Displaying 20 results from an estimated 10000 matches similar to: "Wait for keystroke or timeout"
2009 Oct 22
2
Advice on how to arrange fix of buglet
Recently I reported a small bug in optim's SANN method failing to report
that it had exceeded the maximum function evaluation limit in the
convergence code. This is a small enough matter that I was reluctant to
create a full-blown bug report. Indeed in the optimx package Ravi
Varadhan and I have been developing on r-forge (under the OptimizeR
project) it was a minimal work around to fix
2010 Nov 16
4
DBLEPR?
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
2010 Nov 16
4
DBLEPR?
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
2017 Nov 10
3
update R version in windows
However, trying this on Linux Mint gave
package ?installr? is not available (for R version 3.4.2)
Has the package not been updated yet?
JN
Try the installr package. It was designed for this purpose.
On Fri, Nov 10, 2017 at 11:49 AM, Bond, Stephen <Stephen.Bond at cibc.com> wrote:
> Is there a utility which will allow me to upgrade my R version and update all packages from the old
2010 Nov 30
5
Minor warning about seq
I spent more time than I should have debugging a script because I wanted
x<-seq(0,100)*0.1
but typed
x<-seq(O:100)*0.1
seq(0:100) yields 1 to 101,
Clearly my own brain to fingers fumble, but possibly one others may want to avoid it.
JN
2015 Apr 25
2
Title case in DESCRIPTION for package where a word is a function namei
> 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
2015 Jan 18
3
Help finding source of warnings
I've been implementing a wrapper to the 2011 Fortran version of
L-BFGS-B. In optim(), R uses a C translation of a Fortran version (the
version number does not appear to be documented by the original
authors). The authors of the original Fortran code have updated it and
published the reasons in ACM TOMS due to inefficiencies and a bug.
In running the checks on the resulting package (which
2012 Apr 28
2
Character string to R object
I've been creating some R tools that manipulate objective functions for optimization. In
so doing, I create a character string with R code, and then want to have it in my
workspace. Currently -- and this works fine -- I write the code out, then use source() to
bring it in again. Example:
cstr<-"jack<-function(x){\n cat(\"Silly x:\")\n print(x) \n }\n"
write(cstr,
2011 Aug 17
2
An example of very slow computation
This message is about a curious difference in timing between two ways of computing the
same function. One uses expm, so is expected to be a bit slower, but "a bit" turned out to
be a factor of >1000. The code is below. We would be grateful if anyone can point out any
egregious bad practice in our code, or enlighten us on why one approach is so much slower
than the other. The problem
2009 Jul 30
3
R User Group listings
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
2009 Dec 06
5
optim with constraints
Hi, dear R users
I am a newbie in R and I wantto use the method of meximum likelihood
to fit a Weibull distribution to my survival data. I use "optim" as
follows:
optim(c(1, 0.25),weibull.like,mydata=mydata,method="L-BFGS-B",hessian
= TRUE)
My question is: how do I setup the constraints so that the two
parametrs of Weibull to be pisotive? Or should I use other function
2015 Apr 24
3
Title case in DESCRIPTION for package where a word is a function name
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
2017 Aug 22
3
How to benchmark speed of load/readRDS correctly
Not convinced Jeff is completely right about this not concerning R, since I've found that the application language (R,
perl, etc.) makes a difference in how files are accessed by/to OS. He is certainly correct that OS (and versions) are
where the actual reading and writing happens, but sometimes the call to those can be inefficient. (Sorry, I've not got
examples specifically for file
2009 Sep 14
2
Escaping . in regular expression
If I run
cvec<-c("test.f", "test.sf", "try.g","try.res", "try.f")
print(cvec)
indx<-grep('\.f',cvec,perl=TRUE)
fset<-cvec[indx]
print(fset)
I get
> cvec<-c("test.f", "test.sf", "try.g","try.res", "try.f")
> print(cvec)
[1] "test.f" "test.sf"
2012 Mar 01
3
Converting a string vector with names to a numeric vector with names
Not paying close attention to detail, I entered the equivalent of
pstr<-c("b1=200", "b2=50", "b3=0.3")
when what I wanted was
pnum<-c(b1=200, b2=50, b3=0.3)
There was a list thread in 2010 that shows how to deal with un-named vectors, but the same
lapply solution doesn't seem to work here i.e.,
pnum<-lapply(pstr, as.numeric)
or similar vapply
2020 May 08
2
Xenial repository for R 4.0.0
Over a week ago (on r-help, my bad!) I raised a question of why the
ubuntu install instructions
https://cran.r-project.org/bin/linux/ubuntu/README.html
instruct users with a xenial-based system to use
deb https://cloud.r-project.org/bin/linux/ubuntu xenial-cran40/
Looking at https://cloud.r-project.org/bin/linux/ubuntu/
there is no xenial-cran40 directory. However,
2020 Mar 26
2
unstable corner of parameter space for qbeta?
Despite the need to focus on pbeta, I'm still willing to put in some effort.
But I find it really helps to have 2-3 others involved, since the questions back
and forth keep matters moving forward. Volunteers?
Thanks to Martin for detailed comments.
JN
On 2020-03-26 10:34 a.m., Martin Maechler wrote:
>>>>>> J C Nash
>>>>>> on Thu, 26 Mar 2020
2010 Mar 10
1
R CMD check issue with soft-linked directory
I've been having some strange problems with R CMD check in the last couple of days, but
now believe I have localized the issue.
I had been running Ubuntu Hardy on one drive and then upgraded to Jaunty, but put Jaunty
on a different drive. I continue to be able to boot Hardy when I wish. I soft-linked my R
working area i.e.,
/home/john/Rstuff ----> /media/lnx804/home/john/Rstuff
2019 Mar 04
2
Package inclusion in R core implementation
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 (optim::L-BFGS-B, nlm, nlminb) can and should be moved to
packages (there are already 2 versions at least of LBFGS
2023 Aug 20
1
Determining Starting Values for Model Parameters in Nonlinear Regression
The cautions people have given about starting values are worth heeding. That nlxb() does well in many cases is useful,
but not foolproof. And John Fox has shown that the problem can be tackled very simply too.
Best, JN
On 2023-08-19 18:42, Paul Bernal wrote:
> Thank you so much Dr. Nash, I truly appreciate your kind and valuable contribution.
>
> Cheers,
> Paul
>
> El El