similar to: Inaccurate result for 0. (PR#13538)

Hi, there, I cannot get accurate value for calculation. for example: ld<-sqrt(1*0.05*0.95*0.05*0.95) 0.05*0.95-ld=-6.938894e-18 0.05*0.95-ld==0 is False. I met this problem in my program, how can I handle it. Thanks. xj.

Dear developer, in my version of R (2.4.0) as weel as in a more recent version (2.6.0) on different computers, we found this problem : > a<-(58/40-1) > a [1] 0.45 > b<-(18/40) > b [1] 0.45 > a<b [1] TRUE > a==b [1] FALSE > Something seems wrong here. but if we do > c<-0.45 > d<-0.45 > c<d [1] FALSE then everything is ok. If we use 59

dear all, I report a problem very simple, that I does non know how to handle. look at the following code: > a = rep(16.256, 5) > sum(a[1:5]^2) - (sum(a[1:5])^2/5) [1] 2.273737e-13 as you can see i retrieve a non 0 value, when i am expected to. what can I do? > sessionInfo() R version 2.6.2 (2008-02-08) i386-pc-mingw32 locale:

Full_Name: jan hattendorf Version: 2.9.0 OS: XP Submission from: (NULL) (213.3.108.185) I get an incorrect result for (41/10-1/10)%%1 [1] 1 The error did not occur with other numbers than 41 (1, 11, 21, 31, 51, ...) test <- rep(NA, 1000) for(i in 1:1000){ test[i] <- i/10-1/10 } test[test%%1==0]

Dear R Helpers, I am trying to extract the modulus from divisions by a sequence of fractions. I noticed that %% seems to behave inconsistently (to my untutored eye), thus: > 0.1%%0.1 [1] 0 > 0.2%%0.1 [1] 0 > 0.3%%0.1 [1] 0.1 > 0.4%%0.1 [1] 0 > 0.5%%0.1 [1] 0.1 > 0.6%%0.1 [1] 0.1 > 0.7%%0.1 [1] 0.1 > 0.8%%0.1 [1] 0 > 0.9%%0.1 The modulus for 0.1, 0.2, 0.4 and 0.8 is

Hi, I'm having trouble with the "which" or the "seq" function, I'm not sure. Here's an example : > lat=seq(1,2,by=0.1) > lat [1] 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 > which(lat==1) [1] 1 > which(lat==1.1) [1] 2 > which(lat==1.2) [1] 3 > which(lat==1.3) [1] 4 > which(lat==1.4) [1] 5 > which(lat==1.5) [1] 6 >

Dear colleagues Please could someone kindly explain the following inconsistencies I've discovered when performing logical calculations in R: 8.8 - 7.8 > 1 > TRUE 8.3 - 7.3 > 1 > TRUE Thank you, Emma Jane [[alternative HTML version deleted]]

Hi all, In checking my R codes, I encountered the following problem. Is there a way to fix this? I tried to specify options(digits=). I did not fix the problem. Thanks so much for your help! Hanna > cdf(pmass)[2,2]==pcum[2,2][1] FALSE> cdf(pmass)[2,2][1] 0.9999758> pcum[2,2][1] 0.9999758 [[alternative HTML version deleted]]

Hi everyone, after following in the footsteps of the following discussion (http://lists.xenproject.org/archives/html/xen-users/2013-09/msg00106.html) I had been able to turn my GTX 480 into a Quadro 6000. When I VT-d passthrough it to a Debian jessie VM it shows up fine and CUDA 5.5 seems to function properly up to a point: lspci -v: 00:04.0 VGA compatible controller: NVIDIA Corporation GF100GL

> length(sample(25000, 25000*(1-.55))) [1] 11249 > 25000*(1-.55) [1] 11250 > length(sample(25000, 11250)) [1] 11250 > length(sample(25000, 25000*.45)) [1] 11250 So the question is, why do I get 11249 out of the first command and not 11250? I can't figure this one out. Thanks Cory [[alternative HTML version deleted]]

Perhaps somebody could clarify for me if the following is a floating point matter or otherwise, and how am I to correct for it? > floor(100*.1) [1] 10 > 100*(1.0-.9) [1] 10 > floor(100*(1-0.9)) [1] 9 Thanks! Michael _______________________________________________________ Michael Folkes Salmon Stock Assessment Canadian Dept. of Fisheries & Oceans Pacific Biological Station

Hi, I'm using the '%%' operator in some code, and am running into the following erroneous outcome: > 1.2 %% 0.2 [1] 0.2 Unless I'm very mistaken, the result should be 0 (indeed, 12 %% 2 does result in 0). Furthermore: > 1.20000000000000001 %% 0.2 [1] 0.2 > (1.2+1e17) %% .2 [1] 0 Warning message: probable complete loss of accuracy in modulus (Warning

Using the following version of R: > R version 2.4.1 (2006-12-18) installed using apt-get on a Debian/Sarge AMD64 system with the following entry in /etc/apt/sources.lists: deb http://www.stats.bris.ac.uk/R/bin/linux/debian/ stable/ The problem: I'm seeing strange results in a integer calculation as follows: > choose(11,6) > [1] 462 > as.integer(choose(11,6)) > [1] 461

Hi R, I have certain checkings, which gives FALSE, but actually it is true. Why does this happen? Note that the equations that I am checking below are not even the case of recurring decimals... > 1.4^2 == 1.96 [1] FALSE > 1.2^3==1.728 [1] FALSE Thanks in advance, Shubha Shubha Karanth | Amba Research Ph +91 80 3980 8031 | Mob +91 94 4886 4510 Bangalore * Colombo *

Hi All, I recently encountered results that I did not expect, exhibited by the following code snippet: test <- function() { minX <- 4.2 min0 <- 4.1 sigmaG <- 0.1 Diff <- minX-min0 print(c(Diff=Diff,sigmaG=sigmaG)) cat("is Diff > sigmaG?:", Diff > sigmaG,"\n") cat("is (4.2 - 4.1) > 0.1?:",(4.2 - 4.1) >

Hi, I apologize if there is a simple answer to this question that I've missed. I did search the mailing list but I might not have used the right keywords. Why does sum(A3^2) give the result of 1, but sum(A3^2)==1 give the result of FALSE? > A3<-matrix(nrow=3,c(1/(2^.5),1/(2^.5),0)) > A3 [,1] [1,] 0.7071068 [2,] 0.7071068 [3,] 0.0000000 > sum(A3^2) [1] 1 >

Hello, here is the version of R that I use : > version _ platform i486-pc-linux-gnu arch i486 os linux-gnu system i486, linux-gnu status major 2 minor 3.1 year 2006 month 06 day 01 svn rev 38247 language R version.string Version 2.3.1 (2006-06-01) And here is one of the sequences of

Do you heve any idea why I get after this instruction everywhere false? > seq (0, 1, by=0.1) == 0.3 [1] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE But after different step it's ok: > seq(0, 1, by=0.1) == 0.4 [1] FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE FALSE FALSE -- View this message in context:

A scsi error (caused possibly by a loose cable) has left the processes accessing my ext3 file system hung in an unkillable state after it triggered an assert in ext3's journaling layer. I assume my only recourse at this point is to reboot. Please correct me if I'm wrong. Log messages appended. Thanks, -Jim Nov 21 04:04:04 attila kernel: SCSI disk error : host 0 channel 0 id 5 lun 0

Hello dear r-help group I am turning for you for help with FAQ number 7.31: "Why doesn't R think these numbers are equal?" http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-doesn_0027t-R-think-these-numbers-are-equal_003f *My story* is this: I wish to run many lm predictions and need to have them run fast. Using predict.lm is relatively slow, so I tried having it run faster by