similar to: Selecting subsamples

Hi: I have data from an assay in the form of two vectors, one is response and the other is a predictor. When I attempt to fit a 5 parameter logistic model with "nls", I get converged parameter estimates. I also get the same answers with "gnls" without specifying the "weights" argument. However, when I attempt to use the "gnls" function and try to

Hi all; I?m working with the latest version of R under Win2000. My internet connection (using a proxy) requires my username and password. In this situation I?m not able to update the packages from CRAN (unless I download and install them from a local drive). I tried looking at information on the list servers but I couldn?t figure out how to change 'environment variables' or something like

Dear R-users Im working with a dataset that contains information for 8 groups of data and I need to select a sample of certain size (100 cubic feet by group) from this database for each of these 8 groups. To clarify, here is the starting code Im working with: k<-nrow(dataset) ix<-sort(runif(k),index.return=TRUE)$ix M<-max(which(cumsum(dataset$volume[ix])<100))+1

Back in 2005 I had been doing most of my work in Mathcad for over 10 years. For a number of reasons I decided to switch over to R. After much effort and help from you folks I am finally "thinking" in R rather than thinking in Mathcad and trying to translating to R. Anyway, the only task I still use Mathcad for is calculations that involve physical quantities and units. For example, in

Hola everyone, I'm doing an analisys about abundance of a planctonic specie in Robinson Crusoe Islan and I am having a hard time just adding the superscripts and the 100 (one hundred) in the measure of abundance. Perhaps this is so basic to you, but I need to put the real unit of measure. Individuals / 100 cubic meters. I have been looking in websites and R-list and there is not any

Hi all, I am working with a spatial data set for which I am only interested in high concentration values ("leaks"). The low values (< 90th percentile) have already been turned into NA's, leaving me with a matrix like this: < CH4_leak lon lat CH4 1 -71.11954 42.35068 2.595834 2 -71.11954 42.35068 2.595688 3 NA NA NA 4 NA

I have been using aggregate function to determine the annual minimum in a daily time series. However, I was also hoping to determine the date of occurrence without having to loop through each year to identify the date of each minimum returned from aggregate(). Is there a more convenient way of doing so? Thanks in advance, Dave library(zoo) n <- 1000 dly <- zoo( x = rnorm(n), order.by

Dear list members, I am facing some problems using the aggregate() function. I want to calculate a sum and a mean of one variable over the combination of 12 factors with the aggregate() function to avoid loops but it doesn't work (or the job is far too long, it exceeds 2 hours). It works with a fewer number of factors, so I constructed a factor being the levels combination of 7 factors (I

Hi R-helpers I'm looking for a vectorised function which does missing value replacement as in last observation carried forward in the zoo package but instead of a locf, I would like the locf function to add +1 to each time a missing value occurred. See below for an example. > require(zoo) > x <- 5:15 > x[4:7] <- NA > coredata(na.locf(zoo(x))) [1] 5 6 7 7 7 7 7 12 13

Sarah et. al.: As a matter of aesthetics (i.e. my personal ocd-ness) I prefer using the public API of an object, i.e. *not* to makes use of the representation of a factor as essentially an integer vector with labels, but rather to use its documented behavior. (Feel free to ignore this remark!) Anyway, >cumsum(!duplicated(dat1$B)) [1] 1 1 1 2 2 3 3 3 3 3 4 4 will do it. This is very

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I would like to read the following hierarchical data set. There is a family record followed by one or more personal records. If col. 7 is "1" it is a family record. If it is "2" it is a personal record. The family record is formatted as follows: col. 1-5 family id col. 7 "1" col. 9 dwelling type code The personal record is formatted as follows: col.

Dear all, I would like to randomly split a sample in two equally large subsamples. The sample data is stored as a matrix with each row representing an individual and each column representing some variable (e.g., name, age, sex, etc.); the first row contains the names of the variables; the first column contains the individual number (1:n, for n individuals); the number of individuals is even (so,

We (the lme4 authors) are having a problem with doing a proper deep copy of a reference class object in recent versions of R-devel with the LAZY_DUPLICATE_OK flag in src/main/bind.c enabled. Apologies in advance for any improper terminology. TL;DR Is there an elegant way to force non-lazy/deep copying in our case? Is anyone else using reference classes with a field that is an external pointer?

>From the documentation I have found, it seems that one of the functions from package plyr, or a combination of functions like split and lapply would allow me to have a really short R script to analyze all my data (I have reduced it to a couple hundred thousand records with about half a dozen records. I get the same result from ddply and split/lapply: >

Hi R-helpers, I have a dataframe with 60columns and I would like to convert several columns to factor, others to numeric, and yet others to dates. Rather than having 60 lines like this: data$Var1<-as.factor(data$Var1) I wonder if it's possible to write one line of code (per data type, e.g. factor) that would apply a function (e.g., as.factor) to several (non-contiguous) columns. So, I

Hi, Here's one way to approach it, using the coercion of factor to numeric. Note that I changed your data.frame() statement to avoid coercing strings to factors, just to make it simpler to set the levels. dat1 <-data.frame(N=seq(1, 12,1), B=c("29_log","29_log", "29_log", "27_cat", "27_cat", "1_log", "1_log",

Hello R-helpers! I have a question concerning extracting sequence information from a vector. I have a vector (representing the bins of a time series where the frequency of occurrences is greater than some threshold) where I would like to extract the min, median and max of each group of consecutive numbers. For Example: tmp <- c(24,25,29,35,36,37,38,39,40,41,42,43,44,45,46,47,68,69,70,71) I

Hi all: I've been looking at the boot package to "bootstrap" sample my data in a particular way. I haven't figured out how to set this up using the boot() command and thus have resorted to trying to write my own script (although I'd prefer if I could get boot() to work for this problem!) The dataset is set up in the following way: ix(factor) value 1 5.73 1 6.99 1

Hi All, I have a data frame dat1: dat1 <-data.frame(N=seq(1, 12,1), B=c("29_log","29_log", "29_log", "27_cat", "27_cat", "1_log", "1_log", "1_log", "1_log", "1_log",