similar to: Restricting optimisation algorithm's parameter space

Hello, I have a problem. I am using the NLME library to fit a non-linear model. There is a linear component to the model that has a couple parameter values that can only be positive (the coefficients are embedded in a sqrt). When I try and fit the model to data the search algorithm tries to see if a negative value for one of these parameter values will produce an optimal fit. When it does

Dear R users I have tried to install the optimx but met problems. I have gone to the website you suggested: https://r-forge.r-project.org/R/?group_id=395 and tried to install it with the following method: install.packages("optimx", repos="http://R-Forge.R-project.org") I have received the following information: package 'numDeriv' successfully unpacked and MD5

I'll not be able to comment on the use of C like this, but will warn that I wrote the routines that became Nelder-Mead, CG, and BFGS in optim() in the mid 1970s. CG never did as well as I would like, but the other two routines turned out pretty well. However, in nearly 40 years, there are a few improvements, particularly in handling bounds and masks (fixed parameters). For all-R routines see

While lm() is a linear modeling, the constraints make it easier to solve with a nonlinear tool. Both my packages Rvmmin and Rcgmin (I recommend the R-forge versions as more up-to-date) have bounds constraints and "masks" i.e., fixed parameters. I am actually looking for example problems of this type that are more recent than the ones that got me into this 30 years ago. Do contact me

I have not included the previous postings because they came out very strangely on my mail reader. However, the question concerned the choice of minimizer for the zeroinfl() function, which apparently allows any of the current 6 methods of optim() for this purpose. The original poster wanted to use Newton-Raphson. Newton-Raphson (or just Newton for simplicity) is commonly thought to be the

Hi Spencer: See the link below about L-BFGS-B below because I had problems with it a good while back (and I think the link description is the cause but I can't prove it ) so eventually I moved to the Rvmmin(b) package. It's a package but really an algorithm. Rvmmin(b) uses a variable-metric algorithm similar to that of L-BFGS-B but without the problem below. It's not surprisingly a

Hi, Mark et al.: Thanks, Mark. Three comments: 1. Rvmmin was one of the methods I tried after Ravi directed me to optimx. It returned NAs for essentially everything. See my email of this subject stamped 4:43 PM Central time = 21:43 UTC. 2. It would be interesting to know if the current algorithm behind optim and optimx with

Hello: The development version of Ecdat on R-Forge contains a vignette in which optim(?, method=?L-BFGS-B?) stops with an error message while violating the lower bound. To see all the details, try the following: install.packages("Ecdat", repos="http://R-Forge.R-project.org") Then do "help(pac=Ecdat)" -> "User guides, package

Hi, I just installed the odesolve package and ran the check command on it. It failed trying to execute library(gnlm). Sure enough, there is no gnlm library on my system and I could not find it on the CRAN archive either. Am I missing anything obvious or is gnlm some private library that somehow found its way into the example section of odesolve? Thanks in advance, Andy

Pursing my earlier question, when I tried loading Lindsey's gnlm, I got a message Loading required package: rmutil Warning message: There is no package called 'rmutil' in: library(package, character.only = TRUE, logical = TRUE, warn.conflicts = warn.conflicts, According to the R documentation http://finzi.psych.upenn.edu/R/doc/html/packages.html rmutil is in the standard

I've been trying to prepare some wrappers for optimization objective functions and gradients that use try() to check for computable functions. I'm also trying to do scaling as per optim() so that a number of methods that are available on CRAN and R-Forge can use parameter and function scaling. This got me into minor trouble when I scaled a gradient or Hessian and the

I just had a memory crash with R-0.64.1. I am running under intel pentium 200mhz under slackware linux 2.0.30. 1/home/plindsey >gdb /usr/local/src/R/bin/R.binary core GDB is free software and you are welcome to distribute copies of it under certain conditions; type "show copying" to see the conditions. There is absolutely no warranty for GDB; type "show warranty" for

Hi, I'm not yet familar with GLM and still learning. How can I perform a BNL (to estimate LDp values) with matrixes like this (N indicates the observed objects): data from: Kerr D, Meador J. 1996. "Modeling Dose Response Using Generalized Linear Models". Environ Toxicol Chem 15(3) conc respond n 0 0 20 0 1 19 0 1 20 0 0 20 13.5 5 23 13.5 2 20 29 9 20 29 6 20 53 12 20 53 15 20 85

Hi, I would like to write a function that finds parameters of a log-normal distribution with a 1-alpha CI of (x_lcl, x_ucl): However, I don't know how to optimize for the two unknown parameters. Here is my unsuccessful attempt to find a lognormal distribution with a 90%CI of 1,20: prior <- function(x_lcl, x_ucl, alpha, mean, var) { a <- (plnorm(x_lcl, mean, var) - (alpha/2))^2 b

Dear R users and developers, Due to a failure of the electrical system, the IT services (also hosting R-project related websites) of the WU (Vienna University of Economics and Business) are currently unavailable. Affected websites and services are: CRAN master (cran.r-project.org), the R-project website (www.r-project.org) and R-Forge (r-forge.r-project.org). The R binaries and sources as

Dear R users and developers, Due to a failure of the electrical system, the IT services (also hosting R-project related websites) of the WU (Vienna University of Economics and Business) are currently unavailable. Affected websites and services are: CRAN master (cran.r-project.org), the R-project website (www.r-project.org) and R-Forge (r-forge.r-project.org). The R binaries and sources as

A tangential email discussion with Simon U. has highlighted a long-standing matter that some tools in the base R distribution are outdated, but that so many examples and other tools may use them that they cannot be deprecated. The examples that I am most familiar with concern optimization and nonlinear least squares, but other workers will surely be able to suggest cases elsewhere. I was the

Hello R users, Doing My PhD I collected count data which I believe is zero inflated. I have run a statistical model with lmer and family=poisson and got summary(model)@sigma=1 so I believe there is no overdispertion. I would like to use the fmr function from the 'gnlm' library but I just cannot figure out from the examples in the help page and some forums out there how to convert the lmer

Dear list, The task view on optimization does not reference a package for non linear constrained optimization problems. Stefan Theussl told me to look at the Rsolnp package, but unfortunately it is not very clear what method is R ported. (The authors ported the matlab code of Yinyu Ye http://www.stanford.edu/~yyye/ <http://www.stanford.edu/%7Eyyye/>) Currently I'm looking for an

Hi, As you probably know, there is a problem with the interface for adding uniform random number generators in R (see by article in R News 5/2, November 2005). There exists a mechanism called "user-supplied" that allows users of R to run their own generator in R. However, there is no such mechanism for package writers. Those who want to add their own generators abuse