search for: brobs

Displaying 15 results from an estimated 15 matches for "brobs".

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2006 Oct 31
1
setReplaceMethod
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
2006 Sep 15
1
setMethod() woes
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
2006 Aug 30
1
setMethod() and log()
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
2008 May 28
1
indexing lists, using brobdingnagian
Dear R-Gurus, I have ended up with a calculation problem where I need to use brobs. I have to work my way through a vector with a for loop to act on each element in a calculation (refering to the previous value in the new vector of results -- so as far as I know I can't use "apply") -- this produces a list of brobs. My problem is, how do I act on, plot this list, o...
2006 Sep 04
1
setMethod("Summary")
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 unnamed. OK, so what is the correct procedure to make sum() o...
2010 Oct 08
2
Error message in as.brob Usage
I am getting the following error message while using the as.brob function in some computations: Error in out.x[ss] <- pmax(x1[ss], x2[ss]) + log1p(+exp(-abs(x1[ss] - : NAs are not allowed in subscripted assignments Is there any obvious mistake I am making here that can resolve the above error message? Thanks for your help. Chow -- View this message in context:
2006 Sep 01
1
setMethod("Logic", ...)
Hi In V&R the "polynomial" class is explicitly specified to have no logical operators: setMethod("Logic", signature(e1="polynomial"), function(e1,e2){stop ("...")}) I too have a class of objects for which I want to specify that Logic operators do not work, but executing setClass("brob", representation = representation
2007 Aug 30
7
Behaviour of very large numbers
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]
2007 Nov 21
1
equivalent of Matlab robustfit?
Hi, I've been using the Matlab robustfit function for linear regressions where I suspect some data points are outliers. Is there an equivalent function in R? Take care, Darren PS, This is the Matlab help on robustfit: >> help robustfit ROBUSTFIT Robust linear regression B = ROBUSTFIT(X,Y) returns the vector B of regression coefficients, obtained by performing robust
2006 Sep 12
1
package.skeleton() in R-2.4.1
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
2009 Feb 11
5
How to handle large numbers?
Dear R, I have two questions: 1, Why both R and Matlab give 0*Inf==NaN? To my knowledge, it should be zero mathematically. Am I right? 2, I need to calculate e.g. exp(a)/(exp(b)+c), where both a and b are very large numbers (>>1000, e.g a=1000, b=1007, and c=5). R gives me NaN when I use the following command: > exp(1000)/(exp(1007)+5) [1] NaN I am pretty sure this should be close to
2007 Jan 12
0
Dummy's guide to S4 methods: package Brobdingnag
Hello List. please find uploaded to CRAN a new package, Brobdingnag. This package does two things: (1) allows computation of very large numbers using a logarithmic representation. (2) provides a "Hello, World" example of S4 methods in use: there are two classes of object (brob and glub) and one virtual class (swift). The package includes a vignette that is a
2008 Sep 16
0
FW: odesolve dynload example
HI R Gurus, > This is my first foray into using c-code with R, so ... > I had a look at the archives and did not find anything on this, so > hopefully I am not doubling up. > I have previously used the following approach where I needed some very small numbers/large (using Brobdingnag): surfacewithdiff <- function(t, y, p) { const=p["const"] kay
2008 Sep 16
0
lsoda( linking to GMP for big numbers from C code)
Hi R used with C-code experts, I had a look at the archives and did not find anything on this, so hopefully I am not doubling up. I have previously used the following approach where I needed some very small/large numbers (using Brobdingnag): surfacewithdiff <- function(t, y, p) { const=p["const"] kay =p["kay"] psii=p["psii"]
2008 May 21
2
\S4method in combination with "[" and "[<-"
Dear developers, We want to use "\S4method" to document new S4-methods for "[" and "[<-". We use this for other functions/methods and it works without any problem, but in case of "[" and "[<-" we didn't manage to bring this to work. The problem occurs in the development version of our package "distrSim" which can be found