search for: bbsolve

Dear Dr. Gilbert, Dr. Varadhan and all R-help list members, I'm using the function BBsolve( ) and I have some questions on the stopping criterion "maxit" and "noimp" specified in the option "control". Here are two such examples I'm having problem with. In these two examples, the function BBsolve( ) always stops at iteration 100, overlooking the va...

Hi r-users, I would like to solve system of nonlinear equation using BBsolve function and below is my code.  I have 4 parameters and I have 4 eqns. mgf_gammasum <- function(p) { t  <- rep(NA, length(p)) mn <- 142.36 vr <- 9335.69 sk <- 0.8139635 kur <- 3.252591 rh  <- 0.896 # cumulants k1 <- p[1]*(p[2]+p[3]) k2 <- p[1]*(2*p[2]*p[3]*p[4] +p[2]^2+...

Dear: I am having trouble solving simultaneous nonlinear equations by R. I have been using BBsolve (BB) to do so. Though the function is very strong, still the program doesn't converge. I have tried all (according to my small knowledge) the options described in the help file. Now I am trying to find something else than BBsolve for solving simultaneous nonlinear equations by R. Any idea or s...

Dear All, I need to find the (possible multiple) zeros of a function f within an interval. I gave uniroot a try, but it just returns one zero and I need to provide it with an interval [a,b] such that f(a)f(b)<0. Is there any function to find the multiple zeros of f in (a,b) without constraints on the sign of f(a) and f(b)? Many thanks Lorenzo

...tion, my program works but sometimes give error message regarding some "built-in function" which I never used in my code. I have no idea about the problem. Any suggestion, comments or idea regarding this would be highly appreciable. Thanks. I have used ---- "maxLik()" and "BBsolve()" in my code. Error message shows regarding "optim()". Best regards. -- Rajibul Mian Grad Student, Maths & STATS, UWindsor, Canada. https://sites.google.com/site/rajibulmian/ [[alternative HTML version deleted]]

...e next step (H = step size). Solver will continue anyway. In above, R1 = 0.2630651367072D+01 R2 = 0.2055665829864D-15 .... Error in optim(par = par, fn = U, method = "Nelder-Mead", control = list(maxit = 100), : function cannot be evaluated at initial parameters ... Error in BBsolve(par = par, fn = Bo, s = s, outmat = outmat, method = c(1, : object 'ans.best' not found In addition: Warning messages: 1: In lsoda(y, times, func, parms, ...) : an excessive amount of work (> maxsteps ) was done, but integration was not successful - increase maxsteps 2: In lsoda(y, t...

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, I would appreciate if someone could help me on track with this problem. I want to compute some parameters from a system of equations given a number of sample observations. The system looks like this: sum_i( A+b_i>0 & A+b_i>C+d_i) = x sum_i( C+d_i>0 & C+d_i>A+b_i) = y sum_i( exp(E+f_i) * ( A+b_i>0 & A+b_i>C+d_i) = z A, C, E are free variables while the other

Hello there, I wish to solve the following nonlinear System of equations: + u1 - Vmax11*S1/(S1 + Km11 *(1 + S2/Km21)) - Vmax12*S1/( S1 + Km12 *(1+S2/Km22)) == 0 + u2 - Vmax22*S2/(S2 + Km22 *(1 + S1/Km12)) - Vmax21*S2/( S2 + Km21 *(1+S1/Km11)) == 0 + Vmax11*S1/(S1 + Km11 *(1 + S2/Km21)) + Vmax12*S1/( S1 + Km12 *(1+S2/Km22)) - d1*P1 == 0 + Vmax22*S2/(S2 + Km22 *(1 + S1/Km12)) + Vmax21*S2/( S2 +

Hi, Is this method broken in R? I am using it to find roots of the following function: f(x) = 2.5*exp(-0.5*(2*0.045 - x)) + 2.5*exp(-0.045) + 2.5*exp(-1.5*x) - 100 It is giving an answer of -38.4762403 which is not even close (f(x) = 2.903809e+25 for x=-38.4762403). The answer should be around 0.01-0.1. This function should converge.. Even for a simple function like f(x) = exp(-x) * x, it gives

...?summaryRprof running at 100% cpu for one hour ... (Kjetil Halvorsen) 33. Re: An empty grey diagram (Martin Maechler) 34. Re: ?summaryRprof running at 100% cpu for one hour ... (Mike Marchywka) 35. Re: Check for is.object (Jonathan P Daily) 36. Re: solve nonlinear equation using BBsolve (Berend Hasselman) 37. Re: Alternatives to image(...) and filled.contour(...) for 2-D filled Plots (Ista Zahn) 38. Re: statistical test for comparison of two classifications (nominal) (Matt Shotwell) 39. Re: Check for is.object (Phil Spector) 40. Re: "negative alpha" o...