> 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 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.