but with complex, I get complex numbers for the first and last elements: > (as.complex(tmp))^(1/3) [1] 0.01969170+0.03410703i 0.03478442+0.00000000i 0.03285672+0.00000000i [4] 0.08950802+0.00000000i 0.05848363+0.10129661i
whereas for the first element, we get the followings. Moreover, > -6.108576e-05^(1/3) > [1] -0.03938341 and > -(6.108576e-05^(1/3)) [1] -0.03938341 and -((6.108576e-05)^(1/3)) [1] -0.03938341 give the same results. so using () doesn't preserve any thing --- On Mon, 11/16/09, Petr PIKAL <petr.pi...@precheza.cz> wrote: > From: Petr PIKAL <petr.pi...@precheza.cz> > Subject: Odp: [R] ^ operator > To: "carol white" <wht_...@yahoo.com> > Cc: r-h...@stat.math.ethz.ch > Date: Monday, November 16, 2009, 3:40 AM > Hi > > AFAIK, this is issue of the preference of operators. > > r-help-boun...@r-project.org > napsal dne 16.11.2009 11:24:59: > > > Hi, > > I want to apply ^ operator to a vector but it is > applied to some of the > > elements correctly and to some others, it generates > NaN. Why is it not > able to > > calculate -6.108576e-05^(1/3) even though it exists? > > > > > > tmp > > [1] -6.108576e-05 4.208762e-05 > 3.547092e-05 7.171101e-04 > -1.600269e-03 > > > tmp^(1/3) > > [1] NaN 0.03478442 > 0.03285672 0.08950802 NaN > > This computes (-a)^(1/3) which is not possible in real > numbers. You have > to use as.complex(tmp)^(1/3) to get a result. > > > > -6.108576e-05^(1/3) > > [1] -0.03938341 > > this is actually > -(6.108576e-05^(1/3)) > > Regards > Petr > > > > > > ______________________________________________ > > 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.