search for: juliane_struve

...or all trips in "trips" ??? ? Many thanks for any suggestions. ? ? Juliane ? ? ? ? ? ? ?Dr. Juliane Struve Environmental Scientist 10, Lynwood Crescent Sunningdale SL5 0BL 01344 620811 ----- Original Message ---- From: jim holtman <jholtman at gmail.com> To: Juliane Struve <juliane_struve at yahoo.co.uk> Cc: r-help at r-project.org Sent: Friday, 18 September, 2009 15:02:47 Subject: Re: [R] matching pairs regardless of order Here is an example: > x <- c('loc1,loc2', 'loc2,loc3', 'loc2,loc1', 'loc3,loc1') > x.s <- strsplit(x, ','...

Dear list, ? I am using match() to match pairs of locations, e.g. trip="loc1,loc2" from a list of such pairs, e.g. list=("loc1,loc2", "loc1,loc3", "loc2,loc3","loc2,loc1"). ? In this example match() will match "trip" with the first element of "list", but not the 4th, because the order is reversed. ? How can I get a match with

Dear list,   Dear list, I am using read.csv.sql() from the sqldf package to read individual-based data from a csv file that is too large for R. My original file contains a column called “ID” that identifies the individual. I would like to read in data for only one individual at a time, for example "Bobby". read.csv.sql("filename",sql = 'select * from file where ID =

Dear list, ? I would like to plot several age distributions that are influenced by a factor (called group in the data example below). I would like to use historam() in the lattice package, but I can't figure out how to set up the data. Could someone give me a hint how to do it? for the example below? ? Thanks a lot, ? Juliane? ? data <- structure(list(Age = c(1L, 1L, 1L, 2L, 2L, 2L, 3L,

Dear list, ? I am intersted in estimating movement based kernel densities for fish that were relocated at fixed receivers positioned along the coast. These data tend to display both a drift movment between receivers and a random movement component that can be estimated from the mean and the variance of the transit time between receivers. ?If I obtain an estimate of the diffusion coefficient from

Dear list,   I am looking for an R-only implementation of a Nelder-Mead process that can find local maxima of a spatially distributed variable, e.g. height, on a spatial grid, and outputs the coordinates of the new point during each evaluation. I have found two previous threads about this topic, and was wondering if something similar has been implemented since those messages were posted.   Thank

Dear list, ? would anybody be able to tell me why the statement ? Tripstatistics=aggregate(TripsData[2:3],by=list(Trip=Tripmatch),FUN="mean") ? seems to work well with TripsData 1 but not with TripsData 2 ? ? With TripsData 2 it yields ? Error in FUN(X[[1L]], ...) : arguments must have same length I can't see a difference in the two data sets. Could someone shed light on the error

Dear members, How can I read and plot an ArcGIS raster file into R ? The file has extension .aux and contains floating point bathymetry data. The purpose is to create a spatial model in R that uses ArcGIS map data. I have managed to read and plot various shape files into my R project, but I am stuck with this now. I am new to this list and also to R, so any help would be much appreciated. Many

Dear list, ? I am trying to program semi-random movement within a circle, with no particles leaving the circle. I would like them to bounce back when they come to close to the wall, but?I don't seem to be able to get this right. ?Would somebody?be able to?give me a hint ? This is my code so far, the particle starts at some point and moves towards the wall, but I don't get the