If you need to solve a nonlinear system of equations you could have a look at the CRAN Task View: Numerical Mathematics: https://cran.r-project.org/view=NumericalMathematics
Specifically look in the subsection "Root Finding and Fixed Points". Berend Hasselman > On 19 Jan 2023, at 10:41, Troels Ring <tr...@gvdnet.dk> wrote: > > Hi friends - I hope this is not a misplaced question. From the literature > (Kushmerick AJP 1997;272:C1739-C1747) I have a series of Mathematica > equations which are solved together to yield over different pH values the > concentrations of metabolites in skeletal muscle using the Mathematica > function FindRoot((E1,E2...),(V2,V2..)] where E is a list of equations and V > list of variables. Most of the equations are individual binding reactions of > the form 10^6.494*atp*h == hatp and next 10^9.944*hatp*h ==hhatp describing > binding of singe protons or Mg or K to ATP or creatin for example, but we > also have constraints giving total concentrations of say ATP i.e. ATP + ATPH, > ATPH2..ATP.Mg > > I have, without success, tried to find ways to do this in R - I have 36 > equations on 36 variables and 8 equations on total concentrations. As far as > I can see from the definition of FindRoot in Wolfram, Newton search or secant > search is employed. > > I'm on Windows R 4.2.2 > > Best wishes > Troels Ring, MD > Aalborg, Denmark > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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 -- To UNSUBSCRIBE and more, see 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.
