similar to: two questions for R beginners

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

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')

"The R Inferno" is now on the Burns Statistics website at http://www.burns-stat.com/pages/Tutor/R_inferno.pdf Abstract: If you are using R and you think you're in hell, this is a map for you. Also, I've expanded the outline concerning R on the Burns Statistics 'Links' page. Suggestions (off-list) for additional items are encouraged. Patrick Burns patrick at

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

I'm interested in using a data frame as if it were a hash table. For instance if I had the following, > (d <- data.frame(key=seq(0.5, 3, 0.5), value=rnorm(6))) key value 1 0.5 -1.118665122 2 1.0 0.465122921 3 1.5 -0.529239211 4 2.0 -0.147324638 5 2.5 -1.531503795 6 3.0 -0.002720434 Then I'd like to be able to quickly retrieve the "value" of "key" 1.5

Is there a reason that 'which.min' and 'which.max' don't have an 'arr.ind' argument? The context in which I wanted that was a grid search optimization, which seems like it would be reasonably common to me. -- Patrick Burns pburns at pburns.seanet.com http://www.burns-stat.com (home of 'Some hints for the R beginner' and 'The R Inferno')

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

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]);

Pat Burns makes a good point. -Peter -------- Original Message -------- Subject: Re: [R] Using seq_len() vs 1:n Date: Fri, 12 Feb 2010 09:01:20 +0000 From: Patrick Burns <pburns at pburns.seanet.com> To: Peter Ehlers <ehlers at ucalgary.ca> References: <4B746AEF.10900 at ucalgary.ca> If you want your code to be compatible with S+, then 'seq_len' isn't going to work.

Hello, Does an e-learning environment for R (in English) exist? I would like to point out to students a way to learn R if they have missed the course on R. Pekka Pere University Lecturer University of Helsinki

There is a weakness in the 'sample' function that is highlighted in the help file. The 'x' argument can be either the vector from which to sample, or the maximum value of the sequence from which to sample. This can be ambiguous if the length of 'x' is one. I propose adding an argument that allows the user (programmer) to avoid that ambiguity: function (x, size, replace

Hello, I am working with a dataset with three variables and one binomial parameter. The glm function provides coefficients for these three variables, e.g. -1.5 | 27.2 | -2.9 If I'm not mistaken, $fitted.values gives me an estimate of how likely my parameter is to be true/1 . I would like to apply these coefficients on other variables to predict the binomial parameter but I'm not sure how

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 want to use order() to get the order of a vector. But I would need a different behavior when ties occur: similar to the parameter ties.method = "random" in the rank() function, I would need to randomise the ties. Is this possible? Example: x <- rep(1:10, 2) order(x) [1] 1 11 2 12 3 13 4 14 5 15 6 16 7 17 8 18 9 19 10 20 order(x) [1] 1 11 2 12 3 13 4 14 5 15

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)]

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 know that [] is used for indexing. I know that [[]] is used for reference to a property of a COM object. I cannot find any explanation of what [[1]] does or, more pertinently, where it should be used. Thank you. [[alternative HTML version deleted]]

It seems obvious to me that the empty string "" is length 0. cheers Worik [[alternative HTML version deleted]]