similar to: Is there a facility in R similar to MatLab "syms" that allows using unevaluated numeric symbols in matrices?

I needed a symbolic and algebraic computation software. The best solution I've found so far is maxima computer algebra system. I was wondering if there is any R package that has similar features as maxima's or somebody could point me to reference manuals on how to use R for this purpose. Thanks, Angel

Is possible to integrate this diferential equation: dN/dt = Nr(1-(N/K)) in R using the integrate() function? Or any other diferential equation? If yes, how? If no, anybody know any software on linux that make this? Inte Ronaldo -- O problema de ter os dois p??s bem firmes no ch??o ?? que voc?? n??o vai conseguir tirar as cal??as. --An??nimo -- |> // | \\

I am working on a project that requires me to do very large factorial evaluations. On R the built in factorial function and the one I created both are not able to do factorials over 170. The first gives an error and mine return Inf. Is there a way to have R do these larger calculations (the calculator in accessories can do 10000 factorial and Maple can do even larger) -- View this message in

Hello Does anybody know how one can compute d largest eigenvalues/eigenvectors in R, like in MATLAB eigs function ? eigen function computes all eigenvectors/eigenvalues, and they are slightly different than those generated by matlab eigs. Thanks in advance -- View this message in context: http://www.nabble.com/matlab-eigs-function-in-R-tp17619641p17619641.html Sent from the R help mailing list

Hi, I'm trying to get ...as a list of unevaluated arguments, ie. substitute(list(...)) gives me an unevaluated list of the arguments, but I want a list of the unevaluated arguments. My attempts so far: (function(...) substitute(...))(a=1, b=a) # Only returns first (function(...) substitute(list(...)))(a=1, b=a) # Unevaluated list, not list of unevaluated (function(...)

Hi, I was wondering if anyone knew of an implementation of a function similar to "eigs" in Matlab (full description here: http://www.mathworks.com/access/helpdesk/help/techdoc/ref/eigs.html). This function differs from the standard "eigen" in that it computes a *few* eigenvectors for cases in which your matrix is very large and/or you don't need all the eigenvectors.

Hi all, Is there any other packages to do numerical integration other than the default 'integrate'? Basically, I am integrating: integrate(function(x) dnorm(x,mu,sigma)/(1+exp(-x)),-Inf,Inf)$value The integration is ok provided sigma is >0. However, when mu=-1.645074 and sigma=17535.26 It stopped working. On the other hand, Maple gives me a value of 0.5005299403. It is an

Hi, How to turn a character string into an unevaluated R object? I want to load some files in a directory into data matrix R objects. I could do this with read.table and assign (see below). Then, I want to turn the character string representing a file name (the evaluated expression of i) into an unevaluated R object. Basically, I want to create matrices whose names are the same as the related file

Hi R-users, I would like to create an expression without evaluating it. Then paste that expression to an object. Example: Result <- paste('Result', 1, sep="") paste(Result, substitute(apply(exp.des[1:10,], 1, one.row, parms=parameters)), sep="<-") However this pastes EACH element of the unevaluated expression. Instead I just would like the expression

Hello, x<- "something(a+b) + c" is there any function F such that F(x) gives me the unevaluated value of x, i.e. something(a+b)+c I would appreciate any help on this thanks --------------------------------- [[alternative HTML version deleted]]

HI, As I'm trying to compute Taylor series, I'm having problems in adding and multiplying unevaluated expressions. I searched for a solution but found none. my Taylor function works fine for evaluating functions as you can see here: rTaylorVal=function(exp,x0,dx,n) { ls=list(x=x0) newexp=eval(exp,ls) exp0=exp for (i in 1:n){ exp0=D(exp0,"x")

-------- Original-Nachricht -------- Betreff: Re: [R] Adding and Multiplying two Unevaluated Expressions Datum: Tue, 01 Dec 2009 23:49:39 +0100 Von: Benjamin M?ller <ben_mueller.bm at web.de> An: Rolf Turner <r.turner at auckland.ac.nz> Referenzen: <20091201144125.316310 at gmx.net> <8E40E49F-E8FC-4FBD-8CC5-93789FFB0E53 at auckland.ac.nz> This works fine for your

Hi, I have just seen Stefan Steinhaus' web page : http://www.uni-franfurt.de/~stst/ncrunch.html I think it would be nice to include "R" as well. I have taken Forrest Young's email on stat-lisp list and changed the stuff for "R" :) Here it is: (someone please check this so we can also send it to Stefan Steinhaus.

Dear R-listers Is there anyone who knows why I get different eigenvectors when I run MatLab and R? I run both programs in Windows Me. Can I make R to produce the same vectors as MatLab? #R Matrix PA9900<-c(11/24 ,10/53 ,0/1 ,0/1 ,29/43 ,1/24 ,27/53 ,0/1 ,0/1 ,13/43 ,14/24 ,178/53 ,146/244 ,17/23 ,15/43 ,2/24 ,4/53 ,0/1 ,2/23 ,2/43 ,4/24 ,58/53 ,26/244 ,0/1 ,5/43) #R-syntax

Hi Folks, I am using Windows 2000 and was wondering what (Open Source) software R users use or might recommend for symbolic computations (aside from the ol' noggin, e.g., Maxima, Mathomatic) . Thanks, Hank Dr. Martin Henry H. Stevens, Assistant Professor 338 Pearson Hall Botany Department Miami University Oxford, OH 45056 Office: (513) 529-4206 Lab: (513) 529-4262 FAX: (513) 529-4243

Hi there, I have data frame with columns ID and Date. There are multiple rows for each ID, but I only want to keep the *first* such row--i.e., the row corresponding to the earliest event. So if I had, say, 1000 rows of 100 IDs doing an average of ten events each, I'd run this trimming procedure and end up with a data frame containing 100 rows (one for each ID), where each row record that

Hi there, Suppose the cmd is "a<-3", I can parse the cmd sexp with R_ParseVector and eval it. My question is - is it possible to parse a cmd like "a <- ?", afterwards evaluation will give corresponding result depend on different argument? In other words, '?' is just a placeholder. Thanks. Xin [[alternative HTML version deleted]]

Given the extremely simple package at https://github.com/jimhester/testUnload, which includes only one S3 method 'print.object' the following code produces a lazy load error from a new R session (R-devel r69801) install.packages("testUnload", repos = NULL) library("testUnload") unloadNamespace("testUnload") install.packages("testUnload", repos =

Hi, Consider the following (much simplified) Sweave example: -------------- First, we set the value of $x$: <<chunk1,eval=FALSE>>= x <- 1 @ Then we set the value of $y$: <<chunk2,eval=FALSE>>= y <- 2 @ Thus, the overall algorithm has this structure: <<combined,eval=FALSE>>= <<chunk1>> <<chunk2>> @

Thanks to Deepayan Sarkar (lattice) and Paul Murrell (grid) I have nearly finished porting the Hmisc library's xYplot function to R. xYplot extends xyplot to allow for error bars, bands, and a few other features. In S-Plus I extended the Trellis function xyplot mainly by writing panel.xYplot. In R, xyplot contains a lot of code, so I implemented xYplot by calling xyplot from it. Things are