I can plot this just fine: t<-seq(0,4, by=.1) y<- t^3-6*t^2+5*t+30 plot(t,y ,xlab="t-values", ylab="f(t)", type="l") This is the first derivative, how I I make a similar plot? t<-seq(0,4, by=.1) y<- t^3-6*t^2+5*t+30 y1<-D(expression(t^3-6*t^2+5*t+30), 't')
Thanks ahead of time. kc On Fri, Jan 22, 2010 at 12:41 PM, Doran, Harold <hdo...@air.org> wrote: > > D(expression(t^3-6*t^2+5*t + 30), 't') > 3 * t^2 - 6 * (2 * t) + 5 > > > D(D(expression(t^3-6*t^2+5*t + 30), 't'), 't') > 3 * (2 * t) - 6 * 2 > > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] > On Behalf Of Marlin Keith Cox > Sent: Friday, January 22, 2010 4:37 PM > To: r-help@r-project.org > Subject: [R] first and second derivative calculation > > I would like to calculate a first and second derivative and am having > problems finding a simple solution. My syntax may be off as I am not a > mathematician, so pardon ahead of time. > data: > t<-seq(0,4, by=.1) > The function is: > H(t) = t^3-6*t^2+5*t + 30 > > from here I plot the curve: > plot(x,y ,xlab="x-values", ylab="f(x)", type="l") > But would like to similarly plot the curve for both the first and second > derivatives. > I can calculate the derivatives by hand but would like to get R to do this > for me. > by hand: > H'(t) = 3*t^2 - 12*t + 5 > H''(t) = 6*t-12 > Keith > > -- > M. Keith Cox, Ph.D. > Alaska NOAA Fisheries, National Marine Fisheries Service > Auke Bay Laboratories > 17109 Pt. Lena Loop Rd. > Juneau, AK 99801 > keith....@noaa.gov > marlink...@gmail.com > U.S. (907) 789-6603 > > [[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<http://www.r-project.org/posting-guide.html> > and provide commented, minimal, self-contained, reproducible code. > -- M. Keith Cox, Ph.D. Alaska NOAA Fisheries, National Marine Fisheries Service Auke Bay Laboratories 17109 Pt. Lena Loop Rd. Juneau, AK 99801 keith....@noaa.gov marlink...@gmail.com U.S. (907) 789-6603 [[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.
