ltraj(xy, id, date = da) : non unique dates for a given burst" I checked my dates and got the following: > dupes<-mydata$DateTime[duplicated(mydata$DateTime)] > dupes [1] (07/30/02 00:00:00) (08/06/03 17:45:00) Is the...

...If I call "A1", I get a dataframe with columns "X1" and "Y1", so far so good. Now the trouble part: nam <- paste("test",1,sep="") for (i in 2:10) {nam[i] <- paste("test",i,sep="")} for (i in 1:10){assign(nam[i],as.ltraj(xy=char[1],date=DATE,...) ???????????? Please don't get carried away by as.ltraj, it's an object type of the package adehabitat to analyze animal tracks. However, I need to feed it the xy (coordination) information in form of a data frame. I have 20 animals to analyze (per different set...

I am trying to workout trajectories from GPS tracking data to run in the FPT function.    This is my code:   id<-data.frame (FPT[,6]) xy<-data.frame (FPT[,4], FPT[,3]) datet <- as.POSIXct (datetime) x<-as.traj(id, xy, datet)   And I get this error:   Error in sort.list(y) : 'x' must be atomic for 'sort.list' Have you called 'sort' on a list?   I have checked

Dear list, I have a table with entries for 20 animals - x and y coordinates to analyze movement with the package adehabitat. The package does all the necessary analyses, but I need to create an object of class ltraj for each animal first. For this kind of object I need to define xy coordinates, id, and few other things for each individual. Now I don't want to run a code 20 times but wanted to include for-loops to have it all run automatically on my entire table. First, create a vector with the vari...

...package for a description): (i) management of raster maps, (ii) habitat selection / ecological niche analysis, (iii) home range analysis, and (iv) analysis of animals trajects. The package contains several demo files to allow an overview of these parts : demo(rastermaps), demo(homerange), demo(managltraj), demo(analysisltraj), demo(nichehs). * the package now contains a new function allowing the exploration of the ecological niche, which generalizes several factor analyses (ENFA, MADIFA, ...) and is closely related to several methods (Mahalanobis distances, selection ratios, etc.), named gnesfa()...

...package for a description): (i) management of raster maps, (ii) habitat selection / ecological niche analysis, (iii) home range analysis, and (iv) analysis of animals trajects. The package contains several demo files to allow an overview of these parts : demo(rastermaps), demo(homerange), demo(managltraj), demo(analysisltraj), demo(nichehs). * the package now contains a new function allowing the exploration of the ecological niche, which generalizes several factor analyses (ENFA, MADIFA, ...) and is closely related to several methods (Mahalanobis distances, selection ratios, etc.), named gnesfa()...

...d at the coordinates, at the id, at the time of the run 43 and it's all good... I looked on the net and it happened to only one person and there was no answer to his post.  Someone could help me? ## commands BBtraj <- list() for (i in 1:(nrow(loc@data)-1)) { BBtraj[[i]] <- kernelbb(as.ltraj(loc@coords[i:(i+1),], date=loc@data$time[i:(i+1)], id = as.character(loc@data$id[i:(i+1)]), typeII = TRUE), sig1=as.numeric(as.character(loc@data$sig1[i])), sig2= 5, grid = 1000) }   Rémi Lesmerises, biol. M.Sc., Candidat Ph.D. en Biologie Université du Québec à Rimouski remilesmerises@yahoo.ca...

...time(as.character(mysample$Timestamp), "%d.%m.%Y %H:%M"), tz="GMT") mysamplexy <- project (cbind (mysample$Longitude, mysample$Latitude), "+proj=utm +zone=32 +ellps=WGS84") colnames(mysamplexy) <- c ("xCord", "yCord") ID <- mysample$ID datltraj <- as.ltraj(mysamplexy, mysampletime, id=ID) Ddat <- BRB.D(datltraj, Tmax=21600, Lmin=36) BRBdat <- BRB(datltraj, D= Ddat,type=c("UD"),Tmax=21600,Lmin=36, hmin=100) kernel.area(BRBdat, unout=c("km2")) # unfortunately my data are not a very good example. Sorry about tha...

...lsDataFrame. - the function clusthr and LoCoH return objects of class "MCHu", which are lists of SpatialPolygonsDataFrame - the function mcp returns a SpatialPolygonsDataFrame * home range estimation methods now take objects of class SpatialPoints as arguments * objects of class "ltraj" are now characterized by an additional attribute "infolocs", which is designed to store metadata on the trajectories (e.g. precision on the relocations). Most functions of the package adehabitatLT can be used to analyse these metadata (plotltr, etc. see the vignette). * the met...

...lsDataFrame. - the function clusthr and LoCoH return objects of class "MCHu", which are lists of SpatialPolygonsDataFrame - the function mcp returns a SpatialPolygonsDataFrame * home range estimation methods now take objects of class SpatialPoints as arguments * objects of class "ltraj" are now characterized by an additional attribute "infolocs", which is designed to store metadata on the trajectories (e.g. precision on the relocations). Most functions of the package adehabitatLT can be used to analyse these metadata (plotltr, etc. see the vignette). * the met...

...analysis of selection ratios (Calenge and Dufour, 2006, Ecology) can now be performed using the function eisera(). It can be used for the analysis of habitat selection when habitat can be considered to consist of several habitat types (e.g. vegetation types). - A new class, the class "ltraj", is now available for the analysis of trajectories of animals (e.g. for the analysis of data collected using GPS collars). This class automatically computes the turning angles between successive moves, the absolute angles for each move, the speeds and the net squared displacement for...

...analysis of selection ratios (Calenge and Dufour, 2006, Ecology) can now be performed using the function eisera(). It can be used for the analysis of habitat selection when habitat can be considered to consist of several habitat types (e.g. vegetation types). - A new class, the class "ltraj", is now available for the analysis of trajectories of animals (e.g. for the analysis of data collected using GPS collars). This class automatically computes the turning angles between successive moves, the absolute angles for each move, the speeds and the net squared displacement for...

...n? I'm not an expert and don't understand much of the technicalities mentioned in the Writing-R-extensions manual. I only would like to see how the method I think is used is actually implemented. I use R.2.13.1, Windows 7. The package I'm referring to is adehabitatLT, function acfang.ltraj -> res <- .C("acfangl",...) Many thanks in advance! Jacqueline [[alternative HTML version deleted]]

...) ] ) , "+proj=utm +zone=32 +ellps=WGS84" ) colnames( mysamplexy ) <- c( "xCord", "yCord" ) datltraj <- as.ltraj( mysamplexy, mysample$mysampletime, id=mysample$ID ) Ddat <- BRB.D( datltraj, Tmax=21600, Lmin=36 ) BRBdat <- BRB( datltraj, D = Ddat, type = "UD", Tmax = 21600, Lmin = 36, hmin = 100 ) result[ , i ] <- kernel.area( BRBdat, unout = "km2" ) } #&gt...

...problems. I don't know how to add columns to the lower levels of a list, or how to take something from the upper level and add it as a column to the lower level. I am analyzing animal movement data in the package Adehabitat. I have a list of animal movements called "cut.ltr" (class ltraj) that have been divided into a series of "burst" - i.e. movements with no gaps in time over a given threashold. I would like to 1. Add the speed to each item in the list, and also the burst. I can calculate speed as: sp<-lapply(cut.ltr,function(l){l$dist/l$dt}) This create...

...imestamp), > "%d.%m.%Y %H:%M"), tz="GMT") > mysamplexy <- project (cbind (mysample$Longitude, mysample$Latitude), > "+proj=utm +zone=32 +ellps=WGS84") > colnames(mysamplexy) <- c ("xCord", "yCord") > ID <- mysample$ID > datltraj <- as.ltraj(mysamplexy, mysampletime, id=ID) > Ddat <- BRB.D(datltraj, Tmax=21600, Lmin=36) > BRBdat <- BRB(datltraj, D= Ddat,type=c("UD"),Tmax=21600,Lmin=36, hmin=100) > kernel.area(BRBdat, unout=c("km2")) > > # unfortunately my data are not a very good...

Hey all, I've run into a few problems running first passage time analysis. I'm hoping someone might be able to help me sort this out. I'm fine up to the point of creating the ltraj object from a dataset. /test<-read.table("~/Desktop/R_Directory/test.txt",header=TRUE) attach(test) library(adehabitatLT) xy<-test[,c("x","y")] date1<-as.character(date) date<-as.POSIXct(date1) fit1<-as.ltraj(xy,date,id=test$name,burst=name,typeII=TRUE...

Hello, I tried to construct my very first loop today and completly failed :-( Maybe someone can help me? I have a dataframe somewhat like this one: myframe <- data.frame (Timestamp=c("24.09.2012 09:00", "24.09.2012 10:00", "24.09.2012 11:00", "25.09.2012 09:00", "25.09.2012 10:00", "25.09.2012

...lt;https://cran.r-project.org/web/packages/rpostgis/index.html>' package. rpostgisLT is aimed at those using R and/or the PostgreSQL/PostGIS database system to manage and analyze animal trajectory (movement) data. Package functions allow bi-directional transfer between the database and "ltraj" objects from the R package "adehabitatLT <https://cran.r-project.org/web/packages/adehabitatLT/index.html>", which has an extensive set of trajectory manipulation and analysis functions. To install the package: install.packages("rpostgisLT") To get started, please...