Displaying 20 results from an estimated 300 matches similar to: "gnm and gnlr3"
2012 Apr 19
1
non-numeric argument in mle2
Hi all,
I have some problems with the mle2 function
> RogersIIbinom <- function(N0,attackR3_B,Th3_B)
{N0-lambertW(attackR3_B*Th3_B*N0*exp(-attackR3_B*(24-Th3_B*N0)))/(attackR3_B*Th3_B)}
> RogersII_B <-
mle2(FR~dbinom(size=N0,prob=RogersIIbinom(N0,attackR3_B,Th3_B)/N0),start=list(attackR3_B=1.5,Th3_B=0.04),method="Nelder-Mead",data=dat)
Error in dbinom(x, size, prob, log)
2012 Jun 07
3
- detecting outliers
Hello all,
I am estimating parameters for regression functions on experimental data.
Functional response of Rogers type II.
I would like to know which points of my dataset are outliers. What is the
best method to do this with R?
I found a method via R help, but would like to know if there are better
methods for my purpose.
Here is the script I us now:
library("mvoutlier")
dat
2012 Apr 18
1
error estimating parameters with mle2
Hi all,
When I try to estimate the functional response of the Rogers type I
equation (for the mle2 you need the package bbmle):
> RogersIbinom <- function(N0,attackR2_B,u_B) {attackR2_B+u_B*N0}
> RogersI_B <-
mle2(FR~dbinom(size=N0,prob=RogersIbinom(N0,attackR2_B,u_B)/N0),start=list(attackR2_B=4.5,u_B=0.16),method="Nelder-Mead",data=data5)
I get following error message
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 <-
2012 Apr 03
3
regression for poisson distributed data
Hello all,
I would like to get parameter estimates for different models. For one of
them I give the code in example. I am estimating the parameters (i,j and
k) with the nls function, which sees the error distribution as normal, I
would however like to do the same as nls with the assumption that the
errors are poisson distributed.
Is there a way to do this with R? Are there packages designed
2012 Apr 16
0
automatically scan multiple starting values
Hi all,
I am doing nls regression of the Rogers type III equation. However I can't
find good starting values and keep getting the error messages: "Missing
value or an infinity produced when evaluating the model" OR "singular
gradient matrix at initial parameter estimates"
Is there a way to automatically check different starting values and give a
list of values for each
2005 Apr 15
1
gnlr3 location parameter
Hi list,
my previous question was obviously too basic to deserve an answer -
apologies for that. I'm learning, things can only get better :-)
My current problem is with fitting a generalized gamma distribution with
an additional "shift" parameter, that represents a shift of the
distribution along the X axis.
The gnlr3 function (in Jim Lindsey's GNLM package) fits this
2005 Apr 14
0
gnlr/3 question
Hi list,
I'd like to fit generalized gamma and weibull distributions to a number
of data sets. I've been searching around and found references to R and
Jim Lindsey's GNLM package, which has the gnlr and gnlr3 procedures that
can do this.
Now, I'm completely new to R, and I'm working my way through the
introduction... Nevertheless, I'd like to ask if someone could post
2009 Apr 30
0
Categorical variable in a custom nonlin function with gnm
Hi all
I want to construct a generalised nonlinear model (binomial family) using gnm, of the form:
Response = a + b variable1 + c variable2 + d variable3 - d b variable4 - d c variable5,
with the parameters b, c, and d appearing more than once. Hence, I think I need to use a custom nonlin function with gnm.
One of my predictor variables is categorical, so I have created a dummy variable for
2007 Jan 16
1
nonlinear regression: nls, gnls, gnm, other?
Hi all,
I'm trying to fit a nonlinear (logistic-like) regression, and I'd like
to get some recommendations for which package to use.
The expression I want to fit is something like:
y ~ A * exp(X * Beta1) / (1 + exp(-(x + X * Beta2 - xmid)/scal))
Basically, it's a logistic function, but I want to be able to modify
the saturation amplitude by a few parameters (Beta1) and shift the
2012 Sep 11
1
boot() with glm/gnm on a contingency table
Hi everyone!
In a package I'm developing, I have created a custom function to get
jackknife standard errors for the parameters of a gnm model (which is
essentially the same as a glm model for this issue). I'd like to add
support for bootstrap using package boot, but I couldn't find how to
proceed.
The problem is, my data is a table object. Thus, I don't have one
individual per
2010 Feb 17
0
Help with sigmoidal quasi-poisson regression using glm and gnm functions
Hi everyone,
I'm trying to perform the following regressions in order to compare linear
vs. sigmoidal fit of the relationship between my dependent variable (y) and
one explaining parameter (x2), both including the confounding effects of a
third variable (x1):
quasi-pois-lin <- glm(y ~ x1 + x2, family = quasipoisson(link="identity"),
data=fit)
quasi-pois-sig <- gnm(y ~ x1 +
2008 Apr 10
1
Fit a nonlinear regression model with power exponentially distributed errors
How to fit a nonlinear regression model with power exponentially distributed
errors? I know gnlm has a function gnlr3 that could work, but I would be
grateful if example R code is provided.
Daniel
[[alternative HTML version deleted]]
2000 Feb 03
1
Re: your mail
> On Wed, 2 Feb 2000, Adriane Leal wrote:
>
> > I'd like to perform a box-cox transformation to a data set and also plot
> > lambda versus L(lambda) using R. Does anybody knows how can I do such a
> > thing?
gnlr3 in my gnlm library does both linear and nonlinear models with
Box-Cox transformation. However, it is somewhat nonstandard as it
renormalizes to obtain a
2015 Apr 29
2
Formula evaluation, environments and attached packages
Hi!
Some time ago, I replaced calls to library() with calls to
requireNamespace() in my package logmult, in order to follow the new
CRAN policies. But I just noticed it broke jackknife/bootstrap using
several workers via package parallel.
The reason is that I'm running model replicates on the workers, and the
formula includes non-standard terms like Mult() which are provided by
gnm. If gnm
2006 Jun 09
0
R CMD check and directory/package name
The NEWS for R 2.3.0 states that
"R CMD check works for packages whose package name is different from the directory name in which it is located."
However that hasn't been my experience. I ran R CMD check on package sources located in a directory with the same name as the package and it worked as expected. Then I renamed the directory and tried again. The first attempt got stuck
2015 Apr 29
0
Formula evaluation, environments and attached packages
Hi Milan,
I expect I may be able to do something about the way the terms are
evaluated, to ensure the evaluation is done in the gnm namespace (while
still ensuring the variables can be found!).
In the meantime, I think the following will work:
Mult <- gnm::Mult
f <- Freq ~ Eye + Hair + Mult(Eye, Hair)
gnm::gnm(f, family=poisson, data=dat)
Hope that helps,
Heather
On Wed, Apr 29, 2015,
2013 Aug 22
1
Confusion about Depends:, Imports:, Enhances:, import(), inportFrom()
In checking my vcdExtra package, the following NOTE newly appeared
(R-Forge, using R version 3.0.1 Patched (2013-08-20 r63635))
Package in Depends field not imported from: ?gnm?
These packages needs to imported from for the case when
this namespace is loaded but not attached.
In the DESCRIPTION file, I have
Depends: R (>= 2.10), vcd, gnm (>= 1.0.3)
In NAMESPACE:
# we are a vcd
2010 Jul 06
1
nls + quasi-poisson distribution
Hello R-helpers,
I would like to fit a non-linear function to data (Discrete X axis,
over-dispersed Poisson values on the Y axis).
I found the functions gnlr in the gnlm package from Jim Lindsey: this can
handle nonlinear regression equations for the parameters of Poisson and
negative binomial distributions, among others. I also found the function
nls2 in the software package
2006 Dec 14
3
Model formula question
Hi all,
I'm not familiar with R programming and I'm trying to reproduce a
result from a paper.
Basically, I have a dataset which I would like to model in terms of
successive increments, i.e. (y denote empirical values of y)
y_1 = y1,
y_2 = y1 + delta1,
y_3 = y1 + delta1 + delta2.
...
y_m = y1 + sum_2^m delta j
where delta_j donote successive increments in the y-values, i.e.
delta