similar to: E-learning environment for R

I think the rule is that you can do anything as long as you don't complain. If you want to complain, you must follow the instructions. -- Jari Oksanen in Re: [Rd] Keeping up to date with R-devel -- Patrick Burns pburns at pburns.seanet.com twitter: @burnsstat @portfolioprobe http://www.portfolioprobe.com/blog http://www.burns-stat.com (home of: 'Impatient R' 'The R

I've just realized that it could be handy to have a 'decreasing' argument in 'is.unsorted'. And I'm cheekily hoping someone else will implement it. It is easy enough to work around (with 'rev'), but would be less hassle with an argument. The case I have in mind uses 'is.unsorted' in 'stopifnot'. Pat -- Patrick Burns pburns at pburns.seanet.com

Hi, I'm trying to set up R to run a simulation of two populations in which every 3.5 days, the initial value of one of the populations is reset to 1.5. I'm simulation an experiment we did in which we fed Daphnia populations twice a week with algae, so I want the initial value of the algal population to reset to 1.5 twice a week to simulate that feeding. I've use for loops and if/else

Hi, I want to calculate the Value at Risk with using some distirbutions and a volatility model. I use the following data(http://uploadeasy.net/upload/cdm3n.rar) which are losses (negative returns) of a company of approx. the last 10 years. So I want to calculated the Value at Risk, this is nothing else than the quantile. Since I have losses I consider the right tail of the distribution. Consider

Hi all, The subject line is TRUE. Today I accidentally typed rnorm(!0). My old eyes took a minute to focus clearly enough to see what I really typed and why I got '!0' random numbers instead of '10' random normal numbers. If the subject line is disturbing, be assured that this is TRUE: !0^2 == !0 * !0 # ;-) Anyway, I hope the hands who have been around long enough to know

Hi, I would like to cut a vector of values in parts. Each part should have an equal number of elements. for example: x <- (rnorm(500)^2) now I want 5 vectors each with 100 elements. The first vector should include the 100 lowest values of x and so on (so that the fifth vector contains the 100 highest values of x). thanks for any help!

Hi everyone, I'm using the following code to go over every element of a data frame (row wise). The problem I am facing is that the outer 'x' variable is not incrementing itself, thus, only one row of values is obtained, and the program does not proceed to the next row. This is the code: while(x<=coln) { while(y<=rown) { n<-as.numeric(df[[y]][x]);

Hello everyone, Considering the following code sample : ---- indexes <- function(vec) { vec <- which(vec==TRUE) return(vec) } mat <- matrix(FALSE, nrow=10, ncol=10) mat[1,3] <- mat[3,1] <- TRUE ---- Issuing apply(mat, 1, indexes) returns a 10-cell list, as expected. Now if I do: ---- mat[1,3] <- mat[3,1] <- FALSE apply(mat, 1, indexes) ---- I would expect a

Hey, I'm trying to implement a GARCH model with Johnson-Su innovations in order to simulate returns of financial asset. The model should look like this: r_t = alpha + lambda*sqrt(h_t) + sqrt(h_t)*epsilon_t h_t = alpha0 + alpha1*epsilon_(t-1)^2 + beta1 * h_(t-1). Alpha refers to a risk-free return, lambda to the risk-premium. I've implemented it like this: #specification of the model

I am trying to control the behavior of the SANN method in optim (R 2.14.1) via control$temp. In my toy tests it works; in my real use, it doesn't. As far as I can tell my code with different temp values is loaded; I even traced into the function that calls optim and verified temp had the value I had set. Could the fact that I have NaN's coming back from the objective function be a

I hope you are doing well. For me, this was an unexpected problem. I've hoped for quite a few wrong things today, but I'm only asking you about this one. Why does ifelse(1, list(a, b, c), list(x, y, z)) return a list with only a, not list(a, b, c) as I hoped. I wish it would either cause an error or return the whole list, not just the first thing. Working example: > x <- 1 >

Dear users, I'm trying to learn how to use the "...". I have written a function (simplified here) that uses doBy::summaryBy(): # 'dat' is a data.frame from which the aggregation is computed # 'vec_cat' is a integer vector defining which columns of the data.frame should be use on the right side of the formula # 'stat_fun' is the function that will be run to

Thanks. This is exactly the doubt I had. Rui Barradas ?s 05:26 de 05/08/2018, Kenny Bell escreveu: > This should more clearly illustrate the issue: > > c(1, 2, 3, 4)[-seq_len(4)] > #> numeric(0) > c(1, 2, 3, 4)[-seq_len(3)] > #> [1] 4 > c(1, 2, 3, 4)[-seq_len(2)] > #> [1] 3 4 > c(1, 2, 3, 4)[-seq_len(1)] > #> [1] 2 3 4 > c(1, 2, 3, 4)[-seq_len(0)]

Hi, What is quickest way to learn R? I am unnecessarily having fear of learning R. rgds Parag Kulkarni Haridwar,India -- View this message in context: http://r.789695.n4.nabble.com/R-learning-tp4631814.html Sent from the R help mailing list archive at Nabble.com.

R-help is all about solving R problems. So here ya go: http://www.portfolioprobe.com/2011/09/12/solve-your-r-problems/ -- Patrick Burns pburns at pburns.seanet.com twitter: @portfolioprobe http://www.portfolioprobe.com/blog http://www.burns-stat.com (home of 'Some hints for the R beginner' and 'The R Inferno')

There is something that I wish I had that I think would help me a lot to be a better R programmer, that I think would probably help many others as well. I put the wish out there in the hopes that someone might think it was worth doing at some point. I wish I had the code of some substantial, widely used package ? lm, say ? heavily annotated and explained at roughly the level of R knowledge of

Hello! I am optimizing my code in R and for this I need to know a bit more about the internals. It would help tremendously if someone could link me to a page with O()-complexities of all the operations. In this particular case, I need something like a linked list with O(1) insertLast/First ability. I can't preallocate a vector since I do not know the final size of the list ahead of time. The

Dear R forum helpers,I have following datatrans <- data.frame(currency_transacted = c("EURO", "USD", "USD", "GBP", "USD", "AUD"), position_amt = c(10000, 25000, 20000, 15000, 22000, 30000))date <- c("12/31/2010", "12/30/2010", "12/29/2010", "12/28/2010", "12/27/2010",

Hi, I have limited experience on R and recently started using REXcel. Although I have been able to run both simple functions (like mean etc) and some complex ones (like Principal Component analysis, PCA) using RExcel, I am facing some problems while running EGARCH model. For this I have downloaded the 'betategarch' package for R to run EGARCH with student t dist. Although the package has

Hello, I'm very interested in using financial time series data, but I'm a beginner of R programming. I'd like to fully understand internal logics on several time-series related packages such as quantmod, xts, zoo, chron, etc. So, I read some books, 'R Cookbook' and 'Art of R Programming' and another simple tutorials. But I still can't understand grammars of the