Just wanted to mention that the caracas package *may* be better at solving this problem Best Søren
-----Original Message----- From: Konrad via R-help <r-help@r-project.org> Reply-To: Konrad <konrad_krae...@yahoo.de> To: R-help@r-project.org Subject: [R] computer algebra in R Date: Tue, 28 Nov 2023 11:03:36 +0100 Dear all, I'm currently working on converting mathematica code (https://github.com/ASDSE/thermosimfit/blob/master/Packages/thermoHD-Comp/thermoCacheHD-1Comp.m) to R. The code is related to solve algebraic systems. > eqthermo = {h0 == h + hd + hga, d0 == d + hd, ga0 == ga + hga, kga == > hga / (h * ga), kd == hd / (h * d)}; > > (* IDA HD*) > sthdIDAcacheHD[fkd_, fkga_, fh0_, fd0_] := sthdIDAcacheHD[fkd, fkga, > fh0, fd0] = > Module[{eliHD, solvHD}, > eliHD = > Eliminate[ > eqthermo /. {d0 -> fd0, h0 -> fh0, kd -> fkd, kga -> > fkga}, {h, d, hga, ga}]; > solvHD = hd /. NSolve[eliHD, hd]; > Return[solvHD]; > ]; I tried to use the Ryacas package. However, I'm struggling with the Elimination step. Within this step a system of equations: 0.3==h+hd+hga,0.4==d+hd,ga0==ga+hga,0.2==hga/(ga h),0.1==hd/(d h) is transformed to: -12.+1040. hd+2575. hd^2-250. hd^3==ga0 hd (-200.+500. hd). My question is whether someone has experience with yacas and can tell me how to do this step in R. Beyond that, I would be grateful for every hint how to transfer this into R. All the best, Konrad ______________________________________________ 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. -- Søren Højsgaard Head of Department of Mathematical Sciences Aalborg University, Denmark. Chair of the Danish Statistical Society ______________________________________________ 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.
