Displaying 20 results from an estimated 2000 matches similar to: "nls profile with port/constraints"
2006 Jan 19
1
nls profiling with algorithm="port" may violate bounds (PR#8508)
[posted to R-devel, no discussion:
resubmitting it as a bug, just so it gets
logged appropriately]
Sorry to report further difficulties with
nls and profiling and constraints ... the problem
this time (which I didn't check for in my last
round of testing) is that the nls profiler doesn't
seem to respect constraints that have been
set when using the port algorithm.
See test code
2005 Jan 10
1
mle() and with()
I'm trying to figure out the best way of fitting the same negative
log-likelihood function to more than one set of data, using mle() from the
stats4 package.
Here's what I would have thought would work:
--------------
library(stats4)
## simulate values
r = rnorm(1000,mean=2)
## very basic neg. log likelihood function
mll <- function(mu,logsigma) {
2006 Jan 23
1
too-large notches in boxplot (PR #7690)
PR #7690 points out that if the confidence intervals (+/-1.58
IQR/sqrt(n)) in a boxplot with notch=TRUE are larger than the
hinges -- which is most likely to happen for small n and asymmetric
distributions -- the resulting plot is ugly, e.g.:
set.seed(1001)
npts <- 5
X <- rnorm(2*npts,rep(3:4,each=npts),sd=1)
f <- factor(rep(1:2,each=npts))
boxplot(X~f)
boxplot(X~f,notch=TRUE)
I can
2006 Jan 08
1
confint/nls
I have found some "issues" (bugs?) with nls confidence intervals ...
some with the relatively new "port" algorithm, others more general
(but possibly in the "well, don't do that" category). I have
corresponded some with Prof. Ripley about them, but I thought I
would just report how far I've gotten in case anyone else has
thoughts. (I'm finding the code
2005 Dec 15
0
nls: constraints (lower/upper) (PR#8401)
I found what seems to be a glaring bug in nls when using
constraints, but it is so glaring that I'm a bit nervous
about having been stupid. I have (1) tried to make sure
I'm up to date:
platform i486-pc-linux-gnu
arch i486
os linux-gnu
system i486, linux-gnu
status
major 2
minor 2.0
year 2005
month 10
day 06
svn rev 35749
(2) skimmed through the SVN
2010 Jan 27
1
term.formula error when updating an nls object
Hi,
I'm getting an error that I don't understand when updating an nls
object. Here is a toy example.
dd <- structure(list(Contrast = c(0.00376, 0.03759, 0.12782, 0.25564,
0.50376, 1), Response = c(0.29915, 6.13248, 29.01709, 30.0641,
29.46581, 27.67094)), .Names = c("Contrast", "Response"), class =
"data.frame", row.names = c(NA,
-6L))
m1 <-
2005 Jul 21
1
About object of class mle returned by user defined functions
Hi,
There is something I don't get with object of class "mle" returned by a
function I wrote. More precisely it's about the behaviour of method
"confint" and "profile" applied to these object.
I've written a short function (see below) whose arguments are:
1) A univariate sample (arising from a gamma, log-normal or whatever).
2) A character string
2015 Mar 27
0
robust updating methods
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[Sorry to those who don't like it for top-posting]
Thierry, I'm curious whether this addresses your problem (although
we don't have a hard timetable for the next release [it has to avoid
conflicts with the 3.2.0 release in 2.5 weeks at the very least], so
this might be problematic if your package needs to depend on it).
I'm
2004 Jun 10
1
overhaul of mle
So, I've embarked on my threatened modifications to the mle subset
of the stats4 package. Most of what I've done so far has *not* been
adding the slick formula interface, but rather making it work properly
and reasonably robustly with real mle problems -- especially ones
involving reasonably complex fixed and default parameter sets.
Some of what I've done breaks backward
2023 Dec 19
1
[External] Re: zapsmall(x) for scalar x
>>>>> Steve Martin
>>>>> on Mon, 18 Dec 2023 07:56:46 -0500 writes:
> Does mFUN() really need to be a function of x and the NA values of x? I
> can't think of a case where it would be used on anything but the non-NA
> values of x.
> I think it would be easier to specify a different mFUN() (and document this
> new argument)
2010 Oct 11
1
MATLAB vrs. R
I need to find the area under a trapezoid for a research-related project. I was able to find the area under the trapezoid in MATLAB using the code:
function [int] = myquadrature(f,a,b)
% user-defined quadrature function
% integrate data f from x=a to x=b assuming f is equally spaced over the interval
% use type
% determine number of data points
npts = prod(size(f));
nint = npts -1; %number of
2004 May 07
1
mle
I'm very excited by the new mle package now incorporated in stats4. If
possible, I'd like to help develop it. In the past I wrote a similar
package (mleprof, available from http://www.zoo.ufl.edu/bolker/R/src), and
would like to see if there's anything that my package does that I could
contribute (in particular, I'd like to make sure that the code is as
robust as possible in
2007 Feb 08
0
strategies for incorporating a data= argument
As I've mentioned here, before, I'm working on an extended
version of mle(), a function from the stats4 package that's
a wrapper for optim().
I'd like (against the advice of Peter Dalgaard -- sorry) to
incorporate a "data" argument, similar to the arguments in
lm, nls, nlme, etc., that would allow the log-likelihood function
to be evaluated with different sets of data.
2011 May 04
0
Fwd: simple question
Sorry I had typo in previous email,
this typo corrected version:
Dear R experts
I have simple question, please execuse me:
#example data, the real data consists of 20000 pairs of variables
K1 <- c(1,2,1, 1, 1,1); K2 <- c(1, 1,2,2, 1,2); K3 <- c(3, 1, 3, 3, 1, 3)
M1a <- rep( K1, 100); M1b <- rep(K2, 100)
M2a <- rep(K1, 100); M2b <- rep(K1, 100)
M3a <- rep(K1, 100); M3b
2015 Mar 24
2
robust updating methods
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On 15-03-23 12:55 PM, Thierry Onkelinx wrote:
> Dear Ben,
>
> Last week I was struggling with incorporating lme4 into a package.
> I traced the problem and made a reproducible example (
> https://github.com/ThierryO/testlme4). It looks very simular to
> the problem you describe.
>
> The 'tests' directory contains
2010 Feb 12
1
using mle2 for multinomial model optimization
Hi there
I'm trying to find the mle fo a multinomial model ->*L(N,h,S?x)*. There
is only *N* I want to estimate, which is used in the number of successes
for the last cell probability. These successes are given by:
p^(N-x1-x2-...xi)
All the other parameters (i.e. h and S) I know from somewhere else.
Here is what I've tried to do so far for a imaginary data set:
2007 Feb 13
1
lme4/lmer: P-Values from mcmc samples or chi2-tests?
Dear R users,
I have now tried out several options of obtaining p-values for
(quasi)poisson lmer models, including Markov-chain Monte Carlo sampling
and single-term deletions with subsequent chi-square tests (although I
am aware that the latter may be problematic).
However, I encountered several problems that can be classified as
(1) the quasipoisson lmer model does not give p-values when
2023 Dec 18
1
[External] Re: zapsmall(x) for scalar x
Does mFUN() really need to be a function of x and the NA values of x? I
can't think of a case where it would be used on anything but the non-NA
values of x.
I think it would be easier to specify a different mFUN() (and document this
new argument) if the function has one argument and is applied to the non-NA
values of x.
zapsmall <- function(x,
digits = getOption("digits"),
2007 Feb 14
0
environment confusion
I'm in a bit beyond my depth with environments and such.
The environment of a particular function, which I've set
so it should have the things it needs, seems to be getting
"lost" at some point during a call sequence.
It's hard to come up with a _simple_ reproducible
example, although if anyone's sufficiently interested I
can post the package somewhere -- with the
2006 Oct 24
0
Variables ordering problem in mle() (PR#9313)
Full_Name: S?bastien Villemot
Version: 2.4.0
OS: Debian testing
Submission from: (NULL) (62.212.121.128)
Hi,
In the mle() function of the stats4 package, there is a bug in the ordering of
the variables given in the 'start' argument.
By just changing the order of the variables listed in the 'start' list (the
initialization values), it is possible to obtain different estimation