similar to: newbie needs help using R as solver

I was playing around with a simple example using solve.qp ( function is in the quadprog package ) and the code is below. ( I'm not even sure there if there is a reasonable solution because I made the problem up ). But, when I try to use solve.QP to solve it, I get the error that D in the quadratic function is not positive definite. This is because Dmat is zero because I don't have a

Hi. I am aware of three different R packages for linear programming: glpk, linprog, lpSolve. From what I can tell, if there are N variables and M constraints, all these solvers require the full NxM constraint matrix. Some linear solvers I know of (not in R) have a sparse matrix input format. Are there any linear solvers in R that have a sparse matrix input format? (including the

Dear all is there any linear programming routine available for R? if not, can you suggest any alternatives? not need to be very powerful, I get only a samll problem to resolve. many thanks yong

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 -- |> // | \\

Just thought I'd ask. For those who've never seen TK!Solver, I strongly recommend taking a look. So far as I can tell, it's the only product of its type available, retail or open source, for any platform. What makes TK!Solver so cool is that it adaptively back-solves pretty much any unknown from any set of equations you give it. (or vector full of unknowns, producing a vector of

Just wondering if there's an R package which does tricks similar to what TK!Solver does. TK!Solver, for those not lucky enough to have found it, basically allows one to define a bunch of equations, assign values to an arbitrary subset of the variables, from which it calculates (either directly when possible or back-solving when not) the values of the other variable(s). thanks Carl

Hi, I can't seem to get any Excel Add-Ins to work. In particular, I need the 'Solver' for an assignment ... I've tried with two office versions (2007/2003), which I've managed to install successfully (you have to enable the Solver add-in during installation), but it's the same every time. When I try to start it up I get a message saying can't access SOLVER.XLA, and

hi.. i used R a few days.. who can call me? same function solver in excel. _________________________________________________________________ [[elided Hotmail spam]] [[alternative HTML version deleted]]

Dear guys, I've put the puzzle solver running on LLVM 2.1. Well, at least partially, for it is failing three of SPEC2000 benchmarks. I will try to debug it now. The results are not as good as before. I mean, the puzzle solver is still the same, but the default allocator is producing very good code now. Even though, the puzzle solver produces faster code for half the benchmarks. It

This is applicable to either using optim or the differential equation solver or any similar solver Suppose I want to use the differential equation solver and this is my code d<-y[2] vdpol<-function(t,y) { list(c(1, d, 3, 4 ) } stiff<-ode(y=rep(0,4),times=c(0,1),func=dvdpol,parms=1) The thing is I want d to be composed of one of state variables in the

Hi all, i'm trying to find a solver possibility analogous to the Excel Solver in R. Since i just started with R, I have only little knowledge. Can someone help me by solving the problem? I have the following 'starting position': z = rnorm(1,0,1) y <- function(x,z){2*x - 1 + z} I am looking for a certain "x" in such a way that the result of the function 'y'

Hello -- The question I have is about the gmm() function from the 'gmm' package (v. 1.4-5). The manual accompanying the package says that the gmm() function is programmed to use either of four numerical solvers -- optim, optimize, constrOptim, or nlminb -- for the minimization of the GMM objective function. I wonder whether there is a way to pass controls to a solver used while calling

Hi all: I'm looking for a package that similar to solver in MS. All I need is find a r to satisfy R0=sum( r * Xt ), where t are from 1 to n and Xt are come from another formula. The most package I found were to max or min the obj. function. Is there any package can do it? Thanks. Peter [[alternative HTML version deleted]]

Hi all, Earlier today I posted this question on s-news, so apologies to some for the duplication. > Please put aside your snobbery about Microsoft products for a moment. > > I am fitting population models to annual survey data for trout. For those of you familiar with ecological models, I am working in the Lefkovitch matrix framework; for those unfamiliar with that shorthand, the

Esteemed colleagues I wonder if there is a package in R that performs the functions of the Excel SOLVER. Thanks in advance for the reply. Best regards, ------------------------- Estimados colegas Me pregunto si hay un paquete en R que funcione como el SOLVER de Excel. De antemano gracias por la respuesta. Saludos, -- Ricardo Bandin Llanos rbandin@udec.cl [c] Magíster Cs. m. Pesquerías

Hi, I'm Pina and I'm a student in geology. I'm working with spectral profile of sand and I have to find the similarity between one spectral profile selected by hyperspectral image anche one that I created to mix different percentage of 4 mineral component. I have to find the best mix of percentage of this 4 mineral in order to have the best likeness with the spectral profile chose by

I am trying to use the package ode and periodically it will come up with this error message Warning..Internal T (=R1) and H (=R2) are such that in the machine, T + H = T on the next step (H = step size). Solver will continue anyway. And then the program just take very long to run. Is there anyway to get the program to terminate when this warning is issued instead of continuing to run ?

Hello, for my diploma thesis I need to program a solver for Merton?s respectively Black?s and Scholes? Option pricing formula, which should be achieved for several dates. What I want to do is to estimate the value of a firm?s assets "vA" (x[2] denotes vA) and the option-implied volatility of firm?s assets "sigA" (x[1] denotes sigA) by solving it simultaneous using the Black

Dear All, I was using rk4 and lsoda to solve a ODE system. However, both of them gave bad accurate solutions, especially compared with Matlab solver ODE45. For example, ODE45 gave solutions that can go to a stable level (about 1.6) when time goes to infinity, however, the solutions from lsoda are decreasing to very very small (about 1e-130) numbers. Does R have more accurate ODE solvers as

Dear all, I am trying to find the solution for the optimization problem focused on the finding minimum cost. I used the solution proposed by excel solver, but there is a restriction in the number of variables. My data consists of 300 rows represent cities and 6 columns represent the centres. It constitutes a cost matrix, where the cost are distances between each city and each of six centres. ..+