similar to: Calculating SD according to groups of rows

Hi, When I use logistic regression, each variable has a p value associated with it. Do I only include the variables that have a statistically significant p value (<0.05), or are there situations when I should include variables when their p values are high? I had heard that if a variable has a high p value but it's not the terminal variable, keep it; otherwise, take it out. Not sure if

Hi, Is there a way when doing logistic regression for the output to spit out accuracy, sensitivity, and specificity? I would like to know these basic measures for my model. Thanks! [[alternative HTML version deleted]]

Hi there, Just wondering if anyone has any tips for using arrays? I am trying to convert the following SAS code to R: data A2; set A1; by subject_id; retain BX1-BX10 i; array b(1:10) BX1-BX10 ; if first.subject_id then do ; do j=1 to 10; b(j) = .; end; i=1; end; b(i) = BX; i = i+1; if last.subject_id then

Hello everyone, I have a .csv file with the following format: uniqueID SubjectID Distance_miles Tag 1 1001 5.5 3 2 1001 7 1 3 1001 6.5 1 4 1001 5 1 5 1002

Hi there, I am interested in converting SAS code to R & I wondered if anyone had any quick R code/tips for the following piece of test SAS code? Any feedback greatly appreciated. data A1; set A1; count + 1; by subject_id; if first.subject_id then count = 1; run; [[alternative HTML version deleted]]

hi, I want to display a drop down list and when i select some option from the drop down list i want to display all the records under that selected category in the "SAME PAGE".. eg .. <%= collection_select(:question,:subject_id ,@subject, :id, :name) %> when i choose a subject i should, display all the questions under that subject in the same page.I am new to rails.Can

Dear R-help, I am creating a two lattice plots (a densityplot() and xyplot()) that have the same x-axes and then 'printing' them onto the same page, one above the other (see end of email for an example to generate the graph). With different labels on the y-axis for each plot the left spacing is different, and the x-axes don't align vertically. Although I can manually modify the

I am just assuming this can be done, but I have not gotten close to making it happen. I have a data file with about 1 million rows with 1470 unique subjects. Each row represents a small set of observations made on a specific date for a single subject. I would like to transform the data so that I have an R object with a single entry for each subject and start date and vectors for the

Hello to everybody, Does anyone has implemented a function for evaluating models using windowing strategies, such as growing window or sliding window ones? The aim is to evaluate regression models on a time series data. I do not use cross-validation once data sorted in a radom way does not make sense when evaluating time series. Thanks Joao Moreira

Estimadísimo Carlos: Muchísimas gracias por responderme y hacerlo tan rápido. Contemplé esa posibilidad, es decir, que el hiperparámetro estuviera suponiendo un problema, y probé de esta forma: > learner <- lrn("classif.ranger", num.trees = 5, mtry = NULL) Error: Element with key 'classif.ranger' not found in DictionaryLearner!

Hello all: I have a couple CentOS 4 servers (all up-to-date) that are having strange command failures. I first noticed this with a perl script that uses lots of system calls. Basically, sometimes a command just won't run: thoth(52) /tmp> ls thoth(53) /tmp> ls thoth(54) /tmp> ls thoth(55) /tmp> ls learner lost+found/ thoth(56) /tmp> ls learner lost+found/ thoth(57)

Dear R helpers, I created a somewhat big database (+206,700 rows) in MySQL and have exported into a csv file, but I can't open the whole thing in R. I am using: > base<-read.csv("/path/to/file.csv", header=F, sep="," nrows=206720) R doesn't complain but it only opens 128,328 observations (the number of columns corresponds to the original database): >

Hello, I'm attempting to evaluate the accuracy of the probability predictions for my model. As previously discussed here, the AUC is not a good measure as I'm not concerned with classification accuracy but probability accurcy. It was suggested to me that the loess function would be a good measure to look at. I can see some libraries (Design) will plot the loess function as a curve

Estimados amigos: Esta tarde he estado probando la librería mlr3, que me resulta muy interesante para trabajos de clasificación. En concreto, para entender su funcionamiento he probado un ejemplo simple (viene en CRAN). Sin embargo, cuando cambio el parámetro de clasifiación en la función de aprendizaje, me aparece el error siguiente: *Error: Element with key

DeaR ComRades, This is a quote from a News article in Science's 11-February issue, about competitions to model data: "For Chris Raimondi, a search-engine expert based in Baltimore, Maryland, and winner of the HIV-treatment competition, the Kaggle contest motivated him to hone his skills in a newly learned computer language called R, which he used to encode the winning data model.

I want to create a graph to express the idea of the area under a pdf curve, like http://r.789695.n4.nabble.com/file/n3032194/w7295e04.jpg Thank you for any help. ----- A R learner. -- View this message in context: http://r.789695.n4.nabble.com/How-to-plot-a-normal-distribution-curve-and-a-shaded-tail-with-alpha-tp3032194p3032194.html Sent from the R help mailing list archive at Nabble.com.

Hello, I have some trouble in achieving the desired parametrisation for the weka classifier functions, using the package RWeka. The problem is, that the functions result=classifier(formula, data, subset, na.action, control = Weka_control(mycontrol)) do not seem to be manipulated by the mycontrol- arguments Perhaps this should be resepected via the handlers- argument , but the

Dear list, I have a list, as follows : a <- 5 names(a) <- "a" b <- 9 names(b) <- "b" c <- 15 names(c) <- "c" x <- list("i" = a, "j" = b, "j" = c) I want to invert the list, like this : $a i 5 $b j k 9 15 I do not find a clean solution. Could anyone give me elegant ideas ? Thanks in advance, Carlos

Dear All, reposting, because I did not find a solution, maybe someone could check the example below. It's taken from the help page of survdiff. Executing it, gives the error "Error in floor(temp) : Non-numeric argument to mathematical function" best regards, Heinz library(survival) ## Example from help page of survdiff ## Expected survival for heart transplant patients based

I''m a slow learner when it come to shortcuts and i got real tired looking up Textmate''s Rails snippets & commands in the context menu. So i fired up trusty OmniGraffle and quickly created a little Cheat Sheet for all default snippets/macros/commands in Textmate''s current Rails Bundle. Certainly helped me to remember these quickly. So, if you''re