search for: atyre2

Displaying 11 results from an estimated 11 matches for "atyre2".

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2007 Jun 15
2
converting character strings to numbers
...uot;,"",test)) # works Any suggestions? Or is this as good as it gets? I'm not complaining ... just curious! Drew Tyre School of Natural Resources University of Nebraska-Lincoln 416 Hardin Hall, East Campus Lincoln, NE 68583-0974 phone: +1 402 472 4054 fax: +1 402 472 2946 email: atyre2@unl.edu http://snr.unl.edu/tyre [[alternative HTML version deleted]]
2012 Mar 31
2
unable to move temporary installation
...es utils datasets methods base loaded via a namespace (and not attached): [1] tools_2.14.2 -- Drew Tyre School of Natural Resources University of Nebraska-Lincoln 416 Hardin Hall, East Campus 3310 Holdrege Street Lincoln, NE 68583-0974 phone: +1 402 472 4054 fax: +1 402 472 2946 email: atyre2@unl.edu http://snr.unl.edu/tyre http://aminpractice.blogspot.com http://www.flickr.com/photos/atiretoo [[alternative HTML version deleted]]
2012 Apr 03
0
Off Topic: Re: Calculating NOEL using R and logistic regression - Toxicology
...the NOEL is the > smallest dose above which there is a statistically significant effect. > This is not a scientifically meaningful nor defensible definition as it is stochastic, depends on the test used, design, level chosen, etc. -- Bert > On Tue, Apr 3, 2012 at 12:44 PM, Drew Tyre <atyre2 at unl.edu> wrote: > >> Is this the smallest observed dose that has an effect? If so, then you >> don't need the glm to find it. Here is a simulated example: >> >> set.seed(101) >> X = rep(1:10,each=10) >> lp = -5 + 0.5*X >> Y = rbinom(length(X),s...
2012 Apr 02
7
Calculating NOEL using R and logistic regression - Toxicology
Hello, I used the glm function in R to fit a dose-response relationship and then have been using dose.p to calculate the LC50, however I would like to calculate the NOEL (no observed effect level), ie the lowest dose above which responses start occurring. Does anyone know how to do this? [[alternative HTML version deleted]]
2012 Apr 10
1
Package boot, funtion cv.glm
Hey all, I need some help with a cross validation. I'm new with R and as well with statistics. I had a group work to create a tool for remote sensing class that extracts the best bands of hyperspectral satellite images that describe vegetation. Its a regression between a linear function of using a normalized differenced index (i-j)/(i+j) while i and j are the bands (in the data these are the
2012 Jun 25
1
using multiple cpu's - scaling in processing power
Hi All In the past I have worked with parallel processing in R where a function F is applied to the elements of a list L. The more cpu cores one has, the faster the process will run. At the time of launching the process for (F,L) I will have a certain fixed number of cpu's that I can use. I have tested this approach and it works fine (i.e. package 'multicore' , using 'mapply'
2012 Apr 05
1
reclaiming lost memory in R
Dear list, I am trying to reclaim what I think is lost memory in R, I have been using gc(), rm() and also using Rprof to figure out where all the memory is going but I might be missing something. I have the following situation basic loop which calls memoryHogFunction: for i in (1:N) { dataset <- generateDataset(i) fit <- try( memoryHogFunction(dataset, otherParameters)) } and
2012 Apr 10
2
Error: cannot allocate vector of size...
Hello: While running R doing the analysis of my data I (using packages such as BIOMOD or e1071) get the following error as a result of several of my analysis: Error: cannot allocate vector of size 998.5 Mb In addition: Warning messages: 1: In array(c(rep.int(c(1, numeric(n)), n - 1L), 1), d, dn) : Reached total allocation of 4095Mb: see help(memory.size) 2: In array(c(rep.int(c(1,
2012 Apr 03
5
R equivalent for SQL query
Hi, I have a query which I would like to translate into R, but I do not know how to do it in an easy way. Assume a data frame has columns A, B and C: A B C 1 1 3 1 1 4 1 1 5 1 2 6 1 2 7 1 3 8 The query is as follows: select A, B, count(*) from data.frame group by A, B order by count(*) desc How do I translate this into R statements in such way that the result is a data frame structured as
2012 Apr 10
5
Creating a loop with an indefinite end term
Everyone, I'm very new to R, especially when it comes to loops and functions, so please bear with me if this is an elementary question. I cannot seem to figure out how to construct a loop which runs a function until a certain value is computed. For example, say I have the following: num = numeric (10) num [1] = 0 for (i in 2:10) { num [i] = num [i-1] + 5 } This adds 5 to the
2012 Mar 25
2
avoiding for loops
I have data that looks like this: > df1 group id 1 red A 2 red B 3 red C 4 blue D 5 blue E 6 blue F I want a list of the groups containing vectors with the ids. I am avoiding subset(), as it is only recommended for interactive use. Here's what I have so far: df1 <- data.frame(group=c("red", "red", "red", "blue",