similar to: optimization with bounds on parameters

>>>>> Duncan Murdoch >>>>> on Sun, 26 Mar 2023 12:41:03 -0400 writes: > On 26/03/2023 11:54 a.m., J C Nash wrote: >> 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 base R distribution are outdated, but that so many 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

I'm planning to try to use Mike Powell's new BOBYQA optimization routine to see if it is a good candidate to eventually replace Nelder-Mead as the optim() default. (Don't panic -- this won't happen quickly.) Mike writes f77 code. After some chasing about, I've realized that because optimization codes need to call the objective function written in R, they need to use a language

Hi, I'm new to R, and I'm not a statistician (stunned silence). I am trying to do the following: 1. read in a 2-column data file, e.g. status new db green title "Most Significant Excursions" 2. end up with an R list such that I can write e.g. lst$title and have R return "Most Significant Excursions". I know I could do this by coding lst = list(title="Most

This patch adds new control messages for vcpu hotplug events. Via the xm vcpu_hotplug sub-program, VCPUS in domains can be enabled/disabled when CONFIG_HOTPLUG_CPU is enabled in the target domain''s kernel. Currently there is nothing that tracks whether a VCPU is up or down. My previous [1]patch added a new per-VCPU flag (VCPUF_down) which could be used to keep track of which VCPUS are

On Mon, Mar 4, 2019 at 5:01 PM J C Nash <profjcnash at gmail.com> wrote: > As the original coder (in mid 1970s) of BFGS, CG and Nelder-Mead in > optim(), I've > been pushing for some time for their deprecation. They aren't "bad", but > we have > better tools, and they are in CRAN packages. Similarly, I believe other > optimization > tools in the core

> On 25 Apr 2015, at 13:11 , Prof J C Nash (U30A) <nashjc at uottawa.ca> wrote: > > Hendrik pointed out it was the parentheses that gave the complaint. > Single quotes and no parentheses seem to satisfy R CMD check. Perhaps > that needs to be in the WRE. Well, it is in ?toTitleCase: ...However, unknown technical terms will be capitalized unless they are single

There are now several R geographic user groups, and a few have mailing lists on the R mailing list system. Thanks to Martin M, there's also a pointer to a page I'm maintaining to list/describe the groups. The page is at http://macnash.telfer.uottawa.ca/RUG.html Contact me if you have a listing. I'm prepared to wikify it if there is sufficient interest. John Nash

Full_Name: David D Degras Version: 2.8.0 OS: Mac OS X Submission from: (NULL) (128.135.239.11) I have recently installed the version 2.8.0 of R along with package fda (v 2.0.2) and its dependencies (including package splines v. 2.8.0). Here are my problems: 1) The package splines should feature functions such a predict.bs, predict.bSpline and such and it does not! I can make calls to bs, ns,

I concur with Avraham that capabilities need to be ensured e.g., in recommended packages. I should have mentioned that. My concern is that the core should be focused on the programming language aspects. The computational math and some of the more intricate data management could better be handled by folk outside the core. JN On 2019-03-04 9:12 a.m., Avraham Adler wrote: > On Mon, Mar 4, 2019

On 24.04.2015 22:44, Ben Bolker wrote: > Prof J C Nash (U30A <nashjc <at> uottawa.ca> writes: > >> >> I was preparing a fix for a minor glitch in my optimx package and R CMD >> check gave an error that the title was not in title case. > > [snip] to make Gmane happy ... > >> I have found >> >> A Replacement and Extension of the

predict.warn() -- a function to display factor levels in new data for linear model prediction that do not exist in the estimating data. Date: 2005-8-24 From: John C. Nash (with thanks to Uwe Ligges for suggestions) nashjc at uottawa.ca Motivation: In computing predictions from a linear model using factors, it is possible to introduce new factor levels. This was encountered on a practical

How about allowing underscore? (I believe WRE is silent on this, and I have not tried submitting a package with underscore in the title.) As I pointed out in my OP, _optim()_ works. And we have the advantage that we can distinguish package from function. The purpose of consistent editing is surely to provide the affordances that save us from needing extra documentation, as per Donald Norman's

Dear R-er, For a non-linear optimisation, I used optim() with BFGS method but it stopped regularly before to reach a true mimimum. It was not a problem with limit of iterations, just a local minimum. I was able sometimes to reach better minimum using several rounds of optim(). Then I moved to optimx() to do the different optim rounds automatically using "Nelder-Mead" and

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+p[3]^2) k3 <-

Ravi Varadhan and I have been looking at UCMINF to try to identify why it gives occasional (but not reproducible) errors, seemingly on Windows only. There is some suspicion that its use of DBLEPR for finessing the Fortran WRITE() statements may be to blame. While I can find DBLEPR in Venables and Ripley, it doesn't get much mention after about 2000 in the archives, though it is in the R FAQ

Ravi Varadhan and I have been looking at UCMINF to try to identify why it gives occasional (but not reproducible) errors, seemingly on Windows only. There is some suspicion that its use of DBLEPR for finessing the Fortran WRITE() statements may be to blame. While I can find DBLEPR in Venables and Ripley, it doesn't get much mention after about 2000 in the archives, though it is in the R FAQ

Hi, I have written an R translation of C.T. Kelley's Matlab version of the Nelder-Mead algorithm. This algorithm is discussed in detail in his book "Iterative methods for optimization" (SIAM 1999, Chapter 8). I have tested this relatively extensively on a number of smooth and non-smooth problems. It performs well, in general, and it almost always outperforms optim's

Chandler Carruth <chandlerc at google.com> writes: > The overwhelming majority of contributors and users of trunk seem to > be fine with this, so while I'm interested in anything we can do to > make it easier for you, unless we see significantly more concerns > about this plan, I think we should move forward. > > Fundamentally, we aren't going to be able to make

Hi, I Emailed this afternoon that bwlimit leads to a much too low bwlimit if small amounts of data are sent in each write. I wrote a small patch now. Congrats on the code: It's nice and clean: I wrote a working patch in 5 minutes after examining a total of 25 lines of code. (My backup used to require two hours of small sleeps alone, which should be reduced by a factor of 8....)

On Tue, Nov 5, 2013 at 10:12 AM, <dag at cray.com> wrote: > Chandler Carruth <chandlerc at google.com> writes: > > So far, I'm not hearing any significant objections. > > > > I'm going to put the plan of record about this into the release notes, > > and I'll write up a blog post about it and do some other things which > > will likely make