> > > x[x<0.2] > > [1] -1.00 -0.98 -0.96 -0.94 -0.92 -0.90 -0.88 -0.86 -0.84 -0.82 -0.80 > > -0.78
This is a bit off the original topic, but you should really put spaces around the "<". Otherwise you might be surprised when you compare x to -0.2 instead of +0.2: > x<-seq(-1,1,by=0.02) > x[x<-0.2] numeric(0) > x [1] 0.2 Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf > Of Duncan Murdoch > Sent: Wednesday, March 06, 2013 7:57 AM > To: Victor hyk > Cc: r-help@r-project.org > Subject: Re: [R] About basic logical operators > > On 05/03/2013 7:53 PM, Victor hyk wrote: > > Hello everyone, > > I have a basic question regarding logical operators. > > > x<-seq(-1,1,by=0.02) > > > x > > [1] -1.00 -0.98 -0.96 -0.94 -0.92 -0.90 -0.88 -0.86 -0.84 -0.82 -0.80 > > -0.78 > > [13] -0.76 -0.74 -0.72 -0.70 -0.68 -0.66 -0.64 -0.62 -0.60 -0.58 -0.56 > > -0.54 > > [25] -0.52 -0.50 -0.48 -0.46 -0.44 -0.42 -0.40 -0.38 -0.36 -0.34 -0.32 > > -0.30 > > [37] -0.28 -0.26 -0.24 -0.22 -0.20 -0.18 -0.16 -0.14 -0.12 -0.10 -0.08 > > -0.06 > > [49] -0.04 -0.02 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 > > 0.18 > > [61] 0.20 0.22 0.24 0.26 0.28 0.30 0.32 0.34 0.36 0.38 0.40 > > 0.42 > > [73] 0.44 0.46 0.48 0.50 0.52 0.54 0.56 0.58 0.60 0.62 0.64 > > 0.66 > > [85] 0.68 0.70 0.72 0.74 0.76 0.78 0.80 0.82 0.84 0.86 0.88 > > 0.90 > > [97] 0.92 0.94 0.96 0.98 1.00 > > > x[x<=0.02] > > [1] -1.00 -0.98 -0.96 -0.94 -0.92 -0.90 -0.88 -0.86 -0.84 -0.82 -0.80 > > -0.78 > > [13] -0.76 -0.74 -0.72 -0.70 -0.68 -0.66 -0.64 -0.62 -0.60 -0.58 -0.56 -0.54 > > [25] -0.52 -0.50 -0.48 -0.46 -0.44 -0.42 -0.40 -0.38 -0.36 -0.34 -0.32 -0.30 > > [37] -0.28 -0.26 -0.24 -0.22 -0.20 -0.18 -0.16 -0.14 -0.12 -0.10 -0.08 -0.06 > > [49] -0.04 -0.02 0.00 > > > x[x<0.2] > > [1] -1.00 -0.98 -0.96 -0.94 -0.92 -0.90 -0.88 -0.86 -0.84 -0.82 -0.80 > > -0.78 > > [13] -0.76 -0.74 -0.72 -0.70 -0.68 -0.66 -0.64 -0.62 -0.60 -0.58 -0.56 -0.54 > > [25] -0.52 -0.50 -0.48 -0.46 -0.44 -0.42 -0.40 -0.38 -0.36 -0.34 -0.32 -0.30 > > [37] -0.28 -0.26 -0.24 -0.22 -0.20 -0.18 -0.16 -0.14 -0.12 -0.10 -0.08 -0.06 > > [49] -0.04 -0.02 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 > > [61] 0.20 > > > > > Why does "x[x<=0.02]" return no 0.02 > > You don't have a 0.02 in your dataset. Evaluate x[52] - 0.02 and you > won't get zero due to rounding (as Jeff said, see FAQ 7.31). > > but "x[x<0.2]" return a subsample with 0.02? > > You don't have 0.2, either. Evaluate x[61] - 0.2 and you get a negative > value. > > Duncan Murdoch > > > Anyone who can tell me why? > > Thanks! > > > > Victor > > > > [[alternative HTML version deleted]] > > > > > > > > ______________________________________________ > > R-help@r-project.org mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > > and provide commented, minimal, self-contained, reproducible code. > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.