Displaying 20 results from an estimated 400 matches similar to: "optim question"
2011 Dec 12
1
Detecting typo in function argument
With some chagrin after spending a couple of hours trying to debug a script, I realized I
had typed in something like
ans<-optimx(start, myfn, mygr, lower<-lo, upper=up)
that is, the "<-" rather than "=". The outcome on my machine was a non-obvious error
several layers deep in the call stack. For info, optim() seems to stop much more quickly.
The error is
2009 May 13
2
[LLVMdev] Loop-carried Dependence
Hi,
Does anyone know if there is any existing code I can use to do a
loop-carried dependence analysis for LLVM IR programs? I searched the
mailing-list archive and it seems like someone planned to implement a
loop dependence analysis pass in March. I'm just wondering if this
project is ongoing/finished or if there is other projects that may
have the code I'm interested in.
Thanks!
2009 May 15
0
[LLVMdev] Loop-carried Dependence
Hi Wenhao Jia,
On Wed May 13 16:30:36 +0200 2009, Wenhao Jia wrote:
> Does anyone know if there is any existing code I can use to do a
> loop-carried dependence analysis for LLVM IR programs? I searched the
> mailing-list archive and it seems like someone planned to implement a
> loop dependence analysis pass in March. I'm just wondering if this
> project is ongoing/finished or
2009 Mar 03
1
[LLVMdev] Control Data Flow Graph (CDFG)
Hi,
Does anyone know any tool that can help generate a control/data flow graph
(CDFG) for LLVM IR programs?
The opt -view-cfg and related commands can visualize a program as a control
flow graph. But how can I embody data flow information into that graph?
Your help will be greatly appreciated!
Thanks,
Wenhao Jia
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2011 Aug 29
3
gradient function in OPTIMX
Dear R users
When I use OPTIM with BFGS, I've got a significant result without an error
message. However, when I use OPTIMX with BFGS( or spg), I've got the
following an error message.
----------------------------------------------------------------------------------------------------
> optimx(par=theta0, fn=obj.fy, gr=gr.fy, method="BFGS",
>
2017 Dec 31
1
Order of methods for optimx
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
2011 Aug 13
3
optimization problems
Dear R users
I am trying to use OPTIMX(OPTIM) for nonlinear optimization.
There is no error in my code but the results are so weird (see below).
When I ran via OPTIM, the results are that
Initial values are that theta0 = 0.6 1.6 0.6 1.6 0.7. (In fact true vales
are 0.5,1.0,0.8,1.2, 0.6.)
--------------------------------------------------------------------------------------------
>
2009 Mar 04
1
[LLVMdev] Control Data Flow Graph (CDFG)
Hi John,
My project is somewhat inbetween, but closer to the latter.
If you are doing something related to synthesis, have you checked
xPilot from UCLA? Search "llvm" in this paper
<http://www.icims.csl.uiuc.edu/~dchen/xpilot-TechCon2005.pdf>
Anyway, thanks for the information! :-)
Wenhao
On Tue, Mar 3, 2009 at 6:30 AM, <llvmdev-request at cs.uiuc.edu> wrote:
>
>
2011 Feb 06
1
function optimization
Dear all,
this is my first time, and just begin to use R. But I've a question about
optimization using optimx library. It could sound stupid by I'm a bit
affraid with the problem, because anything I try, anything Error.
The procedure was:
optimx(par="10,71,1",fn=(Prey*Provisioning)/Risk, control=list("maximize))
well the problem lies in the initial value parameters, again
2011 Nov 29
2
Parameters setting in functions optimization
Good afternoon everybody,
I'm quite new in functions optimization on R and, whereas I've read
lot's of function descriptions, I'm not sure of the correct settings for
function like "optimx" and "nlminb".
I'd like to minimize my parameters and the loglikelihood result of the
function.
My parameters are a mean distance of dispersion and a proportion of
2011 Sep 10
1
control list gotcha
This is mainly a reminder to others developing R packages to be careful not to supply
control list items that are not used by the called package. Optimx is a wrapper package
that aims to provide a common syntax to a number of existing optimization packages.
Recently in extending optimx package I inadvertently introduced a new control for optimx
which is NOT in any of the wrapped optimization
2019 Jan 31
1
nlminb with constraints failing on some platforms
Prof Nash, Prof Galanos
Is it possible to use a generic code stub in front of packages that use
optimx to improve optimx use or curtail it according to the requirements?
Best Regards
Amit
+91 7899381263
________________________________________________________________________
Please request Skype as available
5th Year FPM (Ph.D.) in Finance and Accounting Area
Indian Institute
2016 Oct 09
1
optim(?, method=?L-BFGS-B?) stops with an error
I'll not copy all the previous material on this thread to avoid overload.
The summary is that all the methods Spencer has tried have some issues.
The bad news: This is not uncommon with optimization methods, in part because the problems are "hard",
in part because getting them implemented and linked to an interfacing approach like R is very tedious
and prone to omissions and
2016 Oct 08
4
optim(…, method=‘L-BFGS-B’) stops with an error message while violating the lower bound
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
2016 Oct 08
4
optim(…, method=‘L-BFGS-B’) stops with an error message while violating the lower bound
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
2011 Nov 02
1
overly long lines in pdf output of manual from package
In re-factoring my optimx package, I'm finding that the pdf output has some lines that are
outside the margins (and there are warnings in R CMD check optimx). Clearly I can fix this
by editing the tex file that is generated, but the build infrastructure would still get
things wrong in automatic processing. So that gives rise to 3 questions:
1) How do I adjust the DESCRIPTION file to avoid too
2010 Jun 22
1
Subject: Re ZINB by Newton Raphson??
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
2009 Oct 07
1
[LLVMdev] Use LoopInfo in a non-pass class such as ProfileInfoLoader?
Hi everyone,
I'm adding loop profiling to LLVM built-in profiler. I'm just
wondering in a class that's not a pass, such as ProfileInfoLoader, how
can I get information produced by passes such as LoopInfo and
DominatorTree?
In other words, ProfileInfoLoader is not a pass, so it can't call
AnalysisUsage::addRequired and AnalysisUsage::getAnalysisUsage
directly. Then how can it know
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
2011 Aug 31
1
Gradients in optimx
Hi Reuben,
I am puzzled to note that the gradient check in "optimx" does not work for you. Can you send me a reproducible example so that I can figure this out?
John - I think the best solution for now is to issue a "warning" rather than an error message, when the numerical gradient is not sufficiently close to the user-specified gradient.
Best,
Ravi.