search for: ryacas

Ryacas is an R interface to the free yacas computer algebra system. Ryacas allows one to send R expressions, unprocessed yacas strings and certain other R objects to a separate yacas process from R and get back the result. It also has facilities for manipulating yacas strings and R expressions destined...

Ryacas is an R interface to the free yacas computer algebra system. Ryacas allows one to send R expressions, unprocessed yacas strings and certain other R objects to a separate yacas process from R and get back the result. It also has facilities for manipulating yacas strings and R expressions destined...

Ryacas is an R interface to the free yacas computer algebra system. Ryacas allows one to send R expressions, unprocessed yacas strings and certain other R objects to a separate yacas process from R and get back the result. It also has facilities for manipulating yacas strings and R expressions destined...

Ryacas is now available on CRAN. (Previously it was available on the Omegahat repository.) Ryacas is an R package that provides an interface from R to the yacas computer algebra system. It can be used for computer algebra, exact arithmetic, ASCII pretty printing and R to TeX output. R, yacas and Ryaca...

Ryacas is now available on CRAN. (Previously it was available on the Omegahat repository.) Ryacas is an R package that provides an interface from R to the yacas computer algebra system. It can be used for computer algebra, exact arithmetic, ASCII pretty printing and R to TeX output. R, yacas and Ryaca...

Has anyone successfully used Rcmd install or Rcmd check on Windows Vista? I have been successfully been running R itself, just not Rcmd install and Rcmd check. Rcmd check fails, the Ryacas.Rcheck it creates is read-only, I don't have permission to delete it and I have to reset the permissions on it just to delete it. With Rcmd install I am getting the following which looks like I am running into permissions problems and, of course, these also show up in Rcmd check. I had instal...

I'm tinkering around in Ryacas trying to find an easy way to get the first and second partial derivatives of mu and sigma from a normal distribution (actually a bitterly ugly likelihood but this example works for now). I've done all of the work in Mathematica, but I then need to manually write R code whereas I think Ryacas...

I'm having trouble loading Ryacas. I've downloaded and extracted Ryacas 0.2-9 (also tried Ryacas ) and yacas 1.0.63, have the latest version of R and have tried the following (this works for installing other packages): install.packages("Ryacas") library(Ryacas) install.packages("yacas") library(yacas) and...

I am having issues with Ryacas errors. I searched and found this error was reported in 2006, but nothing since. > library(Ryacas) Loading required package: XML > yacas(expression(Factor(x^2-1))) [1] "Starting Yacas!" CommandLine(1) : Expecting ) closing bracket for sub-expression, but got ^ instead > yacas...

Hello yet again, R People: I was working with Ryacas and yacas last night and all was well. Now this morning, I keep getting the following: > a <- Sym("a") > a Error in summary.connection(x) : invalid connection > When I go to yacas from the command line, it works fine. Any suggestions, please? I'm thinking that a port...

Thanks for the response. Yes, I did study the vignette but did not understand it fully. Anyway, I have tried once again now. I am happy to say that I have got what I wanted. library(Ryacas) x <- Sym("x");U <- Sym("U");x0 <- Sym("x0");C <- Sym("C") my_func <- function(x,U,x0,C) { return (U/(1+exp(-(x-x0)/C)))} FirstDeriv <- deriv(my_func(x,U,x0,C), x) PrettyForm(FirstDeriv) #slope <- yacas("Subst(x,x0),deriv(my_func(x...

...as(paste(x,"*",x)) > x expression(Inf^1.260864167e+117/Inf^6.304320836e+116) > Eval(x) [1] NaN No luck this way. However, I am successful with > y <- yacas("(3/2)^400") > y expression(7.05507910865533e+190/2.58224987808691e+120) > Eval(y) [1] 2.732144e+70 If Ryacas/Yacas cannot multiply fractions with simultaenously very large numerators and denominators, what else should I use? Thanks in advnace, Paul

Hi all, I am trying to implement the following matlab code with Ryacas : syms U x x0 C d1=diff(U/(1+exp(-(x-x0)/C)),x); pretty(d1) d2=diff(U/(1+exp(-(x-x0)/C)),x,2); pretty(d2) solx2 = solve(d2 == 0, x, 'Real', true) pretty(solx2) slope2=subs(d1,solx2) I have tried the following : library(Ryacas) x <- Sym("x");U <- Sym("U"...

Have you studied the "Introduction to Ryacas" vignette that come with the package? Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Tue, Sep 19, 2017 at 2:37 AM, Vive...

There is either something wrong with either me or is Yacas/Ryacas doing odd things. See below I ask to simpify an expression and the there's output! If this is a simplification.. well.. Do you think there is something set wrong somewhere. Thanks. > library(Ryacas) Loading required package: XML > a=Sym("a") > N=Sym("N") > b=Sym...

When I do Rcmd check Ryacas on my Windows Vista system under R version 2.6.0 beta (2007-09-23 r42958) it checks out fine but here: http://cran.r-project.org/bin/windows/contrib/checkSummaryWin.html http://cran.r-project.org/bin/windows/contrib/2.5/check/Ryacas-check.log it complains about the XML package even thou...

Hello, I am trying to construct two matrices, F and V, composed of partial derivatives and then find the eigenvalues of F*Inverse(V). I have the following equations in ryacas notation: > library(Ryacas) > FIh <- Expr("betah*Sh*Iv") > FIv <- Expr("betav*Sv*Ih") > VIh <- Expr("(muh + gamma)*Ih") > VIv <- Expr("muv*Iv") I successfully found the partial derivatives: > f11 <- deriv(FIh, "I...

Hello again. Now I have the following: > xx [1] "Solve(1 - R/100==(2*y)/10000,R)" > yacas(xx) expression(list(R == 100 * (1 - 2 * y/10000))) > I would like to put in a value for y and obtain R. I've tried more stuff with eval and Eval, but no luck yet. Any suggestions would be much appreciated. Thanks, Erin -- Erin Hodgess Associate Professor Department of Computer

Hi, To my knowledge, Ryacas can do symbolic computation in R, like Mathematica or Maple. I wonder if it (or any other R package) can solve symbolically a system of equations? I have a system of four equations in four variables (non-linear, but not very hard to solve) and wonder if Ryacas or any other package can do it. I...

...Me gustaría calcular la integral indefinida (primitiva) de una función respecto un parámetro. Al estilo de lo que hace la función D, pero al reves > s <- expression(5*x^2+2 ) > D(s,"x") 5 * (2 * x) Con integrate hay que indicar a la fuerza los límites de la integral, y con Ryacas no funciona nada, ya que no se conecta a su ip ¿Conocéis alguna forma? Saludos