similar to: Floating point precision / guard digits? (PR#13771)

Hi (If you're wondering, this is a Project Euler question :)) If I wanted to calculate the sum of the digits in the decimal representation of 2^1000, what would be a good way to go about that? I've tried the following methods: # Calculate the sum of digits in the decimal representation of 2^n # Only works for smaller values of n bsum <- function(n) { s <- 0 e <-

Dear R developers, (Apologies about previous incomplete e-mail, I fat-fingered a keyboard shortcut)?? I recently upgraded to 3.2.3 and am getting mystifying errors with my in-development code (available at https://github.com/gertvv/gemtc/tree/feature/regression). Every few hundred LPs that I solve using the rcdd package will result in a SEGFAULT in the garbage collector (address 0x10, cause

Full_Name: D Kreil Version: 2.1.1 OS: HP-UX B.11.23 U ia64 0029870451 unlimited-user license Submission from: (NULL) (62.178.15.60) When the dependency readline is installed in a non-standard location the installation procedure fails. If using a non-standard installation location like --prefix=/bi/common --exec-prefix=/bi/arch the configure script default include and library paths should

Hi, Why sum() on a 10-item vector produces a different value than its counterpart on a 2-item vector? I understand the problems related to the arithmetic precision in storing decimal numbers in binary format, but shouldn't the errors be equal regardless of the method used? See my example: > options(digits=22) > x=rep(.1,10) > x [1] 0.10000000000000001 0.10000000000000001

Full_Name: D Kreil Version: 2.1.1 OS: HP-UX B.11.23 U ia64 0029870451 unlimited-user license Submission from: (NULL) (62.178.15.60) During compiliation, I get: ld: Unsatisfied symbol "finite" in file colors.o Fix: replace "finite" with R_FINITE in colors.c line 269. I have, this time, searched through the R-admin.html, but not found a mention. This is all a bit hard for me

Dear Friends, Here is an algorithm for finding concave hulls: http://get.dsi.uminho.pt/local/ Has anyone implemented such an algorithm in R? RSiteSearch('concave hull') didn't reveal one (I think). _____________________________ Professor Michael Kubovy University of Virginia Department of Psychology Postal Address: P.O.Box 400400, Charlottesville, VA 22904-4400 Express Parcels

Dear John, > I suggest that you look at the abilities of the mgcv package. > There are notes of mine at > > http://www.maths.anu.edu.au/%7Ejohnm/r-book/xtras/autosmooth.pdf > > that may help you get started. Thank?you very much for the suggestion and the link to your write-up, it was indeed very helpful! I have experimented with this library for a while now and am really happy

Hi, I have a data.frame that I need to construct iteratively. At the moment, I'm doing: d<-data.frame(x=c(),y=c(),z=()); # {and, within some loop} d<-rbind(d,data.frame(x=newx,y=newy,z=newz); While this works, it is horribly verbose and probably not efficient, either. My real data.frame has, of course, many more columns, which can be of different modes. I vaguely recall that

Dear R-users and experts, I have been using the following code in earlier versions of R: q[,names(info)]<-info[no,]; with > class(info) [1] "data.frame" > class(q) [1] "data.frame" > dim(q) [1] 7488 68 > dim(info) [1] 12 8 > dim(info[no,]) [1] 1 8 The column names(info) did not exist in q before the assignment. What used to happen (as intended) was

Does anyone know precisely what is different about the arithmetic and/or storage of double precision floating point to produce the following differences between the Sun and Windows versions (Splus 6 on the same Windows 2000 machine gives the same results as Solaris)? R 1.6.1, Sun Solaris, gcc + an old Sun f77 > options(digits=20) > 1+(1/2^53+1/2^106) [1] 1 > 1+(1/2^53+1/2^105) [1]

OK, my journey to make lab machines automagically install & update all desirable R packages is nearing an end! The only question I have now is this: How can I control where the system prints the *.Rout file that is created automatically when the R batch program runs. In "man R" I don't find any information about it. When the cron job runs "R_installAll.sh" (see

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Dear R experts, I have a problem that is a related to the question raised in this earlier post https://stat.ethz.ch/pipermail/r-help/2007-January/124064.html My situation is different in that I have only 2 predictors (coordinates x,y) for local regression but a number of global ("parametric") offsets that I need to consider. Essentially, I have a spatial distortion overlaid over a

I upgraded from Fedora Core 4 to Fedora Core 5 and I find a lot of previously installed packages won't run because shared libraries or other system things have changed "out from under" the installed R libraries. I do not know for sure if the R version now from Fedora-Extras (2.2.1) is exactly the same one I was using in FC4. I see problems in many packages. Example, Hmisc: unable

Dear all, I have a sample with 920 observations. I want to create a loop which takes 300 of these observations for the prediction and the rest to estimate the model. My idea was to create something like this: cs.training.dat <- read.table... cs.training.dat_sub1 <- subset(cs.training.dat, Income>10) cs.training.dat_sub2 <- subset(cs.training.dat_sub1, Dept.Ratio<=1)

Hello, is there a possibilty in R to convert numbers (double precision, 64bit) into single precision ones (32bit). I need that for compatibility reasons. Until now I call a C application which casts a double to a float. float precision32(double value) { return (float)value; } But I want to use a R only method. What can I do? Kind regards, Sebastian

Dear All For my calculations, I am needing to use more floating-point precision than the default one of R. Is that possible? And, if yes, how? Thanks in advance, Paul

I'm having a function of the form 1> f<-function(x){ 1+ 1+ return(x^p) 1+ 1+ } ,and I would like to integrate it with respect to x, where p should be any constant. One way would be to set a value for p globally and then call integrate function: p=2 integrate(f, lower = -1, upper = 1) However, I would like to use 'integrate' inside a function, so I could call it passing

Has anyone come across the right combinations to print a limited number of digits? My trial and error approach is taking too much time. Here is what I have tried: > op <- options() > a <- c(1e-10,1,2,3,.5,.25) > names(a) <- c("A", "B", "C", "D", "E", "F") > # default > a A B C D

Hi, I am using randomForests for a classification problem. The predict function in the randomForest library, when asked to return the probabilities, has precision of two digits after the decimal. I need at least four digits of precision for the predicted probabilities. How do I achieve this? Thank you, Nagu