this is where you should be using parenthesis to make sure you have the correct precedence of operations:
> -0.5^(1/5) [1] -0.8705506 > (-0.5)^(1/5) [1] NaN > > x <- -0.5 > x^(1/5) [1] NaN > Jim Holtman Data Munger Guru What is the problem that you are trying to solve? Tell me what you want to do, not how you want to do it. On Tue, May 17, 2016 at 9:09 AM, David Pell <[email protected]> wrote: > Try : > > -0.5^(1/5) > [1] -0.8705506 > > David > > > -----Original Message----- > From: R-sig-teaching [mailto:[email protected]] On > Behalf Of Steven Stoline > Sent: 17 May 2016 14:07 > To: jim holtman <[email protected]> > Cc: R-sig-teaching <[email protected]> > Subject: Re: [R-sig-teaching] Plot f(x) = x^(1/5) > > Dear All: > > in my TI-Calculator (-0.5)^(1/5) = -0.8705, but in R (-0.5)^(1/5) = NaN. > > > with thanks > steve > > On Tue, May 17, 2016 at 8:52 AM, jim holtman <[email protected]> wrote: > > > System is working correctly. A negative number cannot be raised to a > > fractional power: > > > > > (-2)^(1/5) > > [1] NaN > > > > > > > > > > Jim Holtman > > Data Munger Guru > > > > What is the problem that you are trying to solve? > > Tell me what you want to do, not how you want to do it. > > > > On Tue, May 17, 2016 at 8:44 AM, Steven Stoline <[email protected]> > > wrote: > > > >> Dear All: > >> > >> > >> I am trying to plot the function f(x) = x^(1/5) for x=seq(-2,2,0.01). > >> It give me only the plot of f(x) for the positive part of x. I > >> checked the values of f(x), it is NaN for all negative values of x. > >> > >> *this is my code:* > >> > >> > >> x<-seq(-2,2,0.01) > >> y<- (x)^(1/5) > >> plot(x,y, type="l", lwd=3, xlab = " ", ylab = " ", col="blue") > >> abline(v=0, col="gray", lty=2, lwd=3) abline(h=0, col="gray", lty=2, > >> lwd=3) > >> > >> > >> > >> any help will be appreciated. > >> > >> > >> with many thanks > >> steve > >> -- > >> Steven M. Stoline > >> 1123 Forest Avenue > >> Portland, ME 04112 > >> [email protected] > >> > >> [[alternative HTML version deleted]] > >> > >> _______________________________________________ > >> [email protected] mailing list > >> https://stat.ethz.ch/mailman/listinfo/r-sig-teaching > >> > > > > > > > -- > Steven M. Stoline > 1123 Forest Avenue > Portland, ME 04112 > [email protected] > > [[alternative HTML version deleted]] > > _______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-sig-teaching > > ________________________________ > > > This email may have a protective marking please see > http://www.mrc.ac.uk/about/information-standards/document-marking-policy/ > <http://www.mrc.ac.uk/about/information-standards/document-marking-policy/ > > > > This email and any attachments are intended for the na...{{dropped:22}} _______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-sig-teaching
