On 4/18/2011 9:12 AM, salmajj wrote:
hi! there is a bug with the IF operator that is really dangerous! please try the code below and if someone could explain to me why when (q is equal to 0.8, 0.9 or 1) R do not print it?q=0 for (j in 1:11){ if ((q==1)){ print(q) } q=q+0.1 } so in this code q is incremented from 0 to 1.1. but R do not capture print the value 1, 0.8 and 0.9 !! try to change (q==0.4) it gonna print 0.4. but if you put q==0.8 or 0.9 or 1 it doesn't work!!! please try it it is amazing!!!
It is not a bug. It a misunderstanding on your part of the limits of floating point arithmetic. See FAQ 7.31 (and multiple previous discussions on this and the r-help list).
http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-doesn_0027t-R-think-these-numbers-are-equal_003f
-- View this message in context: http://r.789695.n4.nabble.com/Dangerous-Bug-with-IF-function-of-R-tp3457976p3457976.html Sent from the R devel mailing list archive at Nabble.com.
-- Brian S. Diggs, PhD Senior Research Associate, Department of Surgery Oregon Health & Science University ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
