nls() is using
1) only a Gauss-Newton code which is prone to some glitches
2) approximate derivatives
Package nlmrt uses symbolic derivatives for expressions (you have to
provide Jacobian code for R functions) and an aggressive Marquardt
method to try to reduce the sum of squares. It does return m
On my Windows Vista system it returns an answer:
> values <- list(x=10:30, y=c(23.85, 28.805, 28.195, 26.23, 25.005, 20.475,
+ 17.33, 14.97, 11.765, 8.857, 5.3725, 5.16, 4.2105, 2.929, 2.174, 1.25, 1.0255,
+ 0.612, 0.556, 0.4025, 0.173))
> y.max <- max(values$y)
> model <- nls(y ~ SSlogis(x, asym,
> "PD" == Peter Dalgaard <[EMAIL PROTECTED]>
> on Fri, 04 Jan 2008 18:23:33 +0100 writes:
PD> [EMAIL PROTECTED] wrote:
>> Full_Name: Hendrik Weisser
>> Version: 2.6.1
>> OS: Linux
>> Submission from: (NULL) (139.19.102.218)
>>
>>
>> The following compu
[EMAIL PROTECTED] wrote:
> Full_Name: Hendrik Weisser
> Version: 2.6.1
> OS: Linux
> Submission from: (NULL) (139.19.102.218)
>
>
> The following computation never finishes and locks R up:
>
>
>> values <- list(x=10:30, y=c(23.85, 28.805, 28.195, 26.23, 25.005, 20.475,
>>
> 17.33, 14.97, 11
Full_Name: Hendrik Weisser
Version: 2.6.1
OS: Linux
Submission from: (NULL) (139.19.102.218)
The following computation never finishes and locks R up:
> values <- list(x=10:30, y=c(23.85, 28.805, 28.195, 26.23, 25.005, 20.475,
17.33, 14.97, 11.765, 8.857, 5.3725, 5.16, 4.2105, 2.929, 2.174, 1.25,
This is fixed in the current R-devel.
On Wed, 22 Aug 2007, [EMAIL PROTECTED] wrote:
> Full_Name: Yan Wong
> Version: 2.5.1
> OS: Mac OS X 10.4
> Submission from: (NULL) (129.11.77.198)
>
>
> If nls is called with a large number of variables & parameters (>200), then it
> fails because of the defa
Full_Name: Yan Wong
Version: 2.5.1
OS: Mac OS X 10.4
Submission from: (NULL) (129.11.77.198)
If nls is called with a large number of variables & parameters (>200), then it
fails because of the default setting of max.names = 200 in the all.vars
function. I guess that nls should either give a meani
Hi, All:
The following identifies apparent inconsistencies and proposed
fixes between the documentation and the behavior of 'nls'.
Specifically, the help file says 'data' 'Can also be a list'.
However, I got an error when I tried it with a list that could not be
coerced to a data.
I think we should fix the code to do as the documentation says: all it
needs is an unlist().
Thank you for the examples, which helped test this.
On Mon, 16 Apr 2007, Katharine Mullen wrote:
> The documentation for nls says the following about the starting values:
>
> start: a named list or name
The documentation for nls says the following about the starting values:
start: a named list or named numeric vector of starting estimates.
Since R 2.4.0, when 'start' is missing, a very cheap guess
for 'start' is tried (if 'algorithm != "plinear"').
It may be a good idea to d
I am sorry, it was my program's bug.
Yes, subset works!
Yes, nls works correctly!
I didn't pay enough attention to NAs.
NA threw off start value estimation in my program.
So, I got different results when I filtered NAs beforehand
and filtered by subset.
I also confused because subset does not appe
[EMAIL PROTECTED] writes:
> Full_Name: Tadashi Kadowaki
> Version: 2.4.0
> OS: Redhat Linux 9
> Submission from: (NULL) (58.12.166.67)
>
>
> Doesn't nls function support subset? It seems not to work.
> And, there are no information in the online help.
> Has it sunk into oblivion?
Whatever gave
This is not the place to ask a question: do read the FAQ.
?nls shows that nls does have a 'subset' argument, and it does work.
Compare
> ?nls
> x <- 1:10
> y <- 2*x + 3# perfect fit
> yeps <- y + rnorm(length(y), sd = 0.01) # added noise
> nls(yeps ~ a + b*x, start = l
Full_Name: Tadashi Kadowaki
Version: 2.4.0
OS: Redhat Linux 9
Submission from: (NULL) (58.12.166.67)
Doesn't nls function support subset? It seems not to work.
And, there are no information in the online help.
Has it sunk into oblivion?
__
R-devel@r-p
Dear Professors. Bolker & Ripley:
Thank you both very much for all your creativity and hard work
both in your generall contributions to human knowledge and specifically
for helping make R the great thing it is today. I had not seen a reply
to that email in several days, so I made time t
Spencer Graves pdf.com> writes:
>
> Hi, Ben, et al.:
>
> The issue Ben identified with confint(nls(... )) generates a hard
> failure for me.
"We" (being Brian Ripley and I) know about this already.
I'm sorry I failed to specify enough info in my bug report,
but I was using R-dev
Hi, Ben, et al.:
The issue Ben identified with confint(nls(... )) generates a hard
failure for me. Specifically the command "confint(m1)" in his script
below under Rgui 2.2.1 first says, "Waiting for profiling to be done..."
then forces a screen to pop up with heading "R for Windows
[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
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 below ...
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
major2
min
hi everybody,
which each release I hope that the section
"weights: an optional numeric vector of (fixed) weights. When present,
the objective function is weighted least squares. _not yet
implemented_"
in the help page of 'nls' is missing the last sentence.
are their any p
[EMAIL PROTECTED] writes:
> Full_Name: Carsten Urbach
> Version: 2.1.1 (2005-06-20)
> OS: Linux
> Submission from: (NULL) (141.34.5.241)
>
>
> I observed one case where nls failed to return the correlation matrix, while
> the
> parameter estimates were computed correctly. In the follwing I inc
Full_Name: Carsten Urbach
Version: 2.1.1 (2005-06-20)
OS: Linux
Submission from: (NULL) (141.34.5.241)
I observed one case where nls failed to return the correlation matrix, while the
parameter estimates were computed correctly. In the follwing I include all the
commands leading to this problem.
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