Re: [Rd] feature request: optim() iteration of functions that return multiple values
For a solution that does not require any change to the original function
being optimized, the following one-liner could be used, which converts
existing functions to functions that return only the first element:
returnFirst <- function(fun) function(...) do.call(fun,list(...))[[1]]
Example:
fr <- function(x) { ## Rosenbrock Banana function
x1 <- x[1]
x2 <- x[2]
ans <- 100 * (x2 - x1 * x1)^2 + (1 - x1)^2
list(ans=ans, extra1 = 1:10, extra2 = letters)
}
fr2 <- returnFirst(fr)
tmp <- optim(c(-1.2,1), fr2)
fr(tmp$par)
Am 03.08.23 um 22:21 schrieb Sami Tuomivaara:
Dear all,
I have used optim a lot in contexts where it would useful to be able to iterate
function myfun that, in addition to the primary objective to be minimized
('minimize.me'), could return other values such as alternative metrics of the
minimization, informative intermediate values from the calculations, etc.
myfun <- function()
{
...
return(list(minimize.me = minimize.me, R2 = R2, pval = pval, etc.))
}
During the iteration, optim could utilize just the first value from the myfun
return list; all the other values calculated and returned by myfun could be
ignored by optim.
After convergence, the other return values of myfun could be finally extracted and
appended into the optim return value (which is a list) as additional entry e.g.:
$aux <- list(R2, pval, etc.), (without 'minimize.me' as it is already returned
as $value).
The usual ways for accessing optim return values, e.g., $par, $value, etc. are
not affected. Computational cost may not be prohibitive either. Is this
feasible to consider?
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Re: [Rd] random network disconnects
В Mon, 31 Jul 2023 16:43:17 +0100 Patrick Burns пишет: > At work we are getting lots of issues with 'permission denied' or > 'network not found' and so forth when reading and writing between our > machines and a file server. This happens randomly so the following > function solves the problem for 'cat' commands These sound like error codes returned from the operating system, which R has no choice but forward to the user. (Well, in this case the error turns out to be transient, but files are unfortunately fraught with peril with no easy solutions [*].) Even using system call tracing or setting a symbolic debugger breakpoint on an error return from cat() will only tell you the OS error code and the file on which the operation failed, both of which you already know. Getting to the root of the problem will likely involve drilling down into the details of the exact networked filesystem used, which R is supposed to know nothing about. Maybe you could ask on ServerFault or on #linux / #windows / # on Libera.Char? -- Best regards, Ivan [*] https://danluu.com/deconstruct-files/ __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
[Rd] HTML documentation check works best with Tidy >= 5.0.0
Hello R-devel, Old versions of HTML Tidy report false positive NOTEs for the HTML verison of the manual where Tidy encounters HTML5 features it is not ready for. Conveniently, both HTML5 support and release version numbers officially appeared in HTML Tidy version 5.0.0 [*]. For example, the last version of the "old Tidy" I could find fails on an R help page: cvs -z3 -d:pserver:anonym...@tidy.cvs.sourceforge.net:/cvsroot/tidy \ co -P tidy cd tidy make -C build/gmake bin/tidy -v # HTML Tidy for Linux released on 25 March 2009 R-devel CMD Rdconv .../R-devel/src/library/stats/man/lm.Rd -t html | \ bin/tidy >/dev/null # line 4 column 1 - Warning: inserting "type" attribute # line 12 column 1 - Warning:
[Rd] hist(..., log="y")
Sorry if this topic has been discussed earlier. Currently, hist(..., log="y") fails with > hist(rexp(1000, 1), log="y") Warning messages: 1: In plot.window(xlim, ylim, "", ...) : nonfinite axis=2 limits [GScale(-inf,2.59218,..); log=TRUE] -- corrected now 2: In title(main = main, sub = sub, xlab = xlab, ylab = ylab, ...) : "log" is not a graphical parameter 3: In axis(1, ...) : "log" is not a graphical parameter 4: In axis(2, at = yt, ...) : "log" is not a graphical parameter The same applies for log="x" > hist(rexp(1000, 1), log="x") Warning messages: 1: In plot.window(xlim, ylim, "", ...) : nonfinite axis=1 limits [GScale(-inf,0.954243,..); log=TRUE] -- corrected now 2: In title(main = main, sub = sub, xlab = xlab, ylab = ylab, ...) : "log" is not a graphical parameter 3: In axis(1, ...) : "log" is not a graphical parameter 4: In axis(2, at = yt, ...) : "log" is not a graphical parameter This applies for the current svn version of R, and also a few recent published versions. This is unfortunate for two reasons: * the error message is not quite correct--"log" is a graphical parameter, but "hist" does not support it. * for various kinds of data it is worthwhile to make histograms in log scale. "hist" is a very nice and convenient function and support for log scale would be handy here. I also played a little with the code, and it seems to be very easy to implement. I am happy to make a patch if the team thinks it is worth pursuing. Cheers, Ott [[alternative HTML version deleted]] __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
