Hey,
what is the R function for the mathematical limit ?
e.g. to calculate and return the amount that the expression
X^2 +X +2
approach
as X approach 2
(X-> 2)
thanks
hassan
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Dear R User I am using JGR on a Linux Ubuntu Computer with 2 Cpus When Opening JGR, one Cpu goes up to 100% even if no calculation is yet started Did any of you already noticed this strange behaviour? Thanks for your help Andrea
Dear Hassam, Take a look at the section 5.8 in [1]. HTH, Jorge [1] http://cran.r-project.org/web/packages/Ryacas/vignettes/Ryacas.pdf On Tue, May 5, 2009 at 5:39 AM, Hassan Mohamed <hassan_hany_fahmy@yahoo.com>wrote:> Hey, > what is the R function for the mathematical limit ? > e.g. to calculate and return the amount that the expression > X^2 +X +2 > approach > as X approach 2 > (X-> 2) > thanks > hassan > > > > [[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. >[[alternative HTML version deleted]]
Hassan Mohamed wrote:> Hey, > what is the R function for the mathematical limit ? > e.g. to calculate and return the amount that the expression > X^2 +X +2 > approach > as X approach 2 > (X-> 2)So you want some software that can do symbolic calculations? In that case use other software. R is designed for numerical analyses. Uwe Ligges> thanks > hassan > > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at 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 at quantide.com wrote:> Dear R User > I am using JGR on a Linux Ubuntu Computer with 2 Cpus > When Opening JGR, one Cpu goes up to 100% even if no calculation is yet > started > Did any of you already noticed this strange behaviour?Does it take very long? On the first start it builds some databases and that takes some time if you have installed many packages. Uwe Ligges> Thanks for your help > Andrea > > ______________________________________________ > R-help at 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.
The point is that one Cpu stays at 100% for all time JGR is up. Any ideas? Andrea Uwe Ligges wrote:> > > r at quantide.com wrote: >> Dear R User >> I am using JGR on a Linux Ubuntu Computer with 2 Cpus >> When Opening JGR, one Cpu goes up to 100% even if no calculation is >> yet started >> Did any of you already noticed this strange behaviour? > > Does it take very long? On the first start it builds some databases > and that takes some time if you have installed many packages. > > Uwe Ligges > > >> Thanks for your help >> Andrea >> >> ______________________________________________ >> R-help at 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. >
On Tue, 05 May 2009 15:12:00 +0200 "r at quantide.com" <r at quantide.com> wrote: RC> The point is that one Cpu stays at 100% for all time JGR is up. RC> Any ideas? RC> Andrea I believe it is a bug with JGR. Unfortunately it is existing for quite some time now. (I am using Fedora Linux since years and try it from time to time.) Just try another gui like emacs with ess or rkward. hth Stefan
Uwe Ligges <ligges at statistik.tu-dortmund.de> wrote:> So you want some software that can do symbolic calculations? In that > case use other software. R is designed for numerical analyses.In particular, if you are looking for good free software, you might try Maxima. -- Mike Prager, NOAA, Beaufort, NC * Opinions expressed are personal and not represented otherwise. * Any use of tradenames does not constitute a NOAA endorsement.
Try the rSymPy or Ryacas packages. In the rSymPy code below the var command defines x as symbolic to sympy and then we perform the computation:> library(rSymPy)Loading required package: rJava> sympy("var('x')")[1] "x"> sympy("limit(x*x + x + 2, x, 2)")[1] "8" Or using devel version define x as symbolic first to sympy and then to R:> library(rSymPy) > source("http://rsympy.googlecode.com/svn/trunk/R/Sym.R") > sympy("var('x')")[1] "x"> x <- Sym("x") > limit(x*x + x + 2, x, 2)[1] "8" or using Ryacas:> library(Ryacas)Loading required package: XML> x <- Sym("x") > Limit(x^2+x+2, x, 2)[1] "Starting Yacas!" expression(8) More info is available here which you should read before using these packages: http://rsympy.googlecode.com http://ryacas.googlecode.com On Tue, May 5, 2009 at 5:39 AM, Hassan Mohamed <hassan_hany_fahmy at yahoo.com> wrote:> Hey, > what is the R function for the mathematical limit ? > e.g. to calculate ?and return the amount that the expression > X^2 +X +2 > approach > as X approach 2 > (X-> 2) > thanks > hassan > > > > ? ? ? ?[[alternative HTML version deleted]] > > ______________________________________________ > R-help at 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. >