Displaying 20 results from an estimated 1100 matches similar to: "ifelse and piecewise function"
2011 Aug 18
3
Error message: object of type 'closure' is not subsettable
Dear R-users
I need to calibrate kappa, rho, eta, theta, v0 in the following code, see
below. However when I run it, I get:
y <- function(kappahat, rhohat, etahat, thetahat, v0hat) {sum(difference(k,
t, S0, X, r, implvol, q, kappahat, rhohat, etahat, thetahat, v0hat)^2)}
> nlminb(start=list(kappa, rho, eta, theta, v0), objective = y, lower =lb,
> upper =ub)
Error in dots[[1L]][[1L]] :
2015 Jul 15
1
Two bugs showing up mostly on SPARC systems
On Tue, Jul 14, 2015 at 07:52:56PM -0400, Duncan Murdoch wrote:
> On 14/07/2015 6:08 PM, Radford Neal wrote:
> > In testing pqR on Solaris SPARC systems, I have found two bugs that
> > are also present in recent R Core versions. You can see the bugs and
> > fixes at the following URLs:
> >
> >
2009 Feb 19
2
bugfix for nls with port algorithm (PR#13540)
Full_Name: Manuel A. Morales
Version: 2.8.1
OS: Linux
Submission from: (NULL) (137.165.199.246)
When fitting a model in nls using the algorithm port with constraints and the
shorthand parameter[factor] in the model, I get the following error message:
"Error in nls_port_fit(m, start, lower, upper, control, trace) :
(list) object cannot be coerced to type 'double'
In addition:
2009 Apr 12
3
p-values from bootstrap - what am I not understanding?
Dear stats experts:
Me and my little brain must be missing something regarding bootstrapping. I
understand how to get a 95%CI and how to hypothesis test using bootstrapping
(e.g., reject or not the null). However, I'd also like to get a p-value from
it, and to me this seems simple, but it seems no-one does what I would like
to do to get a p-value, which suggests I'm not understanding
2015 Jul 14
3
Two bugs showing up mostly on SPARC systems
In testing pqR on Solaris SPARC systems, I have found two bugs that
are also present in recent R Core versions. You can see the bugs and
fixes at the following URLs:
https://github.com/radfordneal/pqR/commit/739a4960a4d8f3a3b20cfc311518369576689f37
https://github.com/radfordneal/pqR/commit/339b7286c7b43dcc6b00e51515772f1d7dce7858
The first bug, in nls, is most likely to occur on a 64-bit
2010 May 24
2
How to set parameters constraints in a function?
Dear R list,
I have a function specifying my log-likelihood, and now I need to set the
constraint that *alpha > kappa*, could anyone help me with setting this in
my function?
the function is defined as follows:
mll <- function(param){
n <- length(x)
psi <- numeric(n)
psi[1] <- 1.0
a0 <- exp(param[1]); a1 <-exp(param[2]); b1 <- exp(param[3]); *alpha *<-
2007 Mar 22
3
Cohen's Kappa
Hi,
im little bit confused about Cohen's Kappa and i should be look into the
Kappa function code. Is the easy formula really wrong?
kappa=agreement-chance/(1-chance)
many thanks
christian
###############################################################################
true-negativ:7445
false-positive:3410
false-negativ:347
true-positiv:772
classification-aggrement:68,6%
2012 Oct 16
4
how to extract from list
Hi all,
I have a list of 20000 data, and the list look like below. I wonder what is
the simplest way to extract 'kappa' value (or 'xi' or 'alpha' for the
matter) from each of the data. How can I simply code it without having to
change the list to a dataframe first? Many thanks!
$X19997
xi alpha kappa
784.7718640 165.4065141 -0.2709599
$X19998
2006 Apr 28
1
Where do I find Cohen´s kappa???
Hello,
I?m looking for a way to measure the goodness of fit of my model with Cohen?s Kappa (scaling between 0 and 1).
The kappa function does not give the results I?m looking for. Heres the code:
z<-glm(x~y,binomial)
kappa(z, exact = T)
Does anyone know more?
many thanks
Christian
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2012 Feb 10
4
function arrows.circular not working
I have started using the circular package but it is not recognizing the function arrows.circular. I attempted to use the example provided in the circular manual. Here is the example code using the circular package:
plot(rvonmises(10, circular(0), kappa=1))
arrows.circular(rvonmises(10, circular(0), kappa=1))
arrows.circular(rvonmises(10, circular(0), kappa=1), y=runif(10), col=2)
2011 Jun 22
1
caret's Kappa for categorical resampling
Hello,
When evaluating different learning methods for a categorization problem with
the (really useful!) caret package, I'm getting confusing results from the
Kappa computation. The data is about 20,000 rows and a few dozen columns,
and the categories are quite asymmetrical, 4.1% in one category and 95.9% in
the other. When I train a ctree model as:
model <- train(dat.dts,
2009 Jul 13
3
Help With Fleiss Kappa
Hi All,
I am using fleiss kappa for inter rater agreement. Are there any know
issues with Fleiss kappa calculation in R? Even when I supply mock data
with total agreement among the raters I do not get a kappa value of 1.
instead I am getting negative values.
I am using the irr package version 0.70
Any help is much appreciated.
Thanks and Regards
M
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2009 Aug 12
1
MCMC sampling question
Hello,
Consider MCMC sampling with metropolis / metropolis hastings proposals
and a density function with a given valid parameter space. How are MCMC
proposals performed if the parameter could be located at the very
extreme of the parameter space, or even 'beyond that' ? Example to
express it and my very nontechnical 'beyond that': The von Mises
distribution is a circular
2003 Jul 18
3
question about formulating a nls optimization
Dear list,
I'm migrating a project from Matlab to R, and I'm
facing a relatively complicated problem for nls. My
objective function is below:
>> objFun <- function(yEx,xEx,tEx,gamma,theta,kappa){
yTh <- pdfDY(xEx,tEx,gamma,theta,kappa)
sum(log(yEx/yTh)^2)
}
The equation is yTh=P(xEx,tEx) + noise.
I collect my data in:
>> data <-
2006 Oct 02
2
R function to compute kappa statistics for two vector
Dear R-user,
Did anybody know how to calculate the kappa statistics of two vectors for
the agreement? for example:
a<-c(0,1,0,0,1,0)
b<-c(0,1,1,0,0,1)
I know the percent of agreement is 3/6, but how to get the kappa?
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2008 Aug 22
3
simple generation of artificial data with defined features
Dear R-colleagues,
I am quite a newbie to R fighting my stupidity to solve a probably quite
simple problem of generating artificial data with defined features.
I am conducting a study of inter-observer-agreement in
child-bronchoscopy. One of the most important measures is Kappa
according to Fleiss, which is very comfortable available in R through
the irr-package.
Unfortunately medical doctors
2008 Sep 07
1
cohen's kappa
Dear all,
I have a question on Cohen's kappa:
Assume I have two datasets, one has 500 objects, 10 methods and the other,
1000 different objects, 20 different methods. Could I compare between the
two datasets to conclude the 10 methods are more "concordant" than the 20
ones by looking at some output, for example, cohen.kappa{concord} ?
One more, could anyone explain in brief,
2023 Feb 20
1
uniroot violates bounds?
Le 18/02/2023 ? 21:44, J C Nash a ?crit?:
> I wrote first cut at unirootR for Martin M and he revised and put in
> Rmpfr.
>
> The following extends Ben's example, but adds the unirootR with trace
> output.
>
> c1 <- 4469.822
> c2 <- 572.3413
> f <- function(x) { c1/x - c2/(1-x) }; uniroot(f, c(1e-6, 1))
> uniroot(f, c(1e-6, 1))
> library(Rmpfr)
>
2007 Jun 26
3
inter-rater agreement index kappa
Is there a function that calculates the inter-rater agreement index
(kappa) in R?
Thanks ../Murli
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2008 May 29
1
Kappa distribution
Hallo all,
I am looking for an R implementation of the four parameter kappa
distribution (cdf, pdf, quantile, and ransom numbers), or at a minimum,
the generalized logistic distribution.
Any suggestions?
Thank you very much,
Serguei