similar to: setMethod("Logic", ...)

Hi I am having difficulty with setMethod(). I have a "brob" class of objects whose representation has two slots: "x" and "positive". Slot "x" (double) holds the log of a number and slot "positive" (logical) its sign. The idea is that large numbers can be handled. I'm trying to implement a log() method using an analogue of the

Hello everybody R version 2.4.0 alpha (2006-09-15 r39323), MacOSX 10.4.7 Next S4 problem. I have "brob" objects that are large real numbers, and now I want "glub" numbers that are to be a pair of glubs that represent complex numbers. I want to define binary operator "+" so that if either the left or right argument are glubs, it uses .ArithGlub. If either

Hi everyone and thanks for being patient. I've used "!.foo"() et seq pro tem. Next problem: how to define "Summary" methods for brobs. ?max says 'max' and 'min' are generic functions: methods can be defined for them individually or via the 'Summary' group generic. For this to work properly, the arguments '...' should be

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

Hi R version 2.4.0 alpha (2006-09-06 r39158) MacOSX 10.4.7 There was a thread some time ago as to whether the structure created by package.skeleton() would pass R CMD check. I have an example where package.skeleton() gives an R file that gives an error when sourced. If I type setClass("brob", representation = representation

Dear all, I am struggling to understand this. What happens when you raise a negative value to a power and the result is a very large number? B [1] 47.73092 > -51^B [1] -3.190824e+81 # seems fine # now this: > x <- seq(-51,-49,length=100) > x^B [1] NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN <snip> > is.numeric(x^B) [1] TRUE > is.real(x^B) [1]

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 Suppose I have an S4 class "foo" and a validity checking function ".checkfoo()": setClass("foo", representation=representation("numeric")) setValidity("foo" , .checkfoo) is fine; in my application, .checkfoo() verifies that a bunch of necessary conditions are met. But .checkfoo() is very time consuming and I want to give users the option

Hi has anyone coded up domain colouring for visualizing complex analytic functions (such as elliptic functions)? [ the idea is to depict a complex function f(z) using a filled.contour() variant in which the hue is given by Arg(f(z)), and the saturation by Mod(f(z)). ] -- Robin Hankin Uncertainty Analyst Southampton Oceanography Centre European Way, Southampton SO14 3ZH, UK tel

Hi If string <- "xyz" f <- function(x){1 + sin(cos(x)) + exp(x^2)} How do I manipulate "string" and f() to give the string "1 + sin(cos(xyz)) + exp(xyz^2)" ? -- Robin Hankin Uncertainty Analyst National Oceanography Centre, Southampton European Way, Southampton SO14 3ZH, UK tel 023-8059-7743

Hi In Sweave, how does one change the size of the plots? I tried using a hook: <<echo=FALSE, print=FALSE, fig=TRUE>>= options(SweaveHooks=list(fig=function() ps.options(width=1))) library(graphics) pairs(iris) @ but this didn't change the size of the figure. How to make the figures a different size? -- Robin Hankin Uncertainty Analyst National Oceanography Centre,

Hi. I have a factor and I want to extract just those elements that appear exactly once. How to do this? Toy example follows. > a <- as.factor(c(rep("oak",5) ,rep("ash",1),rep("elm",1),rep ("beech",4))) > a [1] oak oak oak oak oak ash elm beech beech beech beech Levels: ash beech elm oak > table(a) a ash beech elm oak

Hi. Is there a straightforward way to convert a character string containing comma-delimited numbers to a numeric vector? In my application, I use system(executable.string, intern=TRUE) which returns a string like "[0.E-38, 2.096751179214927596171268230, 3.678944959657480671183123052, 4.976528845643001020345216157, 6.072390165503099343887569007, 7.007958550337542210168866070,

Hi ?lines says For 'type = "h"', 'col' can be a vector and will be recycled as needed. Why doesn't lines() recycle colours for other types? If I type > plot(0:1,0:1,type="n") > lines(runif(11),runif(11),col=c("red","green")) > then all ten lines are red, with no warning given. Is there a reason why

Hi How do I specify an S4 class with a slot that is potentially numeric, but NA by default? I want the slot to be NA until I calculate its value (an expensive operation, not needed for all applications). When its value is known, I will create a new object with the correct value inserted in the slot. I want "NA" to signify "not known". My attempt fails because

Hi I have a little vector function that takes a vector A of strictly positive integers and outputs a matrix M each of whose columns is the vector, modified in a complicated combinatorical way. Now I want to generalize the function so that A can include zeroes. Given A, I want to strip out the zeroes, pass it to my function, and pad M with rows at positions corresponding to the zeroes

Hi I'm developing an R package that needs to execute some code written in pari/gp. I've used this before from an R package (elliptic) but the interface is very basic: the R function creates a string such as the following: string <- echo ' ellwp ([ 2+0*I , 0+2*I ], 1+0*I )' | gp -q And then system(string) returns the output from gp which then needs to be text processed

Hi [this after some considerable thought as to R-help vs R-devel] I want to write a (S3) method for as.function(); toy example follows. Given a matrix "a", I need to evaluate trace(ax) as a function of (matrix) "x". Here's a trace function: tr <- function (a) { i <- seq_len(nrow(a)) return(sum(a[cbind(i, i)])) } How do I accomplish the following:

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,

The following gotcha caught me off-guard just now. I have two matrices, a and b: a <- matrix(1,3,3) b <- matrix(1,1,1) (note that both "a" and "b" are matrices). I want them in a list: > B <- NULL > B[[1]] <- a > B[[2]] <- b > B [[1]] [,1] [,2] [,3] [1,] 1 1 1 [2,] 1 1 1 [3,] 1 1 1 [[2]] [,1] [1,] 1