Hi! For IEEE floating point systems e_mach= 2^-53 ~= 10^-16 in double precision.
> identical(seq(0.7, 0, by = -0.1),seq(0.7, 0, length = 8)) [1] FALSE > a<-seq(0.7, 0, by = -0.1) > b<-seq(0.7, 0, length = 8) > a==b [1] TRUE TRUE FALSE FALSE FALSE FALSE FALSE FALSE > (a-b)<10^-16 [1] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE > Its in the range of machine accuracy (precision). /Eryk. *********** REPLY SEPARATOR *********** On 9/3/2004 at 1:23 PM Henric Nilsson wrote: >>>Hi everyone, >>> >>>I've tried the below on R 1.9.1 and the 2004-08-30 builds of R 1.9.1 >>>Patched and R 2.0.0 on Windows 2000, and the results are consistent. >>> >>> > seq(0.5, 0, by = -0.1) >>>[1] 0.5 0.4 0.3 0.2 0.1 0.0 >>> >>> > seq(0.7, 0, by = -0.1) >>>[1] 7.000000e-01 6.000000e-01 5.000000e-01 4.000000e-01 >>>3.000000e-01 >>>2.000000e-01 1.000000e-01 -1.110223e-16 >>> >>>Is this really the intended behaviour? I ended up using >>> >>> > seq(0.7, 0, length = 8) >>>[1] 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 >>> >>>which does what I want. >>> >>>//Henric >>> >>>______________________________________________ >>>[EMAIL PROTECTED] mailing list >>>https://stat.ethz.ch/mailman/listinfo/r-help >>>PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Dipl. bio-chem. Witold Eryk Wolski @ MPI-Moleculare Genetic Ihnestrasse 63-73 14195 Berlin 'v' tel: 0049-30-83875219 / \ mail: [EMAIL PROTECTED] ---W-W---- http://www.molgen.mpg.de/~wolski [EMAIL PROTECTED] ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
