search for: equal_003f

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.

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]

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 >

...,.3,.6)) [1] (0,0.3] (0,0.3] (0.3,0.6] (0.3,0.6] (0.3,0.6] Levels: (0,0.3] (0.3,0.6] I'm sure this is probably the same issue documented in the FAQ (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 [1] Is there a way to make cut work correctly (a code fix)? [2] Is there a workaround for using the current cut? [3] Why does 'hist' work correctly on the same data? > table(cut(x, br=c(0,.3,.6))) (0,0.3] (0.3,0.6] 2 3 > hist(x, br=c(0,.3,.6), plot=F)$counts [1]...

Hi, Check the FAQ 7.31 https://cran.rstudio.com/doc/FAQ/R-FAQ.html#Why-doesn_0027t-R-think-these-numbers-are-equal_003f And read the posting guide too... https://www.r-project.org/posting-guide.html HTH, Ivan -- Dr. Ivan Calandra TraCEr, Laboratory for Traceology and Controlled Experiments MONREPOS Archaeological Research Centre and Museum for Human Behavioural Evolution Schloss Monrepos 56567 Neuwied, Germany +4...

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, please see my code: > library(zoo) > a <- as.yearmon("March-2010", "%B-%Y") > b <- as.yearmon("May-2010", "%B-%Y") > > nn <- (b-a)*12 # number of months in between them > nn [1] 2 > as.integer(nn) [1] 1 What is the correct way to find the number of months between "a" and "b", still

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 doing the prediction calculations manually. But doing that gave me problematic results (I won't go into the details of how I found that...

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

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]]

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:

> 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]]

Hi, I am not sure if this is just me using R (R-2.3.1 and R-2.4.0) in the wrong way or if there is a more serious bug. I was having problems getting some calculations to add up so I ran the following tests: > (2.34567 - 2.00000) == 0.34567 <------- should be true [1] FALSE > (2.23-2.00) == 0.23 <------- should be true [1] FALSE > 4-2==2 [1] TRUE > (4-2)==2 [1] TRUE >

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 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 >

To the R development team: First of all, thank you so much for maintaining wonderful R software. Perhaps, Dr. Ahn has just reported an error on the wilcox.test() function, and suggesting that an error may arise from abs() and rank(). I just had a quick check that the problem may come from the precision of the results of arithmetic functions. 87.7-89.1+1.4 # > 87.7-89.1+1.4 # [1]

Hi, has someone experience which routine should be used for creating fractional numbers? The two conversion routines deliver different results > x <- (0:7)/7 > MASS::fractions(x) [1] 0 1/7 2/7 3/7 4/7 5/7 6/7 1 > gmp::as.bigq(x) Big Rational ('bigq') object of length 8: [1] 0 2573485501354569/18014398509481984 2573485501354569/9007199254740992 [4]

...number might have been before an imprecise approximation of k/7 had been computed. (Since 7 is not a power of 2, only 0 and 1 have an exact representation in your example.) For more information, see R FAQ 7.31: https://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-doesn_0027t-R-think-these-numbers-are-equal_003f What do you need the fractions for? -- Best regards, Ivan

Dear all, Could someone please explain the following perculiarity? > 2 == 0.2/0.1 [1] TRUE > 3 == 0.3/0.1 [1] FALSE Similarly, floor(0.2/0.1) = 2 floor(0.3/0.1) = 2 Thank you, Simon