Displaying 20 results from an estimated 30000 matches similar to: "standard errors in predict.nls ()"
2007 May 31
1
predict.nls - gives error but only on some nls objects
Dear list,
I have encountered a problem with predict.nls (Windows XP, R.2.5.0), but I am not sure if it is a bug...
On the nls man page, an example is:
DNase1 <- subset(DNase, Run == 1)
fm2DNase1 <- nls(density ~ 1/(1 + exp((xmid - log(conc))/scal)),
data = DNase1,
start = list(xmid = 0, scal = 1))
alg = "plinear", trace =
2011 Apr 20
1
How can I 'predict' from an nls model with a fit specified for separate groups?
Following an example on p 111 in 'Nonlinear Regression with R' by Ritz &
Streibig, I have been fitting nls models using square brackets with the
grouping variable inside. In their book is this example, in which
'state' is a factor indicating whether a treatment has been used or not:
> Puromycin.m1 <- nls(rate ~ Vm[state] *
+ conc/(K[state] + conc), data = Puromycin,
2006 Jan 18
1
se.fit in predict.nls
The option se.fit in predict.nls is currently ignored.
Is there any other function available to calculate the
error in the predictions?
Thanks,
Manuel
______________________________________________
LLama Gratis a cualquier PC del Mundo.
Llamadas a fijos y m??viles desde 1 c??ntimo por minuto.
2012 May 16
2
confidence intervals for nls or nls2 model
Hi all
I have fitted a model usinf nls function to these data:
> x
[1] 1 0 0 4 3 5 12 10 12 100 100 100
> y
[1] 1.281055090 1.563609934 0.001570796 2.291579783 0.841891853
[6] 6.553951324 14.243274230 14.519899320 15.066473610 21.728809880
[11] 18.553054450 23.722637370
The model fitted is:
modellogis<-nls(y~SSlogis(x,a,b,c))
It runs OK. Then I calculate
2003 Nov 24
2
How to get the parameters of nls(...) for later use
Hi all,
I need to use the parameter estimates of nls() for further analysis. I
know how to do in S+, e.g. nls(...)$parameters. In R, the
attributes(nls(...)) does not have parameters, how would one get the
parameter values out of nls()?
Thanks in advance.
Nancy
2008 Nov 03
2
standard errors for predict.nls?
Dear all,
Is there a way to retrieve standard errors from nls models? The help page tells me that arguments
such as se.fit are ignored...
Many thanks and best wishes
Christoph
--
Dr. rer.nat. Christoph Scherber
University of Goettingen
DNPW, Agroecology
Waldweg 26
D-37073 Goettingen
Germany
phone +49 (0)551 39 8807
fax +49 (0)551 39 8806
Homepage http://www.gwdg.de/~cscherb1
2012 Jun 05
1
- help with the predict function
Hi all,
I would like to predict some values for an nls regression function
(functional response model Rogers type II). This is an asymptotic function
of which I would like to predict the asymptotic value
I estimated the paramters with nls, but can't seem to get predictions for
values of m choice......
This is my script:
RogersII_N <-
2011 Jul 18
1
nls() and lines()
All -
I'm having an issue with trying to plot a model derived from nls()
onto a simple plot.? I have included a sample data set and the code
that I've been using.
?? year month day?????? date location mileage? cost gallon????? cpg
? mpg????????? x
2009???? 1?? 4?? 1/4/2009????? BZN? 124585 19.39? 14.37 1.349339
10.71677 2009-01-04
2009???? 1? 15? 1/15/2009????? BZN? 124888? 23.2? 16.12
2020 Oct 17
2
??? is to nls() as abline() is to lm() ?
I'm drawing a fitted normal distribution over a histogram. The use case is trivial (fitting normal distributions on densities) but I want to extend it to other fitting scenarios. What has stumped me so far is how to take the list that is returned by nls() and use it for curve(). I realize that I can easily do all of this with a few intermediate steps for any specific case. But I had expected
2010 Aug 13
2
Unable to retrieve residual sum of squares from nls output
Colleagues,
I am using "nls" successfully (2.11.1, OS X) but I am having difficulties retrieving part of the output - residual sum of squares. I have assigned the output to FIT:
> > FIT
> Nonlinear regression model
> model: NEWY ~ PMESOR + PAMPLITUDE * cos(2 * pi * (NEWX - POFFSET)/PERIOD)
> data: parent.frame()
> PMESOR PAMPLITUDE POFFSET
>
2020 Oct 17
0
??? is to nls() as abline() is to lm() ?
I haven't followed your example closely, but can't you use the predict()
method for this? To draw a curve, the function that will be used in
curve() sets up a newdata dataframe and passes it to predict(fit,
newdata= ...) to get predictions at those locations.
Duncan Murdoch
On 17/10/2020 5:27 a.m., Boris Steipe wrote:
> I'm drawing a fitted normal distribution over a
2009 Sep 08
1
Confident interval for nls predictions
Hello all,
I'm trying to establish some confidence intervals on predictions I am making using
>predict(nls(...))
and predict.nls (unfortunately) does not utilize the se.fit option. A little more background is that I am trying to match the output with older SAS routines to maintain consistency. Because predict.nls does not provide se's for individual predictions, I have been using a
2004 Oct 07
1
confidence interval for nls
Do I have the right impression that it's currently not possible to
produce confidence intervals for the nls predictions using R?
I had a course were we used SAS PROC nlin and there you could get
intervals for the parameters and the prediction but I do not have access
to SAS.
Would it be difficult to implement, I tried to dig into the help pages
of nls, vcov and nlsModel but I could not
2011 May 07
5
plotting confidence bands from predict.nls
I am trying to find a confidence band for a fitted non-linear curve. I
see that the predict.nls function has an interval argument, but a
previous post indicates that this argument has not been implemented. Is
this still true? I have tried various ways to extract the interval
information from the model object without success. My code is:
Model.predict <- predict(My.nls.model,
2013 Apr 05
1
white heteroskedasticity standard errors NLS
Hello
Is there any function to calculate White's standard errors in R in an NLS
regression.
The sandwich and car package do it but they need an lm object to calculate
the error's.
Does anyone have idea how to do it for an NLS object ?
Regards
The woods are lovely, dark and deep
But I have promises to keep
And miles before I go to sleep
And miles before I go to sleep
-----
[[alternative
2006 Mar 09
0
variable '%s' was fitted with class... in predict.nls()
I've tried to predict the values from a new data.frame using the
nls.predict function and keep getting the error message:
Error in if (sum(wrong) == 1) stop(gettextf("variable '%s' was fitted with
class \"%s\" but class \"%s\" was supplied", :
missing value where TRUE/FALSE needed
I first thought that it was becuase there may have been something
2010 Mar 25
1
nls, predict() problem
hello,
can anyone help with this:
###########################################################
###data: measurments (response = trans) run several times at the same
predictor value level (press)
por<-data.frame(list(structure(list(run = structure(c(1L, 1L, 1L, 1L, 2L,
2L,
2L, 2L, 3L, 3L, 3L, 3L), .Label = c("1", "3", "4"), class = "factor"),
press
2002 Jul 09
1
lines(predict(nls()) with NA's
Dear List,
my exploration of R goes on... And I REALLY enjoy it ! (thanks to all guRus).
Yesterday a colleague ask me for fitting some data presented as a data.frame,
something like :
>a
x X158.7 X150.0 ...
1 -0.25 506 183.1
2 -0.75 633 210.7
3 -1.25 674 220.3
4 -1.50 NA 244.6
5 -1.75 742 261.2
6 -2.25 787 269.1
7 -2.50 NA 283.5
8
2009 Apr 05
4
predicting values into the future
Hi:
I have usually used the GROWTH() excel function to do this but now want to see if I can do this with R.
I want to predict values into the future, possibly with the predict.arima Function.
I have the following weekly fish weight averages:
weight <- c("2.1","2.4","2.8","3.6","4.1","5.2","6.3")
week <-
2004 Feb 04
1
Fitting nonlinear (quantile) models to linear data.
Hello.
I am trying to fit an asymptotic relationship (nonlinear) to some
ecological data, and am having problems. I am interested in the upper
bound on the data (i.e. if there is an upper limit to 'y' across a range
of 'x'). As such, I am using the nonlinear quantile regression package
(nlrq) to fit a michaelis mention type model.
The errors I get (which are dependant on