similar to: inherits() and virtual classes

Hi it says in R-exts that A method must have all the arguments of the generic, including ... if the generic does. A method must have arguments in exactly the same order as the generic. A method should use the same defaults as the generic. So, how come the arguments for rep() are (x, times, ...) and the arguments for rep.default() are (x, times, length.out, each, ...) ?

Hi I thought it would be fun to develop R functionality for the octonions (there is already some work on quaternions). The octonions are an 8 dimensional algebra over the reals, so an octonion may nicely be represented as a real vector of length 8. Applications are many and varied, mostly quantum mechanics. I would like to develop some R functionality in this area. My first problem is how

Hi how do I extract those components of a list that satisfy a certain requirement? If jj <- list(list(a=1,b=4:7),list(a=5,b=3:6),list(a=10,b=4:5)) I want just the components of jj that have b[1] ==4 which in this case would be the first and third of jj, viz list (jj[[1]],jj[[3]]). How to do this efficiently? My only idea was to loop through jj, and set unwanted components to NULL,

Hi In NEWS, it says R CMD check now tests that the package can be loaded, and that the package and namespace (if there is one) can each be loaded in startup code (before the standard packages are loaded). For package "onion", I think I have followed all of sections 1.6.1 - 1.6.6 of R-exts, and it passes R CMD check for R-2.3.1. However, using R version 2.4.0 Under

Hi I have written a whole bunch of methods for objects of class "octonion". [ an octonion is a single column of an eight-row matrix. Octonions have their own multiplication rules and are a generalization of quaternions, which are columns of a four-row matrix. ] So far I've done about a dozen generic functions such as seq.octonion(), rep.octonion(), [<-.octonion(), and so on

Hi section 6.1 of R-exts suggests that a package can take over a function in the base package and make it generic. I want to do this with Re() and have the following lines in my R code: "Re" <- function(x){UseMethod("Re" )} "Re.default" <- get("Re" ,pos=NULL,mode="function") "Re.octonion" <- function(x){give.comp(x,1)}

Hi again everyone I have an arbitrarily dimensional array "a" and a list "jj" of length length(dim(a)). The elements of jj are vectors of indexes. How do I use do.call() to extract a[ jj[[1]], jj[[2]], jj[[3]], ...] ? Toy example follows: a <- matrix(1:30,5,6) jj <- list(5:1,6:1) I want the following a[ jj[[1]],jj[[2]] ] How do I do this? OBAttempts:

Hello everyone I am trying to get one of my packages through R's QC. The package is clean for me under R-2.4.1, R-2.5.0, and R-devel, but Kurt gets > > * checking R code for possible problems ... WARNING > hypercube: no visible binding for global variable ?f? Function hypercube() [cut-&-pasted below] is intended to return an adjacency matrix for an n-dimensional

Hello everybody I'm using contour() to draw streamlines of potential flow, eg jj <- seq(from= -4, to=4,len=20) jj <- outer(jj,jj,function(x,y){x})+1i*outer(jj,jj,function(x,y){y}) f <- function(x){x^2} contour(Im(f(jj)), nlevels=44 , labels="") How best to put arrows on the contour lines to show the direction of flow? (ie I want contour lines looking like

Hi I have a two-column integer matrix like this: R> jj [,1] [,2] [1,] -1 1 [2,] -2 2 [3,] -7 6 [4,] -8 7 [5,] -6 5 [6,] -9 8 [7,] -5 4 [8,] 3 -3 [9,] -10 9 [10,] -4 3 I want a diagnostic that detects whether a row is a multiple of the first row or not. In this case, this would be rows 1,2, and 8. How to do this

Hi If x <- 1:10 then x[5] <- 1i will promote x to be a complex vector. Suppose I have an S4 class "brob", and have functions is.brob(), as.brob(), as.numeric() and so forth (minimal self-contained code below). If x is numeric (1:10, say) and y is a brob, what is the best way to make x[5] <- y promote x to a brob in the same way as the complex example? Or is

Hello I am writing a replacement method for an S4 class and want to pass an additional argument to "[<-"() along the lines of "["()'s "drop" argument. Specifically, I have an S4 class, call it "foo", with a slot 'x' that is a vector and a slot 'NC' that is a scalar. I want to be able to pass a Boolean argument to the

Hi I'm having difficulty with a multiple plot. What I want is 12 plots, all of which are the same size and shape, differing only in colour. Each one is a square, so there is an asp=1 in the plot call. I'm working in an Sweave environment so I am free to choose the height and width of the plot. I want the columns to be labelled at the head (here t=1,2,3) and the rows to be labelled at

Hi suppose I have two arrays x1,x2 of dimensions a1,b1,c1 and a2,b2,c2 respectively. I want x = x1 "+" x2 with dimensions c(max(a1,a2), max(b1,b2),max (c1,c2)) with x[a,b,c] = x1[a1,b1,c1] + x2[a2,b2,c2] if a <=min(a1,a2) , b<=min (b1,b2), c<=min(c1,c2) and the other bits either x1 or x2 or zero according to whether the coordinates are "in range" for

Hi I am having difficulty with apply(). I want apply() to return a matrix, but sometimes a vector is returned. Toy example follows. Function jj() takes a couple of matrices m1 and m2 as arguments and returns a matrix with r rows and c columns where r=nrow(m2) and c=nrow(m1). jj <- function(m1,m2,f,...){ apply(m1, 1, function(y) { apply(m2, 1, function(x) { f(x, y, ...)

Dear List I have just uploaded a new package, "onion", to CRAN. It provides some functionality for manipulating and visualizing quaternions and octonions. All comments welcome! enjoy rksh -- Robin Hankin Uncertainty Analyst National Oceanography Centre, Southampton European Way, Southampton SO14 3ZH, UK tel 023-8059-7743 _______________________________________________

Hi I have a square matrix Ainv of size N-by-N where N ~ 1000 I have a rectangular matrix H of size N by n where n ~ 4. I have a vector d of length N. I need X = solve(t(H) %*% Ainv %*% H) %*% t(H) %*% Ainv %*% d and H %*% X. It is possible to rewrite X in the recommended crossprod way: X <- solve(quad.form(Ainv, H), crossprod(crossprod(Ainv, H), d)) where quad.form() is a little

Hello list. I very often need 3d scatterplots, and use scatterplot3D quite a lot. I am trying to modify persp() to plot scatterplots, and make use of the theta and phi arguments that persp() offers. I am having some difficulty passing the correct arguments to persp(). Here is my function so far. Much of it is copied from the persp() manpage. points3d <- function(x,y,z,

Hello list. I very often need 3d scatterplots, and use scatterplot3D quite a lot. I am trying to modify persp() to plot scatterplots, and make use of the theta and phi arguments that persp() offers. I am having some difficulty passing the correct arguments to persp(). Here is my function so far. Much of it is copied from the persp() manpage. points3d <- function(x,y,z,

Hi, I am sure this has come up before, but my searches of the archive didn't give any results (maybe I didn't use the right keywords, but if I use too many, the search times out). I have a vector of dimensions n, length is not fixed, eg n <- c(4,5,7) or n <- c(19,4,5,7) and a function f that takes a vector of indices, same length of n, and gives a scalar. I would like to fill