similar to: Problem runnin rSymPy

Hi, can anyone tell me if R can be used to rearrange very complicated equations in terms of one of the variables? I have: dx/dt = a*b*m*y*(1-x)-r*x and, having set: dy/dx = 0, need to rearrange in terms of x. The problem I have is that I don't know how to rearrange equations when the variables are not yet defined (I get messages warning me that x etc can't be found). I'm not sure

I am experimenting with rSymPy, and it seems to work nice. However, I dislike the need to wrap all sympy expressions within quotes, it leads to ugly calls like library(rSymPy) Var("x,y,z") sympy("(x+y)**2") and so on. Inspired by the function cq from mvbutiles package: library(mvbutils) > cq function (...) { as.character(sapply(as.list(match.call(expand.dots =

Dear R Users: I would like to use symbolic integration from rSymPy and pass in the actual function. So I have > sympy("x=Symbol('x')") and if I use > sympy("integrate(cos(x),x)") it works fine. But what I want to do is something like > y <- "cos(x)" > sympy("integrate(y,x)") "cos(x)*x" Has anyone run into this, please?

Dear R People: I have been experimenting with rPython, rSymPy, and rJython. Here is my latest snag: > library(rJython) Loading required package: rJava Loading required package: rjson > library(rSymPy) > rJython <- rJython() > x <- "x" > y <- "y" > rJython$exec("from sympy import *") Error in .jcall("RJavaTools",

Dear R users, I have been using rsympy to solve a set of simultaneous equations from R. There are two solutions for the variable I'm interested in, xx[0] and xx[1], which are in terms of symbols called lam and conc. I'd like to pick out the one which is positive at (lam=0, conc=0) and call it mysol. In python I could write: if (xx[0].subs(lam,0)).subs(conc,0)>0: mysol=xx[0]

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]]

Martin (see below) gives a good explanation of the difference between AD and symbolic differentiations. I'm of the opinion we can use both. However, the real issue as far as I'm concerned (from an optimizer's point of view, which may also be that of ODE and PDE folk) is that right now none of the offerings that we have are easy to use. Indeed, usability is one of the key issues in my

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

Hi, as I find problems with yacas package... is there any R function equivalent to the yacas function "Factor" ? the factor function which i found in the R help is not the same. it doesn't factor an algebraic expression...... thanks hassan [[alternative HTML version deleted]]

Hi, I'm wondering if someone has solved the problem of converting very large integers to hex. I know about format.hexmode and as.hexmode, but these rely on integers. The numbers I'm working with are overflowing and losing precision. Here's an example: x <- "6595137340052185552" # stored as character as.integer(x) # warning about inaccurate conversion

Hi I recently gave a presentation about Automatic Differentiation (AD) and R at the Eighth Euro AD Workshop in Oxford (17/07/09). The presentation was intended as a general introduction to R and the desire for a generic AD interface for R. During the presentation I emphasised the need and the high level of interest that the R community has in developing such an interface and that input from the

Las dos Enviado desde mi iPhone > El 28/11/2013, a las 18:07, "Carlos J. Gil Bellosta " <cgb en datanalytics.com> escribió: > > ¿Numérica o simbólicamente? > > Un saludo, > > Carlos J. Gil Bellosta > http://www.datanalytics.com > > El día 28 de noviembre de 2013 18:03, jmcontreras <jmcontreras en ugr.es> escribió: >> Hola a todos

In efforts to improve optimization tools for R, one of my interests has been getting automatic differentiation capabilities so that analytic rather than numerical derivatives can be used. They would be helpful in several other areas besides optimization, My timings show factors of the order of 1000s in time improvements by avoiding numerical derivatives in some cases. There has been some work in

Hi Samba, I am sorry if this is a Newbie Question, But I am confused on what I read in the FAQ about this. What I have at the moment is a machine with Two net cards, one of which is purly a Snort interface, but due to a quirk in the OS must have a IP, the other is the network card. What would I have to put into smb.conf for samba to use only one network card? Not both as it is

Hello everybody, I'd like to use OpenSSH (client & server, for shell & sftp) on an embedded PC with limited resources (processor 386 SX 40Mhz 8Mb RAM). I have Linux running on it. In the past, I tried to use OpenSSH on it just to see if it could work but each connection required an incredible long time to start. I suppose that the key generation is too expensive for that processor.

Samba team, I posted the following message on May 30 to comp.protocols.smb, but no one has responded to the posting as of yet, so I thought I'd try this email list. We are testing winbind and security=domain to authenticate NT users on our UNIX box in samba (v2.2.3a). Winbind is working correctly. Wbinfo shows users as domainname+username (we are using "+" as the

Hello, I am a new R user, using version 1.5.1. I am attempting to run R programs from a dos command line (in win2000) and am having problems. My goal is to be able to use R from batch scripts in both windows and also in Linux eventually later. When I first ran "rcmd BATCH --help" it said that perl was not found. after installing perl and running again, I received the following error:

On Wed, Feb 25, 2009 at 10:26:02AM -0800, Chris Lattner wrote: > > On Feb 24, 2009, at 10:03 PM, Julien Lerouge wrote: > > > On Tue, Feb 24, 2009 at 06:24:17PM -0800, Julien Lerouge wrote: > >> I haven't tested with objdir != srcdir. > > > > Ok, that was broken. Attached is a smaller diff that should work in > > all > > cases. > > This

On Feb 24, 2009, at 10:03 PM, Julien Lerouge wrote: > On Tue, Feb 24, 2009 at 06:24:17PM -0800, Julien Lerouge wrote: >> I haven't tested with objdir != srcdir. > > Ok, that was broken. Attached is a smaller diff that should work in > all > cases. This sounds really cool Julien! Two questions: 1) does it preserve the checking that the existing tcl stuff does, which

2009/8/30 Uwe Ligges <ligges at statistik.tu-dortmund.de>: [snip] > Guido van Steen wrote: [snip] >> Something that interests me too: What about R's policy with respect to >> including binary files? I saw that developers should include a file [snip] > Please do not include binary files and carefully watch for licenses of those > files (e.g. if GPL'ed, you need to